Re: Ultramatic Rebuild for a '51

Posted by Ross On 2015/10/6 19:11:48

Except as a fascinating exercise I would not rebuild an extra trans when you could take care of the leaks on your existing trans with about $50 of seals and o-rings...

The direct drive clutches generally do not show any appreciable wear. They do however become hard as rocks and thus do not grip well. You should be able to sink your fingernail a bit into the surface. The bands are very hard and do not show much wear except where there has been a sticking servo. If you can bring them into standard adjustment without running out of threads on the adjusters they should be fine. Replace the high clutch disks as a matter of course as they are quite cheap, and actually are included in the rebuild kit. No need to replace the steels unless they have been burned.

Be certain that there is no more than .004 inch clearance between any bush and shaft. Factory clearance was .003". Be certain to replace the 3 lip seals in each servo as a lot of pressure can be lost there. The high clutch has a piston ring, not a lip seal in 49-mid 54 trans. Still nice to get in there to clean out debris.

I abandoned the use of the adjusting micrometer long ago and use the technique described for the end play in 55-56 Ultras instead. Much easier. Save some hassle and check it before you tear the trans down.

Of course, I would be delighted out of my skull to sell you my micrometer for only $200.........