bad torque converter symptoms


wyatt_earb
01-25-2007, 01:00 AM
I'm not sure, but I believe my torque converter is going out. What signs should I be looking for if this is going on?

MT-2500
01-25-2007, 01:16 PM
I'm not sure, but I believe my torque converter is going out. What signs should I be looking for if this is going on?

Noise and excessive stall rpm.
What is your doing or not doing?
Does lock up work?
Any codes?
What year and engine and transmission and mileage?

Blue Bowtie
01-25-2007, 02:05 PM
Top Ten signs of a bad torque converter:

#10 - It's found between an engine and transmisison which have the words "Daimler" or "Chrysler" cast in them somewhere;

#9 - Doesn't claim "Additional Oil" on Form 1299 with its tax return;

#8 - Your torque converter has been "balooned" more than Dick Cheney's arteries;

#7 - When you're not looking, it crawls off the flexplate and takes twenty minute paid "breaks" on the input shaft;

#6 - You wake up in the morning and find your torque converter sleeping with your neighbor's wife;

#5 - The lockup clutch has more "slop" than Madonna;

#4 - Your torque converter has been off on an Extacy binge for six days straight;

#3 - The hookers in Times Square tell you "We would, but we don't want to get caught with someone with a torque converter like yours.";

#2 - Sneaks out at night and holds up convenience stores for all the ATF they have on hand;

The Number 1 reason your torque converter is bad - Your torque converter has appeared twice on "America's Most Wanted".

Blue Bowtie
01-25-2007, 02:11 PM
A little more seriously, though, what year is the truck? Most '95 and newer trucks should store an error code if TC performance is below a programmed threshold. Older trucks can be scanned with a capable scanner to monitor both engine RPM and VSS (driveshaft RPM) and you ocan compare them to determine slip/stall speed under driving conditions.

blazee
01-25-2007, 02:11 PM
Top Ten signs of a bad torque converter:

#10 - It's found between an engine and transmisison which have the words "Daimler" or "Chrysler" cast in them somewhere;

#9 - Doesn't claim "Additional Oil" on Form 1299 with its tax return;

#8 - Your torque converter has been "balooned" more than Dick Cheney's arteries;

#7 - When you're not looking, it crawls off the flexplate and takes twenty minute paid "breaks" on the input shaft;

#6 - You wake up in the morning and find your torque converter sleeping with your neighbor's wife;

#5 - The lockup clutch has more "slop" than Madonna;

#4 - Your torque converter has been off on an Extacy binge for six days straight;

#3 - The hookers in Times Square tell you "We would, but we don't want to get caught with someone with a torque converter like yours.";

#2 - Sneaks out at night and holds up convenience stores for all the ATF they have on hand;

The Number 1 reason your torque converter is bad - Your torque converter has appeared twice on "America's Most Wanted".

^^ Bwahahaha :lol:

wyatt_earb
01-25-2007, 09:43 PM
1988 4x4 2.8 s10 blazer w/ 85,000 miles on it.

1) its been eating gas, which it believe might have to do with this.
2) I'll be driving to class and its will jack up in rpms and I have to slow down. The tranny itself shifts fine, sometimes takes its time going to OD, but doesnt go hard.
3) I've noticed it seem to shake, but that might be a rough ride b.c my ball joints are almost gone.
4) it has burned up tranny fluid something awful, which wasnt burned up say 6 months ago.
5) About a year ago when it would go shake/shutter like crazy when going into OD, almost like the rear end was going out. So I checked the AFF level and it was a tad low, but not much.
So I did a quick fix and put in some lucas slip fix, real thick tranny fluid. The problem went away and I had no problems, until now. So I believe the TQ is going out, why I dont know.........

Does it sound like a bad TQ to you? If so, how much fun will this be to replace?

wyatt_earb
01-25-2007, 10:22 PM
Also, I did change the tranny filter and did some flushing. A friend of mine works at a dealership and we used their flush machine. We didnt flush it until clean b/c the ATF was pretty burned up, smelled god awful, and I was advised not to completely flush it. Their "tranny" guy told me to flush it around half way then drive it for awhile and make sure it doesnt slip like the tranny is going to go. So far it has worked fine, but would a complete flush actually cause the tranny to go out??? I've neve heard this, but its what I was told.

MT-2500
01-25-2007, 10:26 PM
1988 4x4 2.8 s10 blazer w/ 85,000 miles on it.

