'96 Metro Trans Problem

Just bought a '96 Metro 4 cyl 3 speed auto with 118,000 miles. Trans was slipping and down a qt of fluid. I filled the trans but it didn't help. The trans fluid was light brown so I dropped the pan and screen. Magnet looked like a furry Chia pet. Cleaned pan, magnet and screen and replaced close to a gallon of fluid. Didn't help. and after awhile the fluid was again light brown. Problem: Car always shifts fine when cold for the 1st 15 minutes. After it gets fully warm it bypasses 2nd gear and shifts into 3rd at 20 mh. If I manually shift into first from a dead stop it starts out in second and will shift into 3rd when I manually shift back into drive at 20 mph. If I start out in drive and manually shift into 1st gear at 13 mph it will shift into second and I can manually shift back into drive at 20 mph which will again put it into 3rd. If I try to manually shift into 2nd at any time it goes out of gear completely. If I disconnect the round connector near the VSS under the hood it stays in 3rd gear all the time in the drive position. DTC's are 753, 758 and 780 (shift solenoid A electrical, shift solenoid B electrical and shift malfunction). ALSO ...... something is draiing my battery. With a healthy battery I start out with the battery light off or very dim but as the car warms up over time the battery light gets brighter as the voltage drops. I had the chargig system checked at Autozone but they said the battery and alternator were both fine but I only drove a mile and a half to Autozone when it was cold when I got it checked so it wasn't fully warmed up. I suspect that whatever is draining the battery drains it to the point that one or both of the shift solenoids isn't getting the voltage to them that they need to shift the gears after awhile which causes the shift problems. Does that make sense? When I hooked up a multimeter to the battery and started the car the voltage dropped a little with the running lights on. When I turned on the marker ights the voltage dropped a little more. When I turned on the headlights it dropped a little more. When I stepped on the brake it dropped 1/2 volt and when I put it in drive it dropped another 1/2 volt. It seems like the problem is the alternator even though Autozone said it wasn't. No codes relating to the electrical problem other than the shift solenoid codes. When I shut the car down the battery slowly goes back up close to full charge about half an hour after the test using the lights, brake, etc. I was also wondering if the shift solenoids may be shorting out and overheating the trans fluid which would be making it turn light brown. Does any of this make sense? Any other possibilities or tests? How do I check the shift solenoids? Could it be the TCM? Thanks in advance! Happy new year!!

To get a diagnostic of transmision with home tools is pretty hard why not get a used transmission from the junkyard and save yourself some headaches or get the solenoids from a used transmision.

I presume the slipping was fixed with fluid change. If you disconnect the shift solenoid connector and if the tranny is placed in the “D” position it will stay in third – that is normal behavior. If you can manually shift into second and first with the connector disconnected then the problem is either in the solenoids or the control system/sensors. Have you checked the manual shifting with connector removed.

You can test the electrical functionality of the solenoids by removing them and either checking continuity with a multimeter or by applying 12V to the terminals – you should hear a click. Testing mechanical functionality is harder – if you have an air compressor you need to rig up a tube into the solenoid opening and force compressed air at about 40PSI and see if the solenoids vents the air when energized. If so the solenoid is fine.

Skipping second due to a control system fault means both solenoids are turning off simultaneously which is a bit odd. Second is generated by turning off the second brake solenoid – this closes the 1-2 shift valve which in turn activates the intermediate servo and the clamps the second brake band to the sun gear drum which locks the sun gear in place so only the planet carrier and ring gear(s) rotate.

The first test to do would be the manual shift test. If the solenoids short out I suspect that the ECU should automatically current limit – if not the circuit generating the control voltage may overheat and burn out. The brown fluid is most likely due to either burnt fluid or clutch material from the clutches or band.

As for the electrical problem – it could possibly affect the ECM and cause side effects like this.

Thanks for the great tips. That's the sort of info I was looking for. To answer 2 questions, the fluid is still light brown even after putting in 3/4 of a gallon of fresh fluid. As I recall, the 2nd gear problem persisted even after I manually shifted through the gears with the solenoids disconnected. NEW INFO. Today I went to where the car is stored and noticed I left the ignition o which drained the battery. I put in a fully charged battery. Before I drove it I took out fuses #1 and #2 which control the headlights. I didn't want the battery to drain too fast. Lo and behold, I drove the car for 45 minutes without the tranny slipping! It went right through the gears. I took it to a second Autozone where they did another alternator test with the car fully warmed up. No problem with the alternator or battery. The whole time I drove the car no codes or battery light came on. The dash was clear. Now the bad news. I drove it another 10 minutes and the trans started slipping again! At the same time I heard a loud buzzing under the dash. I reached under and felt a connector mounted on the steering column vibrating. I don't know what it is because I don't have a '96 shop manual. I decided to turn the headlight switch on (I was trying anything) and the buzzing stopped. If I put the marker lights on only it started buzzing again. I kept the switch turned on and drove a few more miles with the trans acting up like it did before. I then plugged the 2 fuses back in. Fuse #2 sparked when I put it back. Fuse #1 didn't. The buzzing was now gone in all modes. I drove 15 miles home and no codes or warning lights lit on the dash. When I was 2 miles from home the trans was really acting up. I had a hard time keeping it in ANY gear from a dead stop. Once I got it to 3rd and stayed over 20 mph I didn't have any slipping problems. When I got home I checked the battery and it was fully charged ater driving 35 miles so whatever was draining the battery stopped. I will repeat the manual shift test with the connector seperated tomorrow. I have a feeling it's an internal trans problem and that the thinning out of the tranny fluid after it gets hot is causing the shifting problem. Possibly not enough internal pressure for the weak seals. Just guessing. One important question, please. Is it best to disconnect the solenoids and leave it in the 3rd gear default mode while I try to solve this problem? I was told that tranny slipping is what burns up the trans. I'm guessing the 3rd gear only mode will cause less damage than the constant slipping even though the car has to start from a complete stop in 3rd gear. Thanks very much!

