first transmission rebuild

[86chevyk20]

So the pump is on its way out on my th400. 86 k20. Iv rebuild engines before but not a transmission. But i am thinking of taking a shot at rebuilding the th400.
Two questions:

1. can i get away just changing the pump if the fluid and filter are not trashed?
2. if i have to rebuild it.. what can i expect, how hard is it to do for a first time?

Thanks

Liam

 

[PrairieDrifter]

I personally hate rebuilding automatic trannies, I can do an engine and transfer case but I just send my transmissions out I can get one rebuilt for like 600 bucks around here. I can't stand doing them that's just me though

 

[HotRodPC]

Yes, if you are certain, it's just the pump, pull it apart, clean it up, new pump gears, new sealing rings, O ring and gasket, and put it back together.

If you're rebuilding it, here's what you can expect. Except not as much carnage. This one was toasted pretty bad. About the worst I've seen right here for a Turbo 400. This was in my 86. I bought the truck this way for $100 with a newer crate 454 in it.

http://www.gmsquarebody.com/forum/showthread.php?t=295