I'm getting pretty good at swapping trannies on my back. This is the 10th I've done! Not this car though..

I'm posting here becaus of the lack of trans people on other sites, and the lack of a trans section, for that matter...

I recently bought a '94 Z28. Runs good, slightly modded, and before I got it (bought from a friend of mine), he burned up the factory 4L60-E. We had it rebuilt by the dealership by the foreman on the side, and after waiting for what seemed like forever, I got it back. Well I drove it for like 150 miles, it worked decent, then it just quit. One day at a red light it just started slipping like a mother in all gears, to the point that it would bearly even move. I took it back and he said a valve in the valve body was wallowed out, and rebuilt it again for me. I waitied another eternity...after getting the car back 2 months later, I drove it around a little, fixing the other things wrong with it. I gave the car back to my friend who owned it at the time, after I put 150 flawless miles on it and checked it every way an auto mechanic can, and the same damn thing happened. 2 days later, it burned up. He got fed up and sold me the car because he needed something reliable.

Before it self destructed AGAIN, I checked the solenoids, which were supposedly new, and I could hear them work inside the transmission. I checked current with a scantool and it went down to .16mA. It always shifted fine before it suddenly gave up, except it had a bit of a delay when upshifting and downshifting (not slippage). It has some kind of shift kit in it, although I don't know what kind...pretty crappy probably. When it blew up this time, I only lost the 3-4 clutch pack, as opposed to all forward gears. Reverse and over-run always worked ok. He looked funny driving home that one time backwards I went out and checked the fluid...it smells burnt slightly, but there is no residue either in the pan or on the dipstick, so I'm reluctant to drive it since I don't know if the clutches are done yet...it was drive home in second gear, 5 miles.

Anything sticking in your minds that would cause this problem? I'm thinking about buying a new valve body altogether with a transgo for a 4L60-E and seeing what that does for me. Supposedly all the internal parts were new, but now I'm skeptical to take it back to wait another eternity...somebody please help, if I can't fix it I'll sell it for core and drop in a T-56. Thanks a ton!

 

First off, I'd probably start by letting somebody else work on it. "Third times a charm" is not a good rule in auto mechanics.

You mentioned that the PC Solenoid could go down to .16 Amp, but thats only the commanded state. You need to hook up the line pressure gauge, and make sure that the pressures correspond to the commanded amperage. Start at 1.0 Amp, and work your way down from .90, .80, .70, .60 etc... and make sure that they all are within spec. (if you need a spec chart, let me know, I'll get you one). At .20 Amp, you should have well over 250 PSI. If not, you may have a bad solenoid or a pump problem.

 

If you could get me a schematic of some sort, that would be great. My biggest problem is that I no longer have access to a scantool, since I had to leave my job at where I worked for VERY low pay. I also have no idea where I can get a trans fluid pressure gage. Any other type of pressure gage work without ruining it? I thought there might be a fluid pressure problem, but I have no means I can see to verify it. I agree with you that I should get someone else to work on it...however, I am mechanically inclined so doing preliminary checks should not be a problem. Thanks for the reply!