If the problem is there when the connector is disconnected then, yes the problem is internal to the trans. Once the connector is out the gears are manually selected by the manual valve and the car electrics do not play a part in the tranny's operation.

Slipping is usually one of two things that come to my mind. Firstly the line pressure may be too low. This could be due to a failing oil pump or a faulty primary/secondary pressure regulator inside the valve body. The other is that the friction material on the clutch plates and possibly the band has worn out and as a result is not gripping correctly. Unfortunately if this is the case the tranny will have to be rebuilt.

Slipping can distroy the friction metarial on the clutches and bands and render them useless but also the slipping can be caused by clutch discs and bands that are nearing the end of their life. Overheating is another leading cause of trannies burning up - you may want to consider an oil cooler flush. Has the tranny been serviced regularly.

I would measure the line pressure first. This should be done at both idle and stall (WOT) conditions. You can do it yourself or have a mechanic do it for you. You shoud read 28-56PSI - idle and 71 - 99PSI at stall in forward. In reverse 78-113PSI at idle and 150 - 200PSI at stall.

There is a more comprehensive test involving line pressure and engine rpm to actually pinpont which assembly is responsible (forward clutch, direct clutch, one way clutch etc). If you want to start getting into all this I would suggest buying the service manual for the trans. ATSG does a good rebuild manual that has all this info - the website is www.atsgmiami.com

I just want to thank you very much for taking time to try to help me with this problem. I'll try some of your suggestions and take it from here. I just bought the car from a third party so I don't know any history. I guess the electrical problems have nothing to do with the trans problem like I thought they did. I only paid $150 for the car. Once again, thank you very much!

I did think of two more questions. Why does the trans always shift normally when cold for the first 15 minutes and get worse once it's warm/hot? This last time it ran 45 minutes before slipping with fuses #1 and #2 removed. I need to understand that. Second, what is the connector on the steering wheel column that was buzzing and why did it start buzzing as soon as the trans started slipping after 45 minutes of no slipping? There must be some correlation there.

It is not uncommon for transmissions to work when cold and then malfunction when hot - in fact this applies to many things. The fact is things change in size/expand when hot. In the case of the slipping for example the forward or direct clutch drums can expand when hot. If the clutch disc thickness is below spec the clearance between the piston and the discs would be sufficient to prevent slipping when cold. When hot the drum could expand to the point the clutch discs can no longer engage fully.

No idea about the buzzing - the only thing in the steering column that I'm aware of related to the tranny is the shift lock and the simply controls shifting out of park. Nothing controlling the insides of the tranny there as far as I'm aware.

Another thing to double check although I doubt if it is the problem is the tension on the cable from the gas pedal to the thottle valve in the tranny. You can find this on the top of the tranny. If it too slack you can get shifting problems.

I really appreciate all your help. I like to try to understand the underlying cause and related issues. The one thing that I need to know that you didn't answer is if it's a better idea to unplug the shift solenoids for the time being and leave it in default 3rd gear mode until I fix the problem by swapping trannies or fixing any related electrical problems. That's kind of important to me so if you could answer that last question I'd be very grateful. Thanks again for sharing your knowledge with me.

Yes, you cannot do any damage to the tranny by keeping it in third - it's more the fact that it may not be good for the engine as it will cause the engine to labor moving from a dead stop.

Glad to help and hope you get this resolved.

Yeah, I was a ittle concerned about the engine rpm's at a dead stop in 3rd. The short time I did drive it in 3rd I was surprised that the engine seemed to accelerate fairly well with no lugging from a stop but I'm sure it's not doing the engine any good. I haven't driven it the last couple of days to test the manual shift with the solenoid connector disconnected yet. By the way, thanks for the ATSG URL. Great site! I can't thank you enough for all your time. I have a unique probem with my '94 that I'll post in a few minutes.

Yes, the ATSG book for the MX17 is quite good and I used it when I rebuilt my tranny last year. It is not so good for the newer cars as it does not cover the OBD2 control system too well (mine is a 2000 Metro) but I also have the chevrolet factory manual which has a good deal on the newer trannies and the shift control system/solenoids and together they have all the info you need for diagnosing and rebuilding the MX17 tranny.

Like most people, I can work on a lot of mechanical things but trannies are alien to me. They seem very complicated. It's probably easier for me to swap it out for a good one. Just posted my rather unique problem with the '94 I have. I hate to tell you this but I have 7 of the little suckers. Two 92's, three '94's, a '96 and a 2000. One '92 is a parts car. The other '92 and the '96 are automatics. The rest are standards. I keep finding them dirt cheap and just can't resist. This is worse than having a gambling problem!

Well, they are really not that complicated - main thing is understanding how planetary gearsets operate. Everything else in the tranny is there to make this gearset work by locking and unlocking different sections of the gearset. Some newer trannies have more fancy features like using a pulse train to gently engage the solenoids etc but the basic principes remain the same.

As for collecting metros - I know of someone locally who buys them cheap and non - working, fixes them and then sells them on. I think he does good business since the gas prices went up.

Mine all run, most of them very well, except for that parts car. Most of them need a little work. I don't know if different topics are assigned to different people but if not, and you get a chance, please read my other post with the '94 problem. That's a wacky one. Who am I conversing with?

