Torque converter locking up IMMEDIATLY!!

7709 Views 17 Replies 4 Participants Last post by cahall, Mar 16, 2013

kzman78

Discussion Starter · Mar 6, 2013

Ok, here's what's up. First off, 1994 Pontiac 25th Ann. TA w/4l60E. I back out of my driveway, put it in gear, touch the gas and......... the f#***** torque converter locks up IMMEDIATLY!!!! It's like having a manual trans!! My ? is, how do I disconnect to tc lockup selinoid to see if it is the noid or the tc? Here's a little backround on the trans, rebuilt by my local shop 500 miles ago, all TCI internals, new 2200 stall converter, rebuilt pump, borg warner sprag, code fix ect.... I tried to use good quality parts. Soooo anyway, with car in D,3,2, tc locks and stalls car. Staight to 1 the acts like normal until u touch the gas then it locks up almost immediatly. R is normal. Once moveing in 1 the car shifts to 2 on its own without moveing shifter. It will also get to D by 20-25mph after moveing shifter to D. Kickdown work as it should. Sorry for the long post but I want to be as complete as possible. If any other info is needed just ask! Any ideas or info? Also, anyone that can setup the trans paramiters in the Central WI Area? My local shop says they can only change them while their computer is hooked up but it returns once they unhook it. Thanks again techies!!!

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Racy Roadmaster

· #2 · Mar 6, 2013

I dont consider myself an expert on the 4L60E boxes,I have changed a few but never really got into the internals much. I believe there are 8 or 9 selenoids in your trans and one of them controls converter lock up.I believe the PCM gets its signal from the speed sensor and the PCM signals one of the trans selenoids to lock up the converter. Their are many people on this site that have a ton more knowledge that I on this trans,but I would think its either a bad selenoid or speed sensor. Before doing anything I would crawl under your machine and check to see that all the
wiring to your trans is plugged in properly. Also check to see that no wires are pinched in between the trans and engine . What does the shop say about your trans, they should have some input. good luck. ed

kzman78

Discussion Starter · #3 · Mar 6, 2013

Thanks, racey! I have done that, all plugs are good and vss is working. No broken wires, trans worked great when parked 2 days before, then backed out of driveway and instantly had problem. Also, no pwm in 94. Again, Thanks for your input!!

cahall

· #4 · Mar 6, 2013

Since your trans is a '94, you only have 1 solenoid that controls lock up. This is the solenoid that goes into the pump. It's located right next to the filter neck. The solenoid works off hot and ground. The solenoid has constant hot, and the computer sends the ground for lock up. It's possible that the ground wire is grounded and sending ground all the time. This can be internally, if a wire in the harness is pinched and touching something metallic. It could also be external, and in the wiring harness. If you completely disconnect the harness, it will be in "fail safe", which means it will try to start in 3rd and will have max line pressure. However, this will help diagnose the problem. If the converter doesn't lock up with it disconnected than you know it's external. Other causes could be a mechanically stock TCC (lock up) solenoid, a stuck lock up valve in the pump or a bad converter. This should all be covered under warranty if it was just built 500 miles ago.

Frank

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Racy Roadmaster

· #5 · Mar 6, 2013

Thats right the 94's have OBD1 , my 96 Roady has OBD2 and of course
a PCM. I believe your trans is just getting a signal to engage the lock up function,and thats what leads me to thinking it could be wiring or mis wiring. ed
PS -Was your trans an exchange or are you sure you got your orig. back? From what I know, the transmissions in these cars 94,95,96 changed with each model year so even though they will physically fit into each other,they wont work .

cahall

· #6 · Mar 6, 2013

What brand converter is it?

Frank

cahall

· #7 · Mar 6, 2013

Racy Roadmaster said:
PS -Was your trans an exchange or are you sure you got your orig. back? From what I know, the transmissions in these cars 94,95,96 changed with each model year so even though they will physically fit into each other,they wont work .

This is a very good point, and definitely worth mentioning. A 1994 HAS to have a 1994 transmission.

Frank

kzman78

Discussion Starter · #8 · Mar 6, 2013

Yes, it is my 1994 trans. As for the TC, that I'm not sure of as the trans shop got it for me. I just told him that I want one with 2,200-2,400 stall and they got it. I'm pretty sure it is a reman tc as I dont see any decals or id on it. Just that it's grey,lol. Not funny but I should've made sure of that I guess. I just called a diff, shop that has a trans dyno. might just take it there today, $60 an hour but I'm TIRED of this. This is the 3rd time I've had this trans out and back in! 3 broken sprags before rebuild w borg sprag bearing. I was just hoping for a simple check/disconnect of the lockup noid. Thanks for the great info, more knowledge for the file. I'll post results once I decide/get them.

cahall

· #9 · Mar 6, 2013

The "rebuilt pump" part also concerns me. non PWM and PWM 4L60Es use different pumps as well as different lock up valves. I just had one in the shop around 6 months ago that another very popular transmission shop built that had a PWM pump in a '94 (non PWM) trans. It actually never operated correctly and locked the converter before it made it off the lift on initial install. I believe the fact that yours worked for 500 miles rules out this possibility though. BTW, that very popular transmission shop refused to fix this particular transmission under warranty because they claimed there was nothing they could have done to cause it to lock up immediately. They blamed it on his computer and left him out to hang.

