350 Turbo with cracked case

[atarijake]

Hello, my 78 k10 (full time) blew the transmission(th350) the other day and now has a healthy crack that's spewing fluid everywhere.

I've called around a few places to get quotes on a used or re manufactured TH350, but I feel like there might be another problem that caused the crack in the first place. I did some research here on this forum and apparently there's a tendency for these to crack because of a lack of bracing from the factory?

Possibly also replacing all the engine and transfer case mounts? What other things could contribute to a cracked transmission case? I wasn't thrashing the truck at all when it happened, it was just cracked when I went out one morning.

The bed is seriously sagging on one side, I don't know if this could have caused any unusual stress on any of the mounts...

If I attempted to replace the transmission myself, it would definitely be largest repair job I've ever tackled, but I feel confident I could handle it. I just want to make sure I completely fix the problem when I get in there and not have another cracked case on my hands in 3 months because I didn't replace all the correct parts.

Thanks everybody!

[83burban]

I don't think it is a lack of bracing that would have caused your problem. Maybe you mount is damaged and that caused it to flex.

If you replace the mounts don;t mix and match rubber with urethane - they should all be the same. Just my .02 cents.

[atarijake]

Awesome, thanks!

[silvereagle07]

I just had this problem with my 7oor4. It seems to be a combination of the motor mounts and trans mount fatigue. I would check the motor mounts and trans mount when you are replacing the trans.