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Need your help to make this a good sticky thread. I'll start off with my experiences. Please add your tips and suggestions of SOLUTIONS you've had.


No TCC Lockup:
1. Monitor the PCM with a good scanner or datalogger to see if the PCM is commanding lockup. I have come across B-bodies whose PCMs never command lockup.
A. If it's not commanding lockup, check the brake switch input, cruise control input.
B. You can disable lockup in the PCM programming by setting the lockup speed to max (255mph or something like that).
2. If PCM is commanding lockup but TCC is not locking up, check the following things:
A. TCC enable solenoid (accessible by dropping the pan, held in with two 10mm screws, goes up into the pump, has a plastic hat on it, hardwired to the wiring harness). Resistance should be 8-14 ohms (I think). It should also click if you put 12V across it and hold it so that the hat is facing up.
B. If a '95-96 4L60E, the PWM solenoid is also required for lockup. You can stake the valve it acts upon in the full-open position as shown here.
C. The converter clutch material may be worn out.

Intermittent TCC Lockup:
1. Check PCM with a datalogger or good scanner to see if PCM is commanding the unlock and relock. If so, check:
A. TPS for spikey output (this is a guess)
B. Intermittent false-on signals from brake switch and/or cruise control release switch.
C. Custom Programming may have TCC lock/unlock setup with improper hysteresis at the speed you're driving.

2. If it's not the PCM, check:
A. TCC enable solenoid may be flaky.
B. Converter clutch material may be just about worn away. Requires torque converter replacement.

TCC stuck locked:
1. See if PCM is commanding. If so,
A. programming is incorrectly setup
B. internal short is keeping the TCC enable solenoid grounded (on).
2. If not the PCM:
A. wiring harness may be grounding the TCC enable solenoid wire, keeping it on.
B. Converter is physically stuck? I doubt it.


Just going off the top of my head here. Additional thoughts and ideas welcome! Post away!
 

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ok, noit sure this goes here, but it might so I'm goign to post it.

FYI the trans is stock.

I was cruising through Wal-mart parking lot last night(empty section off to the side) and under light throttle may 10-15mph, then i gave it a little mroe gas and as it prematurely (felt like it) shifted into third gear the car bogged down and the engine lugged liked I applied the brakes or lost power sort of. I had to give it a substantial amount of gas to keep gaining speed and was only tring to go 30-35mph if that (wasn't watching the speedo but wasn't but maybe 1/4 throttle).

So then I went down the street for a little drive and it shifted and felt fine (normal) until it hit thrid and fourth gear. It again felt like I was riding the brakes like something was binding up, but it didn't lurch or shudder at all. I let off the gas to see if it would coast and it didn't seem to coast like normal. I then tried third gear manually (stuck it in D) and it seemed to be still binding (for lack of better term).

I decided to take it to AAMCO this morning to have them road test it and see if any codes or silent codes came up and nothing came up. They did however tell me that its going into lockup to early and that was why it felt like it was binding in thrid and fourth.

After searching here on the forum and talking with my brother, I decided to do afew more quick and easy tests since i had something to go on (TCC). First, I disconnected the battery to see if that would change anything and went for a drive. As I suspected, it didn't change anything, but it was worth a try. Then I disconnected the TCC from the PCM (blue connector wire 11 and its tan&black) and went for a drive after picking the car up.

Again, with the TCC disconnected now I went for a drive and as soon as I hit thrid and fourth gears it felt like it was binding or like I was riding the brakes and didn't really want to coast. I hit several stop lights on purpose to make sure i could really test it and it just kept doing it. I then decided to go into fourth gear and then put the car in Neutral (while moving) then back into fourth.

I have no idea why, but it all the sudden drove normally again. That is until i had to stop and go again. So I verified that this was actually happening a couple more times, then reconnected the TCC to the PCM and tried (4th to Neutral to 4th) again. Again, this made the car drive normally until I had to stop and start moving again. Then i had to repeat this process for i not to feel like it was dragging.

BTW, I made sure it was in Neutral while driving for at least 3 seconds before going back to 4th or 3rd. If I didn't give it enough time to fully go into Neutral it seemed to keep holding back.

Sorry for the long post but does anyone have a clue as t what could be causing this?

I would appreciate any insight someone could give me as this trans needs to last until I can fund my T56 and it needs to get me from SC to Baltimore when I'm ready for the swap.

Thanks,
Jesse
 

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this thread should be sticky'd. thanks for the info, op
 

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I never knew i had a locking up TC. hmmm,shows what i know about Trannys and that stuff.

def should be a sticky.
 

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ok, noit sure this goes here, but it might so I'm goign to post it.

FYI the trans is stock.

I was cruising through Wal-mart parking lot last night(empty section off to the side) and under light throttle may 10-15mph, then i gave it a little mroe gas and as it prematurely (felt like it) shifted into third gear the car bogged down and the engine lugged liked I applied the brakes or lost power sort of. I had to give it a substantial amount of gas to keep gaining speed and was only tring to go 30-35mph if that (wasn't watching the speedo but wasn't but maybe 1/4 throttle).

So then I went down the street for a little drive and it shifted and felt fine (normal) until it hit thrid and fourth gear. It again felt like I was riding the brakes like something was binding up, but it didn't lurch or shudder at all. I let off the gas to see if it would coast and it didn't seem to coast like normal. I then tried third gear manually (stuck it in D) and it seemed to be still binding (for lack of better term).

I decided to take it to AAMCO this morning to have them road test it and see if any codes or silent codes came up and nothing came up. They did however tell me that its going into lockup to early and that was why it felt like it was binding in thrid and fourth.

After searching here on the forum and talking with my brother, I decided to do afew more quick and easy tests since i had something to go on (TCC). First, I disconnected the battery to see if that would change anything and went for a drive. As I suspected, it didn't change anything, but it was worth a try. Then I disconnected the TCC from the PCM (blue connector wire 11 and its tan&black) and went for a drive after picking the car up.

Again, with the TCC disconnected now I went for a drive and as soon as I hit thrid and fourth gears it felt like it was binding or like I was riding the brakes and didn't really want to coast. I hit several stop lights on purpose to make sure i could really test it and it just kept doing it. I then decided to go into fourth gear and then put the car in Neutral (while moving) then back into fourth.

I have no idea why, but it all the sudden drove normally again. That is until i had to stop and go again. So I verified that this was actually happening a couple more times, then reconnected the TCC to the PCM and tried (4th to Neutral to 4th) again. Again, this made the car drive normally until I had to stop and start moving again. Then i had to repeat this process for i not to feel like it was dragging.

BTW, I made sure it was in Neutral while driving for at least 3 seconds before going back to 4th or 3rd. If I didn't give it enough time to fully go into Neutral it seemed to keep holding back.

Sorry for the long post but does anyone have a clue as t what could be causing this?

I would appreciate any insight someone could give me as this trans needs to last until I can fund my T56 and it needs to get me from SC to Baltimore when I'm ready for the swap.

Thanks,
Jesse
I know this isn't yhe proper thread for this,, but i'm gonna give the answer anyway. From the STICKIES no less.

"15. Horrible noise in 4th and feels like the brakes are on: overrun clutches are applying due to a cracked or leaking forward piston. Overrun clutches will be worn out after 30 seconds of this behavior. Car can be safely driven in D. R&R."

Chris
 
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