Engine/Transmission (1994 - 1998) 96 Trans issues

[KKitelinger]

I'm stumped, have a 96 that is kicking out of lock-up in drive and overdrive and also kicking out of overdrive itself, even if my lock-up switch is on. Tried a different TPS, tried the POT mod also, still the same. Truck did have a TCC solenoid code, replaced all solenoids and switches on the VB and still same thing. Just cleaned all grounds i could find under the hood and batt terminals also looked for any signs of wires rubbing through somewhere and nothing. Code cleared and nothing is coming up now when scanned. I am still leaning towards something electrical. Have not had time to get pressure readings yet, that is this weekend’s task. Any other ideas?

 

[cerberusiam]

Trans control relay is a possibility. The only way it is coming out of lockup and\or OD with a lockup switch is either loosing power the relays or pressure to the circuits. You might try the jumper wire on the relay to bypass it.



Is it intermittent or can you replicate the problem at will? Any common things contribute to it dropping lockup and\or OD?

 

[KKitelinger]

Already have a jumper in place of the relay, forgot to mention that. It started out intermittently, but is now pretty constant. In drive it will go into lock-up and then start locking and un-locking, if I have the lock-up switch on it is better until I let of the throttle and then it jumps in and out. When in overdrive once it kicks out then it won't go back into overdrive/lock-up unless I hit the lock-up switch to force it and then it will kick back out shortly after and then go in an out repeatedly until I undo the lock-up switch and then it will just hang in 3rd again.

 

[JLandry]

KK,

You say you've had all the solenoids replaced. Did that include the 3rd to 4th gear lockup solenoid? That one requires dropping the valve body to replace and it isn't as common a replacement as the governor pressure sensor and governor pressure solenoid. You can buy one online for around $50 plus shipping at transmissionpartsusa.com

John L.

 

[KKitelinger]

Yep, both solenoids, gov pressure sensor and temp sensor all replaced with new ones.

 

[JLandry]

You're in Iowa. Why not drive on over to Goerend in St. Lucas?



I'll bet they can figure out what's wrong pretty darn quick.



Just a thought.



John L.

 

[KKitelinger]

Dave is about 5hr from me, but unfourtantly there is no driving it at this point, it would have to be hauled if going very far.

 

[JLandry]

Pull that sick transmission out of your truck, throw it in the back of your '76 Ford Pinto, head over to Dave's, and swap it out for one of his beautiful heavy-duty transmissions.



You know you want to.



John L.

 

[cerberusiam]

Dave is about 5hr from me, but unfourtantly there is no driving it at this point, it would have to be hauled if going very far.

Have you called Dave and chatted with him? If you can get him on the phone he is great to talk to and might know off the top of his head where the issue is.

 

[KKitelinger]

Not yet, wanted to get pressure readings first so I have most of the info he would want/ask for.

 

[SFPADGETT]

Have you checked the brake light switch? It is is loose an "bumps" going down the road, the transmission will "unlock", if the pedal spring is a little worn and the pedal contacts the switch, the transmission will not re lock. The switch is cheap and easy to replace- just follow the directions in FM or the box the switch comes in. We have "cured" several transmission problems over the years by replacing the switch. We also had a problem with the "ground" feed wire from the transmissioin up to the CPU, the wire would ohm as good, but we replaced it and the transmission went back to working (details in one of my post's). Good luck

 

[KKitelinger]

Ended up finding a bad Output Speed Sensor in the trans was causing the issue. Thanks for all the info. SFPADGETT, the brake switch was one of the first things I checked, I have ran into issues with that before also.

 

[JLandry]

Wow!



All that trouble and it was just a $10 part.



I just assumed you had already replaced that because it's so cheap and easy. My bad!



John L.