Karl

Sorry yes I did read it and really cannot think of anything with the tranny that could cause something like this. Manual trannies are of course much simpler than autos - they use a regular gearset (not a planetary gearset) and when they malfuction it is due to something like a broken gear which is not very common. It sounds like an engine issue to me - possibly fuel starvation. Someone else may have a better idea.

O.K. Thanks for all your help. You didn't leave a name but that's O.K. Those two problems with the '96 and the '94 are my biggest two problems. If I can at leeast solve one I'll be happy. Happy new year!

Happy New Year to you too. :smile: And also one other tip that I forgot to mention - since you have no idea of the service history of the vehicle when you swap out the tranny I would suggest doing an oil cooler flush. My tranny has been serviced regularly and I was still suprised to see the amount of crud (clutch metarial) that came out of the oil cooler which I did following the rebuild. I think oil cooler flushing should be part of a regular service but it is not a standard procedure. You can get aerosol based oil cooler flushes. If you do not have a tranny parts place near you you can get it online. I've found that several tranny parts suppliers will not sell to "members of the public". You can buy the flush and also a cooler line fittings kit directly from life automotive (www.lifeautomotive.com) and they will ship it to you.

A plugged oil cooler can cause overheating and can burn out the tranny.

That's an excellent tip and more excellent advice that I'm very grateful to you for. These are the kinds of things I need to know. It will be a part of my regular maintenance schedule from now on. You've given me great advice and I can't thank you enough. Ciao!

Update on the trans slipping. I dropped the pan again and saw more furry chia pet on the magnet. That's troublesome after driving only about 300 miles since the last time. Anyway, I disconnected both shift solenoids. I checked the wiring and didn't find any visible breaks. However, the plastic connector end on the red wiring was black on one side as if it was burnt. The end of the yellow wire looked O.K. although that end is darker and harder to see. Is the red one shorting out at the connector? Which color wire is solenoid A and which color wire is solenoid B? Thanks.

What's a furry chia pet? Is it a dog. I have seen what clutch material looks like collected on the magnet but I can't say I've ever seen this chia thing.

It is possible that if the clutch discs and/or band are shedding the clutch material large chunks may be disintegrating and causing larger than normal amounts to end up in the system. Either that and/or the fact that maybe the tranny was not regularly serviced before you got the vehicle.

If you want to find out if any of the solenoids are shorted out or if the wires are connected correctly to the solenoids disconnect the circular connector and measure the resistance between each lead to the solenoid and ground - you should read 8 - 20 ohm. A lower reading could mean there is a problem with the coil. A high reading could mean a break in the wire or inside the coil.

A & B are generic terms - in the MX17 I believe B refers to the second brake and A refers to the direct clutch solenoid. Not sure which is which with regard to the color but I believe the one at the front is the second brake or B solenoid. I don't think the dark spot necessarily means that anything is wrong - if the coil had shorted out if the ECM has been designed well it should current limit and prevent anything overheating/burning.

You've never seen those Chia pet commercials on TV around Christmas? Cha cha cha Chia! Anyway, the reference was supposed to imply the soft, furry feeling metal shavings that have accmulated on the magnet. The same thing I found just a couple of weeks ago when I dropped the pan. The front wire is the red one. That's the one that had the blackish burned looked spot on the plastic connector. The metal male and female connector ends looked O.K. as far as I can tell by looking at them. It didn't appear the metal was burned. I disconnected the solenoids last night when I dropped the pan. Which end of the connector do I do the wire test on with the multimeter? I assume the end going to the ECU? The battery obviously has to be connected. I disconnected it because I wasn't sure any voltage going to the solenoid would hurt them when I disconnected them. What about the ignition? Does it have to be on to do the test? I read somewhere that the ignition needs to be off when disconnecting the solenoids. Just a little more specifics and I'm ready to go. Thanks very much for more great advice!

Hmm...can't say I've seen the commercials so I have no idea what a Chia is - I don't watch much TV and when I do I skip the commericals as I have a DVR. I guess it looks like tranny fluff. Have you seen a chia.

No the resistance to be measured is the solenoid coil resistance so you need to disconnect and then insert the meter probes into the tranny end. You can also measure the resistance on the ECM side - I think it should read about 2 ohm - I can double check the manual - but I don't think you need to test the ECM side. If you already have the pan down you take take the solenoids out and also do the measurement directly if you like. Don't have to worry about the battery in this case and in general when you do resistance/continuity checking you do not want any external voltage sources in the circuit you are testing and so all such sources must be disconnected. So if you are doing any continuity checking that involves the car battery you will need to actually disconnect it from the circuit - either by pulling a fuse or removing a wiring harness or whatever. Also no need to worry about the ignition.

As for pulling out the connector - I don't think it really matters that much - if you are not moving then it may be better to turn the engine/ignition off as both solenoids will be energized.

Chia pets are lttle porcelain (I believe) objects in the shape of a head, dog, cat, etc. You spread seeds on the item and water it. Over time it grows green 'hair'. It's a really stupid gift that you only see for sale around Christmas when the commercials hit the airwaves. Never saw one in person.