1) its been eating gas, which it believe might have to do with this.
2) I'll be driving to class and its will jack up in rpms and I have to slow down. The tranny itself shifts fine, sometimes takes its time going to OD, but doesnt go hard.
3) I've noticed it seem to shake, but that might be a rough ride b.c my ball joints are almost gone.
4) it has burned up tranny fluid something awful, which wasnt burned up say 6 months ago.
5) About a year ago when it would go shake/shutter like crazy when going into OD, almost like the rear end was going out. So I checked the AFF level and it was a tad low, but not much.
So I did a quick fix and put in some lucas slip fix, real thick tranny fluid. The problem went away and I had no problems, until now. So I believe the TQ is going out, why I dont know.........

Does it sound like a bad TQ to you? If so, how much fun will this be to replace?


If you got a year on it after Lucas fix you are doing good.
If the transmission is not slipping or making a noise just keep on driving it.
The converter is not your problem.
And if a converter goes the rest of the transmission usually goes with it.
Carb or fuel injection on it? If carb how is that choke?
And remember cold weather will make the use more gas.:grinyes:
But Check tune up and engine running.

Blue Bowtie
01-25-2007, 10:44 PM
Forget what I mentioned about the error codes, since the '88 will not have that capability. Drain the transmisison and change the filter. Refill with clean fluid, drive it for several hundred miles, and change it again if necessary. At only 85,000 miles there shouldn't be enough wear of friction surfaces to risk no-drive on a fluid change. It might be a good time to install a drain plug while the pan is off.

The slippage and even shudder under load may be a clutch, TCC, or the band servo. Those could all be symptoms of dirty fluid and the things that go with it, like a sitcky TCC solenoid or poorly sealing clutches and shaft seals. The longer it is driven that way, the greater the potential for real damage.

FWIW, transmission additives are usually a big mistake. The burned odor you now smell could be a result.

wyatt_earb
01-25-2007, 11:11 PM
But why would it be burnt up at 85,000 miles, this is an old city vehcle and they're good about general maintance on their vehicles. I was thinking about flushing the rest of the fluid out and seeing what happens. Although I've read on the internet that you should never flush a transmission with burnt fluid b/c it'll cause the transmission to go out. Tomorrow I'll check the fluid for "particles" in it, possibly being chunks of seals etc...

Also when I had it looked at a year ago, for the whole shuttering thing, the guy said something was going out with the torque converter. Said to unplug the wire going to the transmission if the lucas didnt make it go away. If I remember correctly he said it had something to do with it going into overdrive, and electric torque converter maybe, I cant really recall. I'm going to stop by the local transmission shop and talk to them, I believe they look at it for free....

About the tune up, I've already done that, along with a long long list of other things. The gas problem wont go away, which is why I'm thinking this tranny problem has something to do with it. Like I said, while going 65ish sometimes it just shoots the rpms up and it struggles to go 55-60.

Blue Bowtie
01-25-2007, 11:20 PM
The reason you were advised against fully changing the oil is that on a transmission with some apparent slippage, and with potentially worn friction surfaces, the contamination in the oil may be the only thing prodiving enough friction to provide clutch engagement. Once the oil is drained and clean, particle free oil is added, there is nothing left to make clutches grab. That's pretty rare at only 85,000 miles, even if it is all city driving.

Since your transmission apparently didn't exhibit any more slippage after the oil change, change it all and get a complete fill of clean fluid. Clean oil can lubricate better, help flush out contaminated valves, clean up sealing surfaces, and allows for overall better hydraulic operation of the trans.

wyatt_earb
01-25-2007, 11:28 PM
Any reccomendation on a flush to use, if any?? And any reccomended type of ATF I should use. I greatly appreciate the responses.

Blue Bowtie
01-25-2007, 11:34 PM
Refill with plain Dexron III in whatever brand you like so long as it meets the GM H36174 spec.

If you still experience shudder while in OD, and unplugging the TCC solenoid solves it, the lockup clutch may be slipping or the lockup solenoid valve may have a problem (among other possibilities). The solenoid problem is not really uncommon on a TH700-R4, and the solenoid can be changed with only the oil pan removed. If you're having a trans tech check it out, they should be able to diagnose that.

wyatt_earb
01-25-2007, 11:41 PM
Forgot to mention, the rpm thing doesnt just happen in OD. I put it in drive once while it did this, doesnt always do it, and it kept doing it. It doesnt shudder anymore, rpms just go up and it wont stay at 65ish. Really dont know how to explain it....

Could the fact I have bigger than reccomended tires be the proplem, causing the speed sensor to mess up? When it says I'm going 60 I'm really going around 68.

