T460-E 4-3 Downshifting

[Silent Jay]

I have a 94 Grand-Am 3.1 with a T460E. The tranny likes to downshift to 3rd from 4th if I let off the throttle, as soon as I get back on the throttle, it'll rev back up and go back into fourth. This will still happen if I do this going down a steep hill, so it's not like it's lacking any power. If I'm in 4th and going up a hill and don't let off the throttle, it'll stay in 4th and won't downshift unless it’s supposed to.

The shifts are very smooth and I’ve only noticed the problem if I keep my eyes on the tac. The check engine light has never came on.

I've replaced both shift solenoids and either the PWM solenoid or the TCC, can't remember. The dealership didn't have one of them in their computer, and I had to close up the tranny to get it back on the road. At the time I was confident that one the solenoids that I replaced was bad, and that the problem was solved. Blah.

[IsaacHayes]

What you are feeling is the TCC disengaging. As far as I know that's normal. Mine has always done it. When you let off it disengages so it will coast. When you get back on the gas the RPMs go up (until you reach the stall speed of the TC) then it re-engages the TCC lock up which drops the RPMs back down which are of course lower because you don't have the stall speed on the TC slipping.

If you go on the highway and slowly press on the gas, you'll feel it kick out of TCC, then downshift to 3rd, then finally to 2nd. Note the RPMs.

Later years used a PWM TCC solenoid and you don't feel it engaging and disengaging. My friends 97 lumina you can not feel it.

Solution, keep light pressure on the throttle ever so slightly. No on/off pedal action.