Anyway, I really do appreciate the testing tips. I'm a landlord that can do roofing, siding, house wiring, plumbing, drywall, etc. When it comes to car mechanics I'm pretty good but when it comes to automotive electrical wiring and testing that's my weakness. So, if I understand you correctly, I disconnect the solenoids connectors in the trans and do the test at each connector on the tranny itself, not the wiring that runs up though the trans into the wiring harness, correct? I also do the test with the battery disconnected. If I test the ECM side I would probe the wires at the under hood round connector, testing the wires at the end of the round connector leading into the wiring harness. Is that correct? In testing the internal solenoid contact, do I ground the neg end of the multimeter probe to the chassis and touch the positive probe to the solenoid? When checking the two wires on the round conector to the ECM do I touch the neg probe from the multimeter to the one wire and the positive to the other wire or always have the neg probe grounded while I test each of the two wires seperately? Whew! Hope I didnt confuse things too much. I apologize for my testing ignorance.

Oh well - thanks for enlightening me about Chia - I also leant something today :grinyes: Interesting.

As for testing - it is pretty strightforward - all you have to do is to disconnect the circular solenoid wire between the ECM and tranny and then insert the multimeter into the wires leading to the solenoids into the tranny - one to one of the wires and the other to the ground - and measure the resistance. Repeat for the other wire.

To test the resistance on the ECM side repeat above test but this time to the section of the connector that goes to the ECM.

Also you may want to do a voltage check to see if the ECM is powering the solenoids correctly. While circular connector is removed start the engine and place into first gear and then measure the voltage coming out of each of the wires between that wire and ground. The voltage should be around 2V.

Regarding electrics in general - all of the stuff in a car (excluding the ECM/sensor system) is relatively straightforward as most of it involves basic electrical theory. If you can understand the flow of electrons and also a few concepts like Ohm's law and the concept of electrical energy that's pretty much it. It may also help to understand how to reduce a circuit using Thevenin and Norton's theorms but not really necessary. The ECM and the sensor networks require a little more understanding of solid state devices and and a bit more advanced data comms and simple modulations techniques like PWM but in all not that difficult to grasp. I'm sure there is some simple reading material on basic electric principles that you could read sometime to get a better understanding.

Thanks VERY much for the straightforwardness of your explanation. That's easy to understand for any layman. The only question I have regarding checking the voltage of the connector with the car in first gear ....... should I check the hospitalization plan on my health insurance so that when the car runs me over I'll be sure I'm covered? I guess if I was stupid enough not to jack the front of the car up first I deserve to get run over. All seriousness aside, thanks a lot for providing me with easy to understand answers to my questions. Electronic wiring and economics have always been two of my weaknesses. I guess my brain isn't wired for those things. Now THERE'S a wiring problem you won't be able to help me with!!

:grinyes: Sorry - I was not clear about the first gear - just keep the car stationary, move the shift lever into 1, 2 or D (your choice) and then take a reading. You can have someone sit in the drivers seat while you take the meaurement. They can keep the brake pedal depressed and also engage the handbrake to be safe. The ECM will energize both solenoids as it wil not sense any movement from the VSS.

And as for the other thing - yes, I guess for somethings like mathematics people either have an aptitude for it or not. And I don't mean numbers but abstract mathematics like advanced calculus or at an even more abstract level analysis (like proof by induction). That does require a particular kind of mindset. However, with most things I think anyone can pick up the princples provided the learning material has been suitably designed.

I personally like simple explanations myself. I do encounter technical ariticles in my journals that sometimes have such heavy mathematical content that I find it hard to follow (and I have studied math to a very advanced level). I mainly design circuits and integrated circuits for use in areas like wireless and satellites and mainly in new product development in emerging technologies and so keeping current with the latest developments at the research level is critical as one has to understand the theory in order to design the system correctly but it can be a challenge.

I'm sure you have what it takes to get to grips with the electrics - who know you may even fix all the electrical stuff in your car one day. :smile: Bit of a digression from fixing cars but really a lot of this stuff is not difficult.

I was just having fun with you. I don't have anyone to help me so a hydraulic jack and two jack stands will have to suffice. I've always been right brain oriented so intricate technical info has alsways been a bit difficult for me. If things are explained in a simplistic manner initially and gradually more complex I don't have a problem. Thanks for the simplistic approach. I'll post my findings tomorrow or Sunday. By the way, I admire the level of education you've managed to achieve in your field. VERY impressive!

I was just having fun with you. Even at the peak of my youth I wouldn't have been fast enough to get in front of a car after putting it in gear. I don't have anyone to help me so a hydraulic jack and two jack stands will have to suffice. I've always been right brain oriented so intricate technical info has alsways been a bit difficult for me. If things are explained in a simplistic manner initially and gradually made more complex I don't have a problem. Thanks for the simplistic approach. I'll post my findings tomorrow or Sunday. By the way, I admire the level of education you've managed to achieve in your field. VERY impressive!

I think you can get away with the handbrake and wheel chocks - but if you want to be safe you can use the jackstands. And yes about explanations - that's what I was getting at. Even for me if some of the technical articles had a simple explanation with some nice pictures first that would help so much more. The same applies to those who teach - some just know how to explain and some do not (although they may know the subject well). Anyway good luck with the tranny repairs.

O.K., hot_sd. I finally got the readings you asked me to get. I checked the leads to the ECM by disconnecting the round solenoid connector. With the multimeter set at 200m the readings were .3 (3ohms?) at each wire. I also checked the leads to the solenoids at the other end of the round connector and got the same .3 reading on each wire. I then diconnected the wires from the solenoids. I had problems taking readings at the solenoids themslves and the disconnected wires that lead up through the trans. The readings were jumping all over the place. I took sandpaper and got down to bare metal for a solid ground and had to clean the contacts well because they had lots of trans fluid on the contacts and in the connectors. After that I got steady readings of .1 at each solenoid and also .1 measured at each wire going up through the trans casing to the ECM. I'm kinda wondering why the readings to the ECM were .3 at the connector going to the ECM but only .1 at the wires inside the tranny. You initially said the readings should be 8 to 20 ohms but later stated they should be 2 ohms. If you look back at your former posts you'll see what I mean. I may have misinterpreted what you meant so please clarify. I didn't test the energized solenoids yet because that would involve me filling the trans with fluid and I want to make sure I've tested all I need to test inside the trans before moving on. One question, please. I'm old school when it comes to wiring. How is it possible to have an electrical connection inside a liquid environment? I've never seen wires inside a fluid filled tranny pan before so when I saw them for the first time I was quite surprised. How is an electrical connection made when the components are sitting in tranny fluid?

