gaerte04

Hello all, I have a turbo 400 in my 70 442 that has issues with shifting from second to third gear. If I am tring to get on it it will shift from first to second no problem but when it tries to shift to third it wont shift till I let up on it, then it will shift. The previous owner of the car put a switch pitch in it and it runs off a timer box that he installed but I have taken the timmer off of it and it makes no difference on the shifting. Any help would be appreciated.

Thanks

oldcutlass

The switch pitch is an odd trans for most people to get a grasp on. It has a variable vane torque converter. It needs an electrical signal to switch back and forth and also works in conjunction with the passing gear. Is there a SP switch assy installed on the throttle linkage? It has 3 wires going to it, 1 is power in, 2 and 3 are outputs to the passing gear and SP prongs on the drivers side rear or the trans.

gaerte04

I will have to look this weekend my car is still in storage. Let me add that this car use to be set up for drag racing and I believe the timer box that I was talking about is attached to the break pedal because as soon as you let go of the break it counts down for three seconds and that is hen it is suppose to switch the vanes to the lower stall for faster speed. Like I said I have unplugged this and it seems to make no difference.

Rickman48

Could it have a broken governor spring??
Easily checked.

gaerte04

I will check the governor spring I did some reading on it and that sounds like a good possibility. I will also check on the wiring for the switch pitch and see what is going on with that. Thanks for the responses. With it being 70 and 80 degrees I think I will be getting the car out soon.

oldcutlass

Also check your vauum to and the modulator valve. I've seen them do really strange things. Pull the vauum line off and see if there is any trans fluid in it.

gaerte04

I got the car the other day and started looking at the electrical for the transmission. The transmission has a two prong connector on the driver side. I found that the brake pedal had a switch with one wire that went to the timer box and then the timer box went to the transmission. Also the gas pedal has a kick down switch with a wire going to the other prong on the transmission. How can I tell if it is truly a switch pitch or if the second prong is for a tcs switch that could have been on the car. there is not a SP switch on the throttle linkage like you had mentioned Oldscutlass the only thing that is powering the second prong is the timer. I am going to check the other two things that was mentioned tomorrow.

oldcutlass

If you think it's a TCS system read this thread. It has pics, and explains the operation of the system.


https://classicoldsmobile.com/forums...emissions.html