So ive been haunted by the good old 3-4th clutch burnup in my 4l60e once again, i was driving the car in down and when it went to shift to 3rd there was nothing there just revved up like it was in neutral, ive had this happen befor and just assumed that the 3-4th clutch burnt up but the next day i went to move the car from my girlfriends to my fathers garage and on the way there like before no third gear as expected but then once a car pulled into a road and i began to accelerate again with the car in drive it majicaly had third gear again it felt sorta spongy but it was there so i slowed down again ad began to accelerate once again it took third and into OD no problem, and randomly sometimes it won't it just reves up like its in neutral durring the 2-3rd shift, anyone ever had this issue before ? what ever is causing this has obviously caused clutch damage anyway by the look and smell of the fluid but it just seems strange that this phantom 3rd gear randomly comes and goes.

 

A 1-2-neutral shift is usually a definite sign of 3-4 clutch failure. What you may be experiencing is just that there may be enough of them left to hold at some times, but not others.

Frank
CPT

 

But when it does shift to third its shifts firm, and the other times when it doesn't it just revs up like the clutches are gone, i duno, but this is the 3rd time that the 3-4th clutches have gone out of this car and in two different trannys, both were build by magnum transmissions with clutch savers shift kits and corvette servos and this transmission only has about 650 miles on it.

 

Um...It sounds like you might want to consider another transmission builder. You've obviously got some internal issues, if the fluid is discolored.
The Corvette servo isn't the best way to go. I'm not familiar with what a "clutch savers shift kit" is???

Frank
CPT

 

Other than the corvette servos what would you recommend to use, and sorry i should have worded that better it was the trans go shift kit, ive had transmissions built by other ppl as well as just stock ones, ive also had various torque converters in the car as well as computers. Being that the trannys pressures are controlled by the computer do you thing there may be an issue somewhere between the computer and the tranny causing the intermittent loss of third?

 

Depending on what parts they used out of the TG kit, some may actually contribute to premature 3-4 clutch failure.
There are many areas we devote specifically to keeping the 3-4's alive.
Are you certain the convereter is locking up? The 3-4 clutches need lock-up to keep them cool.
I can't see anything computer-wise that will cause an intermittant 3rd gear.

Frank
CPT

 

The converter seems to be locking up but this is also my frist time using a 3000 stall converter so im not real familiar with the feel, the car has a set of 3.73 rear end gears and on the highway it revs about 2500 rpm at 110 kmh, does this seem right. The computer was tunes by PCM for less and they were also sapose to tune the computer for the new stall speed. i also have a trans temp gauge in the car on the highway it runs about 200 and in town on a hot day about 230 ish does this seem normal?

 

the car is still having the same issue, and before i take it out id like to diagnose it a little first, i realize that damage has already been done but if i rebuild it its just gonna be the same story in 2 weeks, my question is with the GM tech scan tool when it shows TC lock up is that just displaying that the signal is being sent to lock up or does that mean it has actual done so? and with a problem like this do you have any areas that i could pay attention to when its apart, or could it be an internal elec problem or solenoid issue? thanx for your posts