I believe what I said in the original post was that the resistance measured across the solenoid coils should be 8 - 20 Ohm and the resistance measured going into the ECM should be 2 ohms. So these are the measurements on each side of the circular connector - onc side into one of the 2 solenoids and the other side into the ECM. These reading are as per the service manual. I do have a spare solenoid around somewhere - I will take a reading off that and post the results in the next few days when I get a chance.

Also make sure that you are reading the multimeter results correctly. Is it a digital one or an analog one. On the older ones you have to take the reading and multiply by a scaling factor - so if you were for example on the 100K range and you got 0.3 reading then the resistance would be 0.3 * 100 K or 30 K ohms. Typically the scaling factor would be your range. Did not understand the 200m range - did you mean 200 Meg Ohm.

And also regarding sticking the wires in tranny fluid - I believe oils do not conduct current well (unlike water) and so it should be safe to immerse electrical wires into oil In fact I believe high power transformers (of the type you find coming off high voltage power lines) are encased and immsered in oil to aid cooling.

Thanks for explaining the wires-in-oil question. Interesting. I used a digital multimeter. In the DC (left) section of the meter the readings from most sensitive to least sensitive are 200m, 2000m, 20v, 200v and 2000v. I assume the 'm' means milivolts which means I took the wrong reading off the meter. The right side is the AC side. I'll have to find the manual regarding the ohm scale and do it again. For the sake of clarity, what do you mean by "across the solenoid coils"? I don't see anything resembling coils. Do you mean the male contacts inside the tranny? Maybe this is just too complicated for me. I tried to precisely describe the exact tests I did in my previous post. Let's start with this question. Was any of that right? Forget the fact I took a milivolt reading ..... did I test the wires in the correct way by always grounding the neg end of the meter probe (black) and testing each individual wire and solenoid with the other end of the probe (red). If I saw a diagram or someone doing it in front of me it would be easy. I think the verbal terminology is what's screwing me up. For the sake of simplicity, let's call the two wires at the round connector leading to the ECM as wires a and b. The two wires from the round connector leading into the tranny to the solenoids as c and d. The two wires at the solenoid contacts within the trans as e and f. Lastly, the two internally mounted trans male connectors that the internal female wires attach to as g and h. If none of those are the "solenoid coils" please tell me where they are. If you're getting tired of explaining this to me I understand. I just think the difference in terminology is the main communication problem. Thanks for your patience to this point.

Sure - no problem - I can explain as many times as you want :grinyes: You may not always get a prompt reply though depending on my workload - this week I have to attend a wireless conference in addition to work and other stuff so things are a bit busy. But anyway - getting back to the tranny issue - yes, I guess I confused you with the terminology. The 2 wires going in to the solenoid form a coil. When energized the coil becomes an electomagnet and attracts the valve at the center. This opens the input passge to the vent. In the tranny this allows the relevant valve passae to either open or close and thereby energizes the intermidiate servo or direct clutch piston. Donlt worry if you don'f follow this but I was just saying "across the solenoid" in another way. So to get back to describing it with your lettering system - measuring the resistance between a and b should give you 2 ohms. Measuring between c and ground or d and ground should give you 8 - 20 ohms. If you get a high value then I would measure (e & gnd) and (f & gnd). If they read ok ( 8 - 20 ohms) you have a break in the wiring harness from connector to tranny. If you get a high reading at e and f as described or a very low reading the coils are open or shorted. You cannot really meaure anything useful at g or h.

And the other test I mentioned is to run the engine place the gear into D and while the car is not moving meaure the voltage (note voltage not resistance) between (a & gdn) and (b & gnd). You should see 2V.

Hope this was more clear :grinyes:

Hey, that lettering system makes it much easier for me! I was at my warehouse checking things before you sent me your reply so this is what I already found. First, my multimeter has DCV, DCA and ACV sections, none of which measures ohms. The section not labeled has ranges of 2000k, 200k, 20k, 2000 and 200. I have to assume this is the ohm range. With the meter set to 20k these are the readings I got. Ground to a and ground to b leading into the ECM each reads 5.7. Ground to c and ground to d leading to the solenoids reads .11 each. Hmm! Ground to e and ground to f, which should be the same as doing it from a and b (except the readings are taken from the red and yellow wires in the tranny leading to the ECM instead of the round connector to the ECM), is 5.8 and 5.9 which is just slightly higher than the a/b reading. Measuring "across the solenoid" by bridging a to b gave me a reading of 10.25. With the meter set to 20k does that equate to a reading of 10.25 ohms or 1.025 ohms? I assume it's 1.025. Either way, it doesn't fall into the 2 ohm criteria you outlined. What's much worse is that the 8 - 20 ohm reading I should have got testing c and d separately to ground gave me a reading of .11 each! I can try taking that again tomorrow. I took the reading twice so I'm positive the .11 is correct. What is that reading in ohms? I filled the trans and will do the other test in drive tomorrow to see if I get the 2 VOLTS. I understand if you can't get back to me in a timely matter. I'm VERY appreciative of any time you can give me so if you can't get back to me for a couple of days or so I completely understand. My main question now is if I'm using the right setting on the multimeter and reading ohms correctly. And what is that .11 I'm getting at c and d? Should e and f be connected to g and h while testing c and d or disconnected? Once again, thanks VERY much!! With your help I'm getting there.

