3.1 Hard downshift into first

[hermannm]

I have a 1992 cutlass supreme. I blew the head gasket on the engine and had to replace the whole enigne. Now everything runs fine execpt it shifts really hard into first gear. It never did this before. I have tried adjusting the TV cable but an unsure of how to properly do this. It shifted fine for a while and then started shifting hard. It upshifts fine. After it gets warm it will normally downshift fine into first gear as well. Any ideas as to what causes this?

On a seperate note my AC compressor wont cycle. It just keeps running. Is this bad for the compressor?

[bszopi]

The tranny should have a vacuum modulator (I think), so see if the vacuum line came off. That would cause the tranny to shift hard.

[3400-95-Modified]

3t40's shouldnt have a vac modulator that I know of...

[hermannm]

Yes it does have a vacuum modulator and i have checked that. I can adjust the TV cable and that seems to help but then the transmission doesnt shift at the proper shift points. Revs higher then it should normally at slow speed before shifting.

[gpse3400]

The A/C compressor equipped with these engine do not cycle, it is a variable displacement and changes its displacement based on system demand. The clutch wil always be engaged unless the unit is not selected or the pressure is too high.

The only thing that would really cause a harsh Park to Drive engagement would be the modulator. I'd take it out and see if any transmission fluid comes out of the vacuum port

[torq455]

park to drive engagement bang can be caused by a broken motor mount. adjusting the TV cable so that the shifts are higher will increase the line pressure. push the button and, while holding the cable casing, pull the casing away from the button. then, slowly push the gas pedal to the floor. you should hear what sounds like a zip-tie being tightened. TV cable is now set.

[hermannm]

Fixed the car today. It was the vacuum line that goes to the modulator. The screw was loose at the intake manifold and the rubber was cracked. Replaced rubber and tightened nut. All is well now. Thanks for the help!!!

[torq455]

right on!!!!

[gpse3400]

park to drive engagement bang can be caused by a broken motor mount. adjusting the TV cable so that the shifts are higher will increase the line pressure. push the button and, while holding the cable casing, pull the casing away from the button. then, slowly push the gas pedal to the floor. you should hear what sounds like a zip-tie being tightened. TV cable is now set.

The TV cable on a 440T4/4T60 only handles shift points, not shift quality.

The TV is typically pulled out a few extra clicks over the normal setting on some 440T4's/4T60's to get the shift point lower, as it seems to rise with age.

[torq455]

ohhhhh duh! i forgot all about the vac modulator! i'm pretty sure that when the throttle opens more, it pulls the cable out correct? if so, then the cable gets longer and the shifts are delayed. more throttle = higher shifts.