Also could a bad solenoid on the transmission be the cause of the burnt up fluid? Doesnt the TCC open and close a valve, possible closing and not opening, and causing the ATF to sit in the trans and get burnt up?

silicon212
01-26-2007, 01:31 AM
If the TCC isn't locking the converter in 4th, that would cause burned fluid (due to overheating as a result of excessive TC slippage in OD) as well as a burned 3-4 clutch. Assuming this is a TH700R4/4L60 trans, that is ...

Your symptoms nearly mirror slippage in the 3-4 clutch, this would be a cause of burned fluid. Rebuild time! While you're in there, check and replace the TCC solenoid - the majority of TCC failure is caused by a failure in this part.

A bad torque converter, in MY OWN experience, will cause the car to have next-to-no-power at lower speeds, along with a 'clicking' noise coming from under the vehicle (stator slippage within the TCC). Once at speed, the converter won't give many symptoms of impending failure or failure in progress. If lockup is engaging in 4th, the converter is completely out of the equation in OD.

wyatt_earb
01-26-2007, 12:17 PM
I really dont believe the transmission is burned up, it shift fine, doesnt slip out of gear, or make any noise. But the blazer does lack power, I know its a 2.8, but its still a dog. Also while driving at a consisitent speed if I tap the break the rpms dont go up, like they do in my 87 2.8 s10 truck. Guess I'm going to have to look at this. Anthing I should look for while driving or while working on it?

MT-2500
01-26-2007, 12:47 PM
But why would it be burnt up at 85,000 miles, this is an old city vehcle and they're good about general maintance on their vehicles. I was thinking about flushing the rest of the fluid out and seeing what happens. Although I've read on the internet that you should never flush a transmission with burnt fluid b/c it'll cause the transmission to go out. Tomorrow I'll check the fluid for "particles" in it, possibly being chunks of seals etc...

Also when I had it looked at a year ago, for the whole shuttering thing, the guy said something was going out with the torque converter. Said to unplug the wire going to the transmission if the lucas didnt make it go away. If I remember correctly he said it had something to do with it going into overdrive, and electric torque converter maybe, I cant really recall. I'm going to stop by the local transmission shop and talk to them, I believe they look at it for free....

About the tune up, I've already done that, along with a long long list of other things. The gas problem wont go away, which is why I'm thinking this tranny problem has something to do with it. Like I said, while going 65ish sometimes it just shoots the rpms up and it struggles to go 55-60.

From what you described in this post and have told us so far.
Your transmission is on it's last leg.
Burning fluid and dropping out of gear is not good and points to internal transmission problems.
A lot more than a bad converter.
A new filter and another bottle of Lucas may put a band aid on it for a while.
But if you you are going to keep the truck it is another transmission or rebuild time.
Good Luck MT

wyatt_earb
01-28-2007, 11:48 PM
Took it to a tranny place that does free diagnosis, he said its definetly the TCC. Said it could be the break switch or the solenoid, and if neither of those then its not worth fixing. Was told if I get the TCC to start kicking in, then to take the transmission pan off and jack up the blazer as high as possible to allow most of the fluid to drain out. Said while the fluid was burned up it has low miles on it and he didnt feel any "grit" in it. This sound right to anyone? And I've never messed with a brake switch, said I might just be able to clean it off....

J-Mech
01-29-2007, 12:08 AM
If you have a shutter, or think maybe it is slipping it probably is. If it is an old sity truck it has done a lot of start and stop driving which would be espically hard on the converter. Torque converters do not necessarily take the trans out with it. I have replaced many converters and not the trans. The reason for not changing the fluid, because it can make it fail is true. There are additives in tranny fluid that clean. Worn fluid lacks the additives (these are what depletes in all oils and the reason for changes) so it cleans that dirty old tranny too fast causing the clutches to fall apart and fail. Replacing the torque converter is reletively easy and inexpensive. You should just bite the bullet and do it.

wyatt_earb
01-29-2007, 12:12 AM
This is why I took it in and had it looked at, he drove it around and had a computer hooked up. Said the converter wasnt the problem it was the TCC kicking in and out, when it was going out, and not its completely not locking in causing the fluid to get burned up.

MT-2500
01-29-2007, 09:57 AM
This is why I took it in and had it looked at, he drove it around and had a computer hooked up. Said the converter wasnt the problem it was the TCC kicking in and out, when it was going out, and not its completely not locking in causing the fluid to get burned up.