New info. Took the car for a ride today. After the usual 15 minutes with no problems the trans started slipping again so I disconnected the solenoids. Starting out from low gear it's actually in second gear. Switching into second goes out of gear entirely. Drive is drive. If I start off from a stop in drive, it stays in drive because it's in 3rd gear default mode. Reverse gves me problems with the solenoids disconnetced. It won't go into reverse unless you give it some gas and will slip out of reverse if the revs slow down enough. Doesn't do that with the solenoids connected. Will re-check the c and d readings tonight as well as a and b to ground in drive to check the reading to the energized solenoids.

This might be my last post on this subject which will probably make a lot of people who have followed these posts happy. I jacked up the front of the car, put it in drive and tested connectors a and b to the ECM. The reason that this is probably my last post is because I took the reading and then sat in the car to write it down. After that, without thinking, I put the car into park. Needless to say I heard a lot of clatter and noise in the tranny. What I did was probably the equivalent of driving down the road and shifting into park. Not feeling any motion in the car because it was jacked up, I just automaticaly put it in park without realizing it was in drive with the wheels spinning. I immediately shut off the car but it was too late. I turned it on again and put it in drive, 2nd, low and even reverse and the wheels wouldn't turn so if the tranny wasn't fried before it is now. For all the good it will do, the readings at a and b, each grounded, was 10.4 volts. WAY more than the 2 volts you mentioned, hot_sd. I re-read the readings at c and d and got .01 each which is different from the .11 I got yesterday. If the tranny is cooked I'll probably junk it or sell it as a parts car now. I'm as burned out as the tranny. The trans may have had a problem before but at least it ran. All that work and testing down the drain. Oh well ........

No reason to junk the car, JDM and used transmissions are available for very reasonable prices, and they are not difficult to install.

Hey, that lettering system makes it much easier for me! I was at my warehouse checking things before you sent me your reply so this is what I already found. First, my multimeter has DCV, DCA and ACV sections, none of which measures ohms. The section not labeled has ranges of 2000k, 200k, 20k, 2000 and 200. I have to assume this is the ohm range. With the meter set to 20k these are the readings I got. Ground to a and ground to b leading into the ECM each reads 5.7. Ground to c and ground to d leading to the solenoids reads .11 each. Hmm! Ground to e and ground to f, which should be the same as doing it from a and b (except the readings are taken from the red and yellow wires in the tranny leading to the ECM instead of the round connector to the ECM), is 5.8 and 5.9 which is just slightly higher than the a/b reading. Measuring "across the solenoid" by bridging a to b gave me a reading of 10.25. With the meter set to 20k does that equate to a reading of 10.25 ohms or 1.025 ohms? I assume it's 1.025. Either way, it doesn't fall into the 2 ohm criteria you outlined. What's much worse is that the 8 - 20 ohm reading I should have got testing c and d separately to ground gave me a reading of .11 each! I can try taking that again tomorrow. I took the reading twice so I'm positive the .11 is correct. What is that reading in ohms? I filled the trans and will do the other test in drive tomorrow to see if I get the 2 VOLTS. I understand if you can't get back to me in a timely matter. I'm VERY appreciative of any time you can give me so if you can't get back to me for a couple of days or so I completely understand. My main question now is if I'm using the right setting on the multimeter and reading ohms correctly. And what is that .11 I'm getting at c and d? Should e and f be connected to g and h while testing c and d or disconnected? Once again, thanks VERY much!! With your help I'm getting there.


Yes, I would say that the unlabelled range is the ohms range. Reading your post I'm a bit confused - if a and b lead to the ECM you cannot read across the solenoid with those - it would be c and gnd or d and gnd. I think there is again some confusion about the labelling. In any case I would not bother with the ohm reading on the ECM - these are for my car which is the 2000 Metro and the ECM is different so I apologize for giving you incorrect info. The solenoid resistance should be what I said though - I will post this info tomorrow as I have to work on the car. I would just read the resistance across the solenoid and draw some conclusions from that. As for reading the meter - you should see a sclae factor somewhere on the display - so if it says 0.2 and kohm in the scale factor the resistance is 0.2*1000 = 200 ohms.

New info. Took the car for a ride today. After the usual 15 minutes with no problems the trans started slipping again so I disconnected the solenoids. Starting out from low gear it's actually in second gear. Switching into second goes out of gear entirely. Drive is drive. If I start off from a stop in drive, it stays in drive because it's in 3rd gear default mode. Reverse gves me problems with the solenoids disconnetced. It won't go into reverse unless you give it some gas and will slip out of reverse if the revs slow down enough. Doesn't do that with the solenoids connected. Will re-check the c and d readings tonight as well as a and b to ground in drive to check the reading to the energized solenoids.

Since you have problems with the connector disconnected I would discount the ECM as being the problem. My initial guess based on the symtoms described is that the valve body is plugged up. Either that or a multiple of other problems like worn clutches/band and/or a failing oil pump. Have you tried the tests I suggested originally in post 5. In general if you disconnect that shift connector and you still have problems you can discount the electrical control part as being the problem. The solenoids could have meachanical problem though - something could have jammed it open or shut.

