MTFCA Forum

I want to run a re babbitted fourth main. What would you to repair these pits?

If they're not on the bearing surface, you can ignore them. If they're on the bearing surface, it would probably be best to replace the part. If the pits are not deep, the piece could be reground and a rebabbited bearing made to fit, but it might be cheaper to replace it.

Here is link to old post by Herm. Should be titled “Everything you wanted to know about T transmission, but was scared to Ask.”
https://mtfca.com/phpBB3/viewtopic.php?t=2114

If I HAD to re-use that, I would maybe consider JB weld. There is no real heat there. The good metal there will hold the weight, all you're trying to do is prevent leaks.

Or you could have someone turn it down a little and put a bronze sleeve on it.

You turn it in a lathe . Square & clean the surface to a minimum (90%) with a tool post grinder.
Have a 4th main machined to match. I do this with every transmission I rebuild. They all need a little resurface to take the worn areas out & give 100% bearing surface anyway. It usually takes a lot less material removal than it looks.

Flip it over and check the rivets for cracks. 9 out of 10 are cracked there.
Have been told someone is looking to make some new ones but will not be cheap.

Dan Hatch wrote: ↑

Wed Aug 24, 2022 11:12 am

Flip it over and check the rivets for cracks. 9 out of 10 are cracked there.
Have been told someone is looking to make some new ones but will not be cheap.

Make sure the rivets are tight. I like welding a 3/4-1" bead in 3 places, (between the 3 web holes).
[If the rivets were loose, there is an alignment issue. The pan is bent and/or the transmission output isnt running square.]
Then do square up cuts to the plate in a lathe to the mating surfaces.
The last step is the regrinding of that 4th main bearing surface.
A waysback I posted pictures of this operation.

P.S. DO NOT sand/bead blast this part. The abrasive will stay in the finger pivot pins & keep grinding away forever.