Is it still dropping out of OD down to 3 gear?
Is the TV cable adjusted good?

Are you using silicone or sealant on the oil pan gasket?

It would be rare for a converter to burn fluid.

On a normal take off at what MPH does it upshift?

wyatt_earb
01-30-2007, 04:11 PM
Maybe I didnt understand what he was saying, but he said when you apply the break a valve is suppose to open in the tranny, allowing it to cool down. He said this is the problem and to check the break switch, which he said even if the lights are working it still might not be functioning correctly. And he said if i still couldnt feel it locking in then it was most likely the solenoid. From what I understood the TCC locks in not matter what gear you have it in, and when its not working, like on mine, then the motor will run at 500-1000 rpms hire. So it goes into OD and all gears fine, but once your cruising at a consistent speed the TCC is suppose to lock in. You can test this by driving down the road around 55mph and lightly touch the break. If the TCC is working properly the motor should rev up, but this doesnt happen on mine b/c its always reved up. I hope I made that as clear as mud...... I'll do my best to answer any other question. THANKS FOR ALL THE ADVICE SO FAR!!!

MT-2500
01-30-2007, 05:23 PM
Is it still dropping out of OD down to 3 gear?
Is the TV cable adjusted good?

Are you using silicone or sealant on the oil pan gasket?

It would be rare for a converter to burn fluid.

On a normal take off at what MPH does it upshift?


Answer these questions for more help with it.:grinyes: .

It sounds like you need to find another trasmission man.
I never heard of one working quite like that.

wyatt_earb
01-30-2007, 11:57 PM
I used rtv gasket on the pan when I changed the filter. It never dropped out of OD. I'm not sure what the TV cable is.... And I'll have to take it out and watch the mph while its shifting, to be honest it seems to run and shift fine. Never shifts hard or slips, but it'll go up in rpms while driving 65+ for and extended distance and it acts like its not all the way in gear. But itll ride at 55mph fine. I'm going to try the break switch out this weekend and if that doesnt work then I'll try out the solenoid. Hope this helps...

MT-2500
01-31-2007, 10:18 AM
I used rtv gasket on the pan when I changed the filter. It never dropped out of OD. I'm not sure what the TV cable is.... And I'll have to take it out and watch the mph while its shifting, to be honest it seems to run and shift fine. Never shifts hard or slips, but it'll go up in rpms while driving 65+ for and extended distance and it acts like its not all the way in gear. But itll ride at 55mph fine. I'm going to try the break switch out this weekend and if that doesnt work then I'll try out the solenoid. Hope this helps...


Rule no 1
Do not use RTV gasket sealer on the 700R4 pan gasket.
That may be some of your problem.
The sealer plugs the OD band servo release drain hole.
And can burn up band and trans fluid and transmission.

berniescout
01-31-2007, 10:56 AM
what should you use?? just a dry gasket?? another sealer?? or just wipe it w dexron III. i am about to do mine for the first time and am using mobil 1 atf any thoughts??

MT-2500
01-31-2007, 01:31 PM
what should you use?? just a dry gasket?? another sealer?? or just wipe it w dexron III. i am about to do mine for the first time and am using mobil 1 atf any thoughts??

No Moible 1 .
No dope or additive.
No flushes.
No sealer or greese or fluid on pan gasket.
Just clean dry cork pan gasket and new filter and what the book calls for on transmission fluid type.

wyatt_earb
01-31-2007, 11:14 PM
Ok. I just changed the filter and I'm going to have to take the pan off again so I'll buy a gasket for it. Is the best way to drain the fluid to jack up the vehicle as high as posslible and let it set over night? This is what I was told, told this will drain most of the tranny fluid.

blazes9395
01-31-2007, 11:47 PM
The 2.8 700R4,s are notorious for being poorly performing trannies. If the tranny is not locking up and you drive it like that especially at higher speeds, for a long time, you will overheat it, and eventually damage it. Shuddering is a common tell tale sign of a overheated(ing) convertor. Probably also is a reason why your getting burnt fluid. This does not only mean its your convertor, you could have other tranny problems too.

No SES codes will come up on this tranny, as it is way to old. But if you have a bad VSS, TPS, coolant, especially coolant sensor, as sometimes you don't get a SES light for a boarderline bad coolant sesnor in these old trucks, it will not allow the tranny to lock up. Its designed like this as it allows the engine/transmission to warm up when its cold, but if it has a bad/no, or common cold reading, the ECM will not allow lock-up by default. If any of these sensors don't work, it will not lock up either.