This might be my last post on this subject which will probably make a lot of people who have followed these posts happy. I jacked up the front of the car, put it in drive and tested connectors a and b to the ECM. The reason that this is probably my last post is because I took the reading and then sat in the car to write it down. After that, without thinking, I put the car into park. Needless to say I heard a lot of clatter and noise in the tranny. What I did was probably the equivalent of driving down the road and shifting into park. Not feeling any motion in the car because it was jacked up, I just automaticaly put it in park without realizing it was in drive with the wheels spinning. I immediately shut off the car but it was too late. I turned it on again and put it in drive, 2nd, low and even reverse and the wheels wouldn't turn so if the tranny wasn't fried before it is now. For all the good it will do, the readings at a and b, each grounded, was 10.4 volts. WAY more than the 2 volts you mentioned, hot_sd. I re-read the readings at c and d and got .01 each which is different from the .11 I got yesterday. If the tranny is cooked I'll probably junk it or sell it as a parts car now. I'm as burned out as the tranny. The trans may have had a problem before but at least it ran. All that work and testing down the drain. Oh well ........


I think the a and b reading are OK. Again it probably depends on the ECM but that voltage is more than enough to energize the solenoids so the low gears should be present while in "D". Based on all the info I would discount the ECM as being the problem.

As for the shifting into park - you may be OK since the wheels were off the ground. First off I guess the shift interlock system is not working unless they wer not present on the older cars - you should not be able to shift into park without depressing the brake pedal. Have you tried driving the car since this happened. Since the tranny has a standard open differential you cannot draw much conclusion about whether it is working or not with the wheels jacked up - you need to load the wheels.

I've gotta tell you, it's nice to hear some positive feedback from all who have replied. I figured someone would have called me an idiot by now. I'm sure some of you have and thanks for sparing me from seeing it in print! Metromightymouse, (great name, by the way) I've been told changing a trans isn't all that bad. The only problem I ever encounter that makes jobs like this really tough is breaking 10 year old bolts free. I spent close to an hour last night trying to free the 14mm bolt that holds the rear strut shaft so I can replace a bent strut on this car. After wire brushing the bolt head and threads, spraying the hell out of it with penetrating fluid and hitting it with a flat ended punch and hammer to shock it free I still couldn't get it to turn. I don't have torches, just a propane torch which I'm going to try tonight. I don't know if that will generate enough heat, though. I think I should try to find out what caused the trans to go bad before I put another one in, though. Dieinterim, are you referring to a stall test done through the port on the side of the tranny using a gauge? I read something regarding that in the '94 shop manual I have. I was relunctant to do that because I read if it's not done right it can do some damage. I guess I should try it anyway because that info is important in trying to diagnose a problem. Thanks! Hot_sd, I guess I took every reading but the one I needed to take .... the reading across c and d. Will do that tonight. Obviously that one has to be done without the car running since the round connector has to be disconnected in order to take that reading. I spoke to a friend of mine who said I most likely fried the parking gear but not necessarily the drive gears. I did put the car into reverse and drive inside the warehouse and it went back and forth a few feet so maybe I'm O.K. I suppose I should change the trans fluid again a third time in case there's more shavings from the park gear. I was just tired last night and got frustrated. After a good night's sleep I'm ready to plug away again. As I mentioned, the readings of c grounded and d grounded were .11 each the first time and .01 each the second time with the meter set at 20k. I don't know why they came up different. I will take them one more time tonight and also take a reading across the c and d terminals and see what I get. The only scaling on the meter I see is movement of the decimal depending on which setting I have dialed in. I have a dogged detrmination to finish what I start so please forgive me for keeping this post going. I apologize to all those who find this boring and thanks to everyone for their valuable input. Trannies have always been the one part of a car I know nothing about.

I'm sure that nobody thinks of you like that :grinyes: Based on your latest drive test I would concentrate on the insides of the tranny unless you want to finish the electrical reading just as a learning exercise. If you want to measure line pressure you will find the numbers in post 5. A valve body clean is something you can do yourself since it can be removed without taking the tranny out. It is the object that the filter is bolted to. However, you will need to get the service manual as it has all the assembly/disassembly steps in there.

As for the issue about shifting into park - my guess is you should be OK especially as you can drive it. Remember that with a open differential very little power is transmitted when the wheels have no load. So there should have been very little force on the park lock lever when you shifted into park. And FYI there is no parking gear as such. The front part of the tranny contains the planetary gearset which is a fairly standard 3 speed Simpson type. At the end of the tranny a toothed gearwheel then engages a rear countershaft which transmits the drive back to the diff. When you place the tranny into park a lever pops up and wedges itself into the teeth of the main gearwheel. I did take some photos of the insides of the tranny when I rebuilt it but this was one section I did not photograph or I would have posted it up if you would like to have seen it.

Thanks for the compliment (you should see how far I've taken it in photos I'll post soon). The nice thing about doing a swap like this is you replace nearly everything that could have been broken, there is very little left that might not be working. With all the metal in the trans it is most likely used up and time to replace it. There should also be a huge difference between bolts and nuts in a wheel well and the ones holding the motor and trans together and also the motor/ trans mounts. Some of them may be tight but none of them should be rusted in like that.

