Packard Forum Index » Post-War (1946-54)

So has anyone here ever rebuilt their own Ultramatic transmission??

John

Yes, using Kanters kit and other parts. Not terribly difficult but does require some attention to detail and some special tools to pull and replace some of the bushings. If a 55 or 6 you may have to use some ingenuity or make a tool or two to duplicate a factory tool used to hold or remove the springs in a couple of places. Biggest issue is to inspect and replace things that looks worn. The unit is dependent on bushings and shafts having the proper clearances so any wear on either and the pressures are impacted.

Check out my blog. I rebuilt mine.

I'd guess hundreds of folks have rebuilt their Ultramatics with results varying between excellent and terrible depending on how meticulous and thoroughly researched the effort was. If one thinks he can just buy a kit and replace the seals, gaskets and friction parts, chances are good he will be hugely disappointed.

I have 55's and 56's in stock and all special tools to do it correct. Agree with Owen D not overly difficult, but again it is a different kind of animal. Most that I get in are do it your self gone wrong, and those taken to modern transmission shops that say yes we can do it.

If you attempted yourself follow the book word for word and do not deviate.

Good general advice, Troy, but there are some places where deviation should be considered. For one, certainly the elimination of and substitution parts for the '56 converter wave washer. And I'd take advantage of improved redesign and metallurgy available for the parking pawl links.

There are two updates for two speed valve body - removal of an accumulator spring and a new shift valve spring to consider. Otherwise the unit may flare rather than shift to torque converter during acceleration.

Hello all, From my experience of working on Ultramatics and Twin Ultramatics over the past 30 years, I would strongly recommend that the input shaft should be hard chromed and ground back to size if there is any wear evident at all in the areas in contact with bushes. Looking at the wire brushed 56J shaft on Troy's Workshop, I would definitely have that shaft reconditioned before I would consider using it.
Also be very fussy about putting the new sealing ring on the Converter, make sure that you remove every trace of the old O ring or it will leak and drive you crazy.....from my experience.

Best regards, Peter Toet.

Thanks it does seem like a lot of good information. I had always heard with any rebuilding of an automatic transmission, cleanliness was the big thing to success.

John