1992 LT1 problems with auto tranny

[wulf]

My 92 Z07 C4 with 3.07 rear axle shows a few shifting abnormalities:
1. From gear 1-2 with floored gas, the tranny shifts to 2nd but back to 1 again. This sometimes repeats itself 2-3 times before the tranny decides to shift to 2.
If I do not completely floor the gas pedal but just prevent to touch the kickdown button there is no shift problem. Is the kickdown button responsible?
2. Driving in D (not OD) at around 3000 rpm or more and lifting the gas pedal I would expect the motor break to sart. This does sometimes not happen and the rpms decrease to idle ... If I then give gas again, the tranny seems to "rethink",
and the rpms increase again to 3000 rpm. Driving in OD, the "motor break" function is working as normal.
3. Shift point 1-2 is at the redline while 3-4 is at 4500 rpm. Why that?

Any ideas?

 

[wulf]

No experts out there? wulf

 

[White LT1]

92 Auto slipping 1 to 2 under full power

Same problem here. Alldata.com list some service buletins with the AT. When my trany fluid is cool the 1 to 2 shift problem is not present. Don't know when I first experance this but I think it was after I changed the filter/fluid. Fluid is Mobil synthetic. Maybe got the wrong filter.

 

[garycr14]

Tranny Problems

Sounds to me like you've lost your tranny. I just had to have mine rebuilt, clutches all gone, but that wasn't the real problem, just the symptom. Turns out that an internal piston (or what they call a piston, doesn't resembel one at all) had a hairline crack. It apparently expanded when warm & under pressure, and didn't want to kick into 2nd. I would drop the pan & check the band, if loose you'll need to rebuild. If not it is probably a computer problem.

The good news in all of this was I got to upgrade to a 2500 torque converter which makes a big difference on the launch.