Also to check to see if in fact your TCC is working, there is a TCC ground pin in the diagnostic link under the dash. I don't remember which pin it is, but if you ground it it will force lock-up. Do this when you going about 40mph, ground it at this point, if the RPMs go down and it locks up, you TCC is working. If there is no lock-up when you ground the pin, you have a tranny, or convertor problem.

Good Luck!

wyatt_earb
02-01-2007, 12:38 AM
I know the TCC isnt working, b.c it doesnt lock in. I believe you can tell this by lightly applying the breaks, when going a consistent speed, and the rpms dont go up. Plus I was told by the tranny guy that this is why I'm getting bad gas mileage. Also I have replaced the coolant temp sensor on the intake, infront of the TBI, but not the one by the manifold.

blazes9395
02-01-2007, 12:46 AM
Also to check to see if in fact your TCC is working, there is a TCC ground pin in the diagnostic link under the dash. I don't remember which pin it is, but if you ground it it will force lock-up. Do this when you going about 40mph, ground it at this point, if the RPMs go down and it locks up, you TCC is working. If there is no lock-up when you ground the pin, you have a tranny, or convertor problem.

Good Luck!

Using this method above, will overide the whole circuit, and directly link to the harness right to the tranny. If this method does not lock-up the convertor, no matter what you do with things like the brake switch (applying the brakes lightly), or anything else, you will not get lock-up.

Yes this will defiently give you poorer gas milage, and eventually overheated tranny too.

MT-2500
02-01-2007, 10:15 AM
Ok. I just changed the filter and I'm going to have to take the pan off again so I'll buy a gasket for it. Is the best way to drain the fluid to jack up the vehicle as high as posslible and let it set over night? This is what I was told, told this will drain most of the tranny fluid.

It does help on the dribbling/mess but you can not get all of the fluid out with a pan drop. Just 5-7 qts.
And make sure you check the small drain hole from the servo on the right side.
If you look at pan and gasket there is a notch cut out for it.
If sealer has ever been used it could be stopped up.
Wipe the bottom of transmission pan gasket are clean and transmission pan and put a good cork gasket on dry.

wyatt_earb
02-02-2007, 02:58 AM
Should I try this? And if so, which pin grounds the TCC? Thanks.

Blue Bowtie
02-02-2007, 10:34 AM
http://72.19.213.157/files/ALDL.gif

Grounding ALDL pin 'F' will only work if the connection at the transmisison is intact. Also, it will only function if the auxilliary contacts on the brake pedal switch are closed, and there is 12VDC present on the purple wire at the switch.

Grounding this pin will operate the TCC solenoid valve completely independent of the ECM, so any other possible parametric causes for the TCC to remain open will not be an issue.

You need to be sure the vehicle is either in motion or that the vehicle is raised and secured with all drive wheels off the ground.

wyatt_earb
02-02-2007, 12:38 PM
Let me make sure I've got this right. I ground the "F" pin, while driving at a consistent speed? Something like 45mph? And if I dont feel a drop in RPMs, TCC kick in, then theres some serious shit wrong?

blazes9395
02-05-2007, 03:48 PM
Let me make sure I've got this right. I ground the "F" pin, while driving at a consistent speed? Something like 45mph? And if I dont feel a drop in RPMs, TCC kick in, then theres some serious shit wrong?

:lol: Well, it doesn't look too good if this is infact the case.

wyatt_earb
02-05-2007, 09:54 PM
I havent been driving it much at all lately, tihnking about just selling it. It's too damn cold to mess with it right now, -20 with windchill. But surprisingly it starts like a champ, I let it run for awhile since its so cold.

frehol
02-12-2007, 02:36 PM
http://72.19.213.157/files/ALDL.gif

Grounding ALDL pin 'F' will only work if the connection at the transmisison is intact. Also, it will only function if the auxilliary contacts on the brake pedal switch are closed, and there is 12VDC present on the purple wire at the switch.

Grounding this pin will operate the TCC solenoid valve completely independent of the ECM, so any other possible parametric causes for the TCC to remain open will not be an issue.

You need to be sure the vehicle is either in motion or that the vehicle is raised and secured with all drive wheels off the ground.

Is there a wiring diagram over the TCC circuits?
Can I by monitoring the F-pin see if PCM is trying to lock up the TCC?
Fom what I read here I figure the wiring should be something like:

+12v----[break switch]-----[TCC solenoid]----[F-pin]----[PCM]---Ground

Just curious.
/Freddy

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