flewster

I just recently bought a 1994 1500 with a 5.7L motor and what I believe to be a 4L60E transmission. (have not gotten under to varify) Truck has 205,000 miles.

Problem is this. While at a stop sign the other day I started off and expierenced a shudder and then it took off. When it went to shift to second gear it just reved the engine. Pulled over and shut truck off. Re-started and it went just fine. A while later same thing. So back on the highway to get home. After a few miles it downshifted out of OD and started acting strange again. Shift to nuteral, turn off ignition, restart and fine for a few more miles. Then it started to loose all forward gears BUT I shift to neutral, turn off ingnition and then restart and be fine for a few more miles..........Spedometer does not act crazy or drop off during all of this...........funny that I can turn ignition off then restart and it acts fine for a while......

Any Ideas Please........Thank you......

flewster

Thinking back.....I did not have this problem until after I changed the Battery.......I changed it and I had a small contact spark but nothing major.......but it was after that, that this problem developed.......and then got progressivly worse..........PCM?

NUTZ

flewster - the symptoms you are describing are exactly what my transmission did before it went out, but turning the vehicle on and off didn't work for me so perhaps it is a computer problem - guess I wasn't much help

cams 98 silverado

first off. little transmission lesson. the reason why when tow trucks disconnect the driveshaft on rwd vehicles is because of bearings. if your motor is running. your turning either a vane or gear pump to circulate trans fluid throughout the many hydraulic circuits. it also pumps fluid to input and output bearings. now. with a motor not turning. and no fluid yet your wheels are turning. means your trans is going een though your in neutral. neutral is just seperating the motor energy from output energy. so. my first saying is never have a vehicle with an auto tranny moving with motor off. you can fry( depending on how bad the fluid is and bearing wear) your bearings. secondly. take it somewhere to get the codes read. its obdI so take it where theres a tool to read it. if its pcm controlled its a 4l60e. otherwise its vacuum controlled and it would be a 700r4. so... to me. my first gut feeling is maybe one of your solenoids is poopin out on you. its a shift solenoid. and if it is indeed that then its a moderately cheap part. less than a franklin. and all you do is drop the pan remove a jesus clip. e-clip and wiring clip then slide out old and in with new. let us know. and for the sake of bearings... dont drive with the motor off. only do that in manuals. they dont have a pump.

flewster

Thank you. So it is possible a solenoid could be causing this broblem?......since they are electronic it makes sense why removing power and restarting would make it OK for a while. Night before last I unhooked battery to reset computer. After 30 minutes reconnected and tried to go for a drive. Well, it went about a 1/4 mile then would not go.......no forward or reverse..........turned off and sat in the dark for a while then restarted and off I went.....got back to house and parked...........Now if this is setting a code will the check engine light come on? Because it didn't. And I have read that I can flash the codes like I can in my blazer by shorting two pins on the plug...........

flewster

Well, I just got around to this and replaced the 2-3 solenoid and the other one that is just like it.............truck runs fine now execpt for it does nt shift at WOT and it slipps a little in second gear...........will have to rebuild soon....

Mike37

I have a 1994 Chevy silverado the transmission would shift to overdrive before it was time an then overdrive jus quit working i can shift it up manually from 2nd gear an will shift like that Was told there was something you could tighten up a screw or something when u took the pan off is that true

Netherton.beverly@gmail.com

Yes you can pull the codes on OBD 1 by taking a paperclip or wire and jump the two inlets that have a silver diode in them. The codes will flash thru the check engine light. The first code is gonna be 12 read by 1 flashing light then a pause and the light flashing 2 times. This code is to let you know its reading and basically every is ok if there ar we no codes in the system.