I have a 65 Cutlass 330 4bll with the Jetaway trans and 3.23 rear axle. When floored from a stop it ***** hard into high at about 45 mph. If held in low it hits 65 at about 5000 rpm . Also it won't kick down when floored. The switch pitch seems to be working properly. I would like to shift into hi at 4500 to 5000 rpm at wot and have it kick down when floored below 55 mph or so. What do I check

 

Sounds like the kickdown switch isn't working. On my '68 (non switch pitch Jetaway), if I held the pedal to the floor hard enough to engage the downshift switch, it'd wind out until 70 MPH before it shifted (2.78 rear gear). If I floored it but didn't engage the switch, it would shift at around 55-60 MPH (didn't have a tach back then). Any time I stomped it (engaging the switch) when going less than ~65 MPH, it would downshift.

 

Mine was a vacuum line.

 

First check and make sure you have 12v at the transmission tab when the pedal is floored. If you don't like the shift points you'll need to modify the weights on the transmission governor.

 

If it shifts into high at 45 hard, it won't kick down into into first when you floor it at anything above that speed because you are already too fast for that low gear. Go see if it will kick down after it shifts to high at 30 or so.

If you want to change the shift points, that's not the kickdown switch.

 

As I remember my 66 f85 acted the same as Johnny B's. Eric is the trans tab you refer to on the throttle switch on the firewall?
I wouldn't think it should be "too fast" when you can manually hold it in low until 65 which is 5000 rpm.
It shifts down into low below 15 to 20 mph under moderate acceleration.

 

Yes, but the one I'm talking about is where that wire connects at the transmission.

 

Thx Eric I'll check that out.

 

I'm pretty sure the vacuum modulator on the Jetaway controls only the partial-throttle upshift point. Once it shifts to 2nd gear, the only way to get it to downshift is to stomp it hard enough to engage the downshift switch or pull the shifter back to "L" (at least that's how mine worked). Pushing the pedal to the floor without engaging the downshift switch would not cause it to downshift even if it was going only ~20 MPH in 2nd. Another peculiar behavior was that if I floored it from a stop w/ the shifter in "L" without engaging the downshift switch, if I moved the shifter from "L" to "D" it would force an upshift even if going only around 30 MPH (long before it would've naturally up-shifted if started in "D"). It was like the shift from "L" to "D" over-rode the vacuum modulator's natural upshift point. However, if I engaged the downshift switch, moving from "L" to "D" did nothing and it up-shifted at ~70 MPH as usual.

 

Sorry for not posting an update sooner. I hate it when an OP doesn't fallow up after asking a question.
Anyways I didn't get around to doing anything the about it until this spring. I ended up taking the kick down switch apart and discovered that the terminals were corroded. I cleaned them and took it for a drive. Success! Not only does it kick down but holds passing gear to slightly over 70 mph (5500 rpm) instead of the previous 45 mph. So obviously its not just the governor that controls when it up shifts.
Thanks for the help.

 

Thanks for the follow-up, glad you got it working correctly.