'96 Metro Trans Problem

[hot_sd]

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.

[Chacheska]

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!

[hot_sd]

Happy New Year to you too. 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.

[Chacheska]

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!

[Chacheska]

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.

[hot_sd]

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.

[Chacheska]

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!

[hot_sd]

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.

[Chacheska]

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.

[hot_sd]

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

[Chacheska]

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!!

[hot_sd]

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. Bit of a digression from fixing cars but really a lot of this stuff is not difficult.

[Chacheska]

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!

[Chacheska]

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!

[hot_sd]

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.