[Joe's Garage]

Originally Posted by 78w72

curious how the kick down solenoid would not let the trans shift into 3rd, or any gear for that matter? isnt it only for kickdown operation?

If the solenoid is energized or leaking so the transmission THINKS it's energized, the transmission WILL eventually shift, but it will shift as if the engine is at full throttle.

And it will shift with almost the same firmness you would experience at full throttle, as the modulator will only soften the shift a certain amount with that fluid circuit open.

So the shifts will be fairly crisp and will happen at maybe 40-50 and 80-90 MPH, depending on the rear gear ratio.

We stripped the hold-down threads on a shift solenoid on an old 1972 Grand Prix while installing a B&M Shift Kit about forty years ago and it performed just like this - pretty firm shifts at about 40 and 70. It was fun for about ten minutes and then we had to pull the transmission out to swap the case......

It's possible that 63 Pontiac is driving 'normally' and may not have gotten up to those speeds - yet.

Hopefully it's something easy to fix.

[78w72]

Originally Posted by Joe's Garage

If the solenoid is energized or leaking so the transmission THINKS it's energized, the transmission WILL eventually shift, but it will shift as if the engine is at full throttle.

And it will shift with almost the same firmness you would experience at full throttle, as the modulator will only soften the shift a certain amount with that fluid circuit open.

So the shifts will be fairly crisp and will happen at maybe 40-50 and 80-90 MPH, depending on the rear gear ratio.

We stripped the hold-down threads on a shift solenoid on an old 1972 Grand Prix while installing a B&M Shift Kit about forty years ago and it performed just like this - pretty firm shifts at about 40 and 70. It was fun for about ten minutes and then we had to pull the transmission out to swap the case......

It's possible that 63 Pontiac is driving 'normally' and may not have gotten up to those speeds - yet.

Hopefully it's something easy to fix.

thanks for the explanation, wasnt sure what you meant. i figured the solenoid would need the switch to become energized, never really looked at how the switch/solenoid works though.

but the car i mentioned with nothing connected to the solenoid shifted & acted normal. i owned it so long it actually had 2 different gear sets, i bought it with 2.56 (prev owner killed the original 3.42 rear) then when the engine was rebuilt i changed to 3.90 which were overkill but i didnt know at the time, the trans operated pretty normal for each gear ratio or mph shift points.

[Scott Thelander]

wazzzzzzz up ?

[63 Pontiac]

Ended up replacing the vacuum hose at the carb and it seems to be shifting properly. Need to drive some more around town and then get it on the highway.

[Schurkey]

So you just weren't driving hard enough to get it to shift???