Chevy Van 1975 Hydra-matic transmission problem

Mar 03, 2004 3 Replies

Chevy Van 1975 G10 series, 350 V8, with hydra-matic transmission. At start-up the transmission will not shift into any of the fwd drive gears. It will shift into reverse gear okay. Fluid level high after adding TransX additive. The transmission function okay the last time I drove it, except it took a few seconds shifting to get it working at start-up. Does any one have suggestions on how to fix this problem? Also, the engine will not start when in neutral gear; only when in park. Could the neutral start switch cause my problem with the transmission? Any help will be greatly appreciated.


Most likely its shrunken seals allowing too much fluid to escape past the clutch piston seals, until the seals warm enough to soften and "grip" the walls and seal. I had a Torqueflite that would do that a few years ago- it was a '66 model and had the problem in 1996. When I pulled it apart, the rear clutch rubber seal rings were about the texture of un-cooked pasta :-p

Nope.

Could a bad vacuum modulator valve keep the transmission from shifting into any of the fwd gears but allow it to shift to the reverse gear? Any suggestion? Thaank You.

No. The modulator affects upshift/downshift behavior, not into-gear behavior.

DS

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