TH 400 Shifting problems??????
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

SOUNDS LIKE A TORQUE CONVERTER

what causes a converter to go bad? I've got a good cooling system on the tranny and it was supposed to be new when the tranny we rebuilt.

any other ideas before I tear it apart?????????/

Thanks
Jason

BTW, I've checked the vacuum lines and they all seem good. They are not even a year old. How much vacuum should there be to make an auto tranny shift correctly?

Thanks for ANY help or input.

Thanks
Jason

I know you said you checked. But check the vacuume lines again. It is absolutly a vacuume prob. It will make it shift late. Around 3500 to 4000 rpms.

Also ck the pickup in the pan mine came loose and would suck air