Engine/Transmission (1994 - 1998) auto trans question

[Piersol]

I have a 1996 with the auto trans. 103,000 miles but the transmission was completely rebuilt at 74,000 miles. It works great except for, when under moderate acceleration in third gear at about 2,000 rpm it shoots in and out of lock up. Otherwise it shifts fine. My guess is the lock up solenoid or TPS. Any thoughts? Where is the lock up soleniod and how hard is it to replace?

 

[Joe G.]

The TPS controls the lockup solenoid via a signal to the CPM. I really doubt that the solenoid is bad. The first thing to try is to hose down the TPS with contact cleaner and work the throttle linkage back forth while you do it. That works for me. If it does not work then pull the wires from the TPS out of the bundle so they are loose and see if that helps. It that does then it is noise from dirt and/or corrosion in the TPS. A neater way to fix the noise problem is to install a capacitor on the TPS wires rather than just let them hang loose. Use the search to find an earlier post that gives the exact value of the capacitor to be used. I don't have the value handy.

 

[RVPILOT]

I had this problem on my 96 while still under warranty, the stealer tried to fix the problem after several attemts but was unsucessful. they replaced the tran with a new unit at 20k miles. the replaced unit finally went out at about 260k. got a DTT

 

[Piersol]

Rvpilot, Posts like that won't let me enjoy my weekend buddy!



:--)

 

[shendren]

there are many threads on this. .



this seems to be a common problem... i experienced it at 50k mi. some say to spray the tps liberally with contact cleaner. i did this many times and it did not help... ... .



I changed out the solenoid / temp sensor/ and 2 tps'... ..... the only way to fix mine was to TAKE THE WIRES GOING TO THE TPS OUT OF THE HARNESS!! PULL THEM OUT ABOUT 2 FEET BACK FROM THE TPS AND PUT THEM IN THEIR OWN WIRE LOOM..... PROBLEM SOLVED!! (electrical NOISE!!)



i have used every capacitor in every location... ... no fix. THERE IS NOTHING WRONG WITH PULLING YOUR TPS WIRES OUT OF THE MAIN HARNESS. JUST PUT THEM IN THEIR OWN LOOM. PROBLEM FIXED.

 

[jimk]

tps switch

Originally posted by shendren

there are many threads on this. .



this seems to be a common problem... i experienced it at 50k mi. some say to spray the tps liberally with contact cleaner. i did this many times and it did not help... ... .



I changed out the solenoid / temp sensor/ and 2 tps'... ..... the only way to fix mine was to TAKE THE WIRES GOING TO THE TPS OUT OF THE HARNESS!! PULL THEM OUT ABOUT 2 FEET BACK FROM THE TPS AND PUT THEM IN THEIR OWN WIRE LOOM..... PROBLEM SOLVED!! (electrical NOISE!!)



i have used every capacitor in every location... ... no fix. THERE IS NOTHING WRONG WITH PULLING YOUR TPS WIRES OUT OF THE MAIN HARNESS. JUST PUT THEM IN THEIR OWN LOOM. PROBLEM FIXED.

Today I had a the converter lock and unlock a couple of times at first in 3 gear while I was pulling my trailer. With a articulating four wheel drive loader and back hole on the trailer that weights several thousand pounds I was not happy. I stopped the truck and sprayed the switch with contact cleaner and still the the converter came unlocked. I used the lockup switch that I never use anymore and at least that stopped the problem.

I will try to pull the wires out of the loom as you suggest as I am tired of a unreliable transmission. If I ever get finished with the house and building a new shop I will never, ever,own a automatic. I am not racing my truck, just using it to work.

JimK

 

[Piersol]

Well, as I was pulling the wires for the tps sensor out of their loom I was saying to myself "this is a waste of time, this can't be the problem. " I was gladly wrong because my problem seems to be solved. Drove it 2 days now without a problem. You would think it would do this straight from the factory. The wires don't move over time.

 

[Joe G.]

What happens is that the inside gets dirty and probably corrodes. That's why many times contact cleaner will fix it. If that doesn't work then you have to deal with the cross talk between the wires caused by the poor contact. The TPS is almost impossible to open, clean, and reseal. My first TPS (before I knew diddley squat about them) caused a hammering jerk of the whole truck pulling a hill that was just the right grade. That finally wrecked the flex plate. It gave up quite a few miles after the dealer replaced the TPS (under warrantee), but the damage was caused by it. The mechanic said it tested fine using a volt meter, but it looked "ratty" on the scope. That TPS was replaced 160K miles ago. Everytime I change oil I give this one a shot of contact cleaner and work the linkage back and forth. No problems at all with this one. It appears that in this case a little PM goes a long way.

 

[Piersol]

This is probably a dumb question but when you guys talk about spraying the TPS with contact cleaner are you saying take it apart or just spray the outside or what?

 

[illflem]

Just spray it where the shaft from the throttle enters, enough will work it's way in. Mine use to hunt between gears also but that was 160k miles ago. Never replaced the stock tps with the same service as Joe's.

 

[shendren]

no one could help me with my problem and i spent a lot replacing parts. bill kondolay told me to pull the wires out and i finally did. glad it worked for someone else too.