Hot_sd, you're absolutely right, I bridged a and b to get that reading leading to the ECM rather than the solenoids. DUH!. C grounded and d grounded gave me a reading of .11 each the first time and .01 the second time. I don't know why I got two different readings. I'm pretty sure the meter was set at 20k each time. I don't see any scale factor other than the decimal location moving across the viewfinder depending on the range selected. If the solenoids could have mechanical problems how would that have happened and is there a way to check for that? I thought they were strictly electrical. I have a '96 shop manual coming in about two weeks. I'll check it out and see what I have to do to do the valve body cleaning. As for shifting into park from drive, from what your descriging it sounds as if the teeth of the main gearwheel may have been damaged. I may not have had it right when I said the park gear but I figured there was some gear in there with teeth that may have been damaged. I only moved it a couple of feet in forward and reverse. I need to get it out on the road and see. First I have to get that 14mm nut off the strut mount and change that strut. I read a post you submitted regarding having a problem with your alternator belt slipping. You're such a detail oriented guy that it seemed funny that a problem like that would have you stumped. I've had that problem on my '94 for years. I just tighten the belt every couple of months. Metromighymouse (Jon). I still think the 10 year old bolts holding the trans in place will be a pain just 'cause they're outside and exposed to the elements. A friend of mine swears by a product called Aero Kroyl as a penetrant. Industrial quality stuff, he says. I'll start looking for a trans. I saw a '96 motor, trans and cat converter with 78,000 miles on it on eBay sell for $150 in Wisconsin a week ago. That's a bit far at 800 miles, though. What does JDM mean? Dieinterim (Blake), thanks for your tips also. I don't know hot_sd's name yet. The one thing I would like to know after all of this is how to read that multimeter to get ohms. What does 20k equate to on the meter based on the examples I gave in my earlier post? I still think I need to find out why the trans is shot at 118,000 miles before putting another one in there. A tranny should last longer than that unless someone beat the hell out of it.

I have the factory service manual for my car (2000 Metro) and it does cover the tranny controls quite well as well as some service work like valve body disassembly. However, it does not cover a full rebuild - the ATSG manual (link I posted in an earlier post) does a fairly good job although it only covers controls on the older cars. I was considering getting the factory manual for the tranny but I don't think I need that now. Given my car is only a 2000 with 86K miles now (had about 72K when I rebuilt it) it was kind of suprising. The intermidiate band snapped near the hinge point. I guess it may have been a defective part at manufacture. The rest of the tranny was is very good condition but to complete the rebuild I pulled everything apart and replaced all the clutch discs and plates as well as all the seals and o-rings. Point being that your tranny may actually be in good ocndition with the lack of service by a previous owner causing clogging up of the valve body wih clutch material or something similar. If you have the time and want to learn something about auto trannies you can have a go at fixing it.

If the gear wheel teeth have become damaged due to the little mishap then you will notice it when you drive - you may have a vibration or something like that. In that case if you plan to repair the tranny you can probably get a used gear wheel.

Only way to check for mechanical jam in the solenoid is to remove and inspect the opening or test with compressed air (I think I posted the technique somewhere earlier in this thread).

Yes, sometimes my brain freezes up also (referring to alternator post). Probably at that time some people were thinking that I was an idiot also :grinyes:

And my name BTW is Ravin.

Hey there, Ravin. Since I own 6 running Metros and one parts car I can put this '96 aside for awhile and play with it. One of my '94's is pretty beat so that leaves me with 4 roadworthy Metros. Once I get that strut replaced I can road test the trans. I also have a 2000 Metro with about 180,000 on it. Bought it last year for $150 'cause it needed an alternator (which I got out of a boneyard for $22.50) speed sensor and speed control. The Speedo and odometer don't work and the lady I bought it from said that was the diagnosis from a repair shop. Anyway, you're killing me on this ohm thing. You're never going to tell me about those readings I took, are you? You're gonna make me suffer. I'd really like to know what the .11 on the meter equates to in ohms. I guess I can find out locally. I think I've got all the mileage I'm going to get out of this particular post and have enough info to do what I need to do. I'm having increasing trouble replying to a post. The last one took 15 minutes. I keep getting denied when I try to post something so if you don't hear from me again it's because I'm being denied the ability to post for some reason. Thanks VERY much! You posted about 98% of the info regarding this trans problem and I can't thank you enough for all the time you've donated. Hopefully as I get more involved with my Metros I'll be able to return the favor for you and others.

Karl

JDM = Japanese domestic market
Japan has significantly different laws concerning cars. They are required to rebuild or replace the motor approximately every 50,000 miles so they started shipping those motors to the states as cheap replacements. Since they are already shipping the motors it is easy to also ship good transmissions along with them. So we get to buy low mileage good motors and transmissions for a very reasonable price.

As far as difficult to remove bolts, the one for the strut that you are dealing with is steel in steel, perfect for rusting in. the great majority of what you would be removing from the engine and trans will be steel in alloy or aluminum or whatever they decided to make these babies out of. The point being there is very little "rust seize", and they should be reasonably easy to get out. The one real exception is the exaust manifold to pipe bolts, they take lots of coaxing to get out.

Good luck, btw I plan to have a bigger photo of my dash on my "Offerings" post and I should have the tail end of my car in my signature tonight.

I guess I did not read all of your previous post. Unfortunately as I cannot see what your meter is reading I would only be guessing when the reading means. If you can post up a picture of what you are seeing (pic of the meter showing the range selected as well as what it is reading) then we could tell you what the ohm reading is.

If you plan to work on your tranny yourself post back and I can tell you what tools to get etc. The one downside with repairing trannies is that the tools are very expensive although there are good deals to be had on ebay. I bought all the tools used (apart from the clutch pack compressor) on ebay. Parts are inexpensive - would cost about $100 for a full rebuild kit (clutch discs & plates, band and the gasket pack) and you can get many used hard parts if you need to replace anything that looks damaged.

Look forward to getting help from you on some stuff in the future!