Turbo 400 upshift problem

[Boiler_81]

I am having a problem with upshifts with my Turbo 400 in a 1970 W30.

Background:

1.) The car was in storage for 5 years, I do not recall the issue prior to storage

2.) Car was removed from storage and test driven, under full throttle it seemed as if the transmission was shifting late. The tach does not work so I don?t know the shift RPM. However, acceleration was dropping off when it shifted.

3.) I checked the fluid level and found it to be a quart low and topped it off. In the next test drive the transmission would not shift at all under full throttle conditions. It did shift correctly under partial throttle.

4.) After the car sat for an hour I drove it again and got the late shift condition again.

Any Ideas?

Thanks,

Scott

[rocketraider]

Change the fluid and filter. You may even want to take it to a shop that has a Bilstein flushing machine and have the whole shebang flushed. I think what has happened is that during storage, all the fluid drained back to the pan and seeped out around the pan gasket (explains the quart low), and the remaining fluid film varnished on the transmission internals. The governor is probably sticking a little causing the late or no shifts, or the downshift solenoid or switch could have stuck too and caused the no upshift.

The salvation here is that transmission fluid is also a fairly decent solvent and will probably dissolve the goo eventually. It may take more than one cycle of flushing and driving to straighten it out. At worst you're looking at a transmission rebuild, and most any shop can do a Turbo 400.

[Oldsmaniac]

Check for a leaking or disconnected vacuum line that goes down to the modulator on the trans on the passenger side.

[Boiler_81]

Thanks Glenn! I will give your suggestion a try.

Scott

[Boiler_81]

Thanks, Oldsmaniac! I had done a quick look at the modulator line and saw nothing. I'll check it closer Monday.

Thanks,

Scott

[Boiler_81]

Glenn:

I think your theory may have been correct. I drove the car again to day and the upshifts under full throttle worked correctly.

Thanks,

Scott