Contact the shop that built it and see if they'll fix it. If not, I'll walk you through how to check everything.

Frank

cahall

· #10 · Mar 6, 2013

kzman78 said:
I just called a diff, shop that has a trans dyno. might just take it there today, $60 an hour but I'm TIRED of this. This is the 3rd time I've had this trans out and back in! 3 broken sprags before rebuild w borg sprag bearing. I was just hoping for a simple check/disconnect of the lockup noid. Thanks for the great info, more knowledge for the file. I'll post results once I decide/get them.

You shouldn't have to diagnose or fix this. Didn't you get a warranty with it? The shop that built it should be responsible.

Frank

kzman78

Discussion Starter · #11 · Mar 6, 2013

I've contacted the shop, they did the last sprag then the rebuild. There stand is that it has "high performance mods" (TCI servos and cluthes, kevlar band, BW one way bearing) and combined with the repairs, they believe it may be ABUSE why it keeps breaking and will not cover anything. I drive my car to work 80 miles a day(not every day tho, just when it's nice out) and have NEVER been to a track. MAYBE twice a month do I floor it from a stand still to spin the tires and chip second. Also, since rebuild, 1-2 shift is VERY quick, even before the lockup issue. Even at 1/4 thottle it will sometime chip into 2, but ALWAYS shifts quick!!!! 2-3 and 3-4 seem normal. Thx!

Dynamic396

· #12 · Mar 6, 2013

Wow... It appears that there is some really bad customer service out there...

I guess there are just a lot of shops that are just so busy, and just so profitable, that they can afford to tell a customer to screw off, citing "abuse" as the reason for failure (which is, by the way, the oldest, and lamest reason to deny warranty coverage).

Have I ever built someone a transmission that failed for a reason outside of my control? No doubt about it... (If you say you haven't, you're either lying, or you haven't built transmissions for very long...) Do I just tell the customer to screw off, citing "abuse" or blaming the rest of the vehicle? Not on your life...!

The answer ALWAYS lies in finding the root cause of the problem. As painful (and expensive) as it can be at times, good customer service will either help the customer find the cause of the failure or, as is my preference, get the whole vehicle to my shop and get to the bottom of it myself. If it's my fault, it's on me, and with my sincerest apologies... If it's something elsewhere in the vehicle that is the cause, once you have definitive proof of the fault, it's pretty easy to say "here it is...this wasn't my fault, but it's fixed now". Almost without fail, a conscientious customer will insist on paying me for my time in finding it...

I recently warrantied a 700R4 that I had built 2-1/2 years prior for the nicest old guy you'll ever want to meet. His 3-4 clutch had started to slip, and finally died. Puzzled and concerned about the failure, I told him to get it to me as soon as possible so I could take a look. He got the truck to my shop and after quizzing him a bit about his usage of the pickup, he mentioned that he had been hauling some "scrap" with the truck. A little more questioning revealed that every Friday afternoon for that entire 2-1/2 year period, he had hauled a flat-bed trailer, loaded with 18,000 lbs of metal scrap from Republic, WA to Ellensburg, WA (which is some of the most mountainous terrain in the state of WA)...with a 1/2 ton pickup equipped with a TBI 350 and a 700R4. That's about as clear-cut a case of abuse as you can ever get! Did I tell him to pound sand? Nope... Not in my small market. I warrantied it for him... And, after explaining to him the designed usage of a 700R4, yep, he insisted on paying me for my time...

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kzman78

Discussion Starter · #13 · Mar 9, 2013

Ok, here is what happened today. Went to the trans shop today and things aren't going so good. Mechanic hooks up scanner, goes to the trans readings. When he starts the car, while in park, everything reads normal. puts car in gear and after about 10 sec. the tc locks and stalls car. All sensor reading begin gliching or zero out, even the sensors that you can read on the engine side. BUT, when he backs out of trans side and switchs to engine readings,without resetting or restarting, the engine side shows all the correct sensor readings and that there all working properly. Then switchs back to trans side and all are still showing glitches. We tried a different working PCM and had all the same results thus ruling it out. He thinks it is going to be a wiring problem now. Any other thoughts or ideas?
Oh, Frank, he did try disconnecting the trans. Car would not start with it disconnected, had to start, disconnect, then shift. NO tc lock up!

cahall

· #14 · Mar 9, 2013

Drop the pan and check internal wiring harness.

Frank

kzman78

Discussion Starter · #15 · Mar 14, 2013

Thanks for all your help and tech support Frank!!!!! So far, I haven't heard any more from the shop since I call them back. He did remove the ground at PCM and had lock up. Still showing over volt code, 51 PCM code, and EGR fault. Has anybody else ever had issues like this with the computer showing that ALL sensors are bouncing all over or just zeroing out? I'm running out of options here and going broke!!!!!!!!

cahall

· #16 · Mar 14, 2013

Let me know what they find. I'm still betting it's something grounded inside the transmission.

Frank

kzman78

Discussion Starter · #17 · Mar 16, 2013

You got it! The lock up seliniod was bad. There was also a bad ground causing the glitching. So now it is done! Now I just have to find somewhere to have my pcm/ecm reprogrammed to remove some code stuff. Thanks again!!!

cahall

· #18 · Mar 16, 2013

Glad I could help. It would have been nice if your shop had dropped the pan first, instead of milking your wallet before they did.

Frank

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