After searching with no results I have a question for the TH400 gods.

I have a TH400 behind a Vortec 5.7 with a 205 t-case in an '84 1 Ton crew cab.

The tranny was totally gone through 6+months ago and this past weekend it started shifting sparatically. It wants to rev to about 3500 RPM before finally shifting. I replaced the modulator on the side of the tranny last night to no avail. Anyone have any ideas. Is this a vacuum problem to the modulator? Is the tranny junk? What can I do?

HELP!!

Thanks,
Jason:(

First thing to check would be the Vac. supply to the Modulator. The govenor might be acting up also.

If you replaced the modulator, that probably rules it out. Double check the vacuum line and routing to make sure there are no leaks. The next thing would be the governor. Pull of the 4 bolt cover at the rear of the tranny and pull out the governor. Check to see if the teeth on the governor are shreded or not. If chewed on or missing, THATS IT :).