VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 28 Diff rebuild

So i have clearly lost my senses and am going to rebuild a 27 and 28 diff, I do not have complete diffs to disassemble to see how they were put together, Bu t have to got all new bearings, new Billly Possum tail shaft and axels, Don't have a matched set of gears for the 28 so am going with a very good crown wheel and pinion and will lap them with valve grinding paste. My first shock was the bearings were metric in size, ie: the double row pinion thrust bearing is 25mm ID NOT 1", So were the sun wheel bearings ??? What is that about?

First question, how is the bush at the front of the torque tube located? There is a divet in the bush 1/4" wide by about the same depth but it is a rounded at the bottom of the hole and no thread or such in it. there is a larger 3/16" hole in the torque tube o line the hole up with but no other sign of what prevents the bush working loose and rotation with the tail shaft over time.

I have the handbook which runs through how to reset a diff but there is no exploded diagram of the components and the order the collar and washers go to gether at the pinion end, If someone has could they please post a pic or message me for my email. Ray

You can bring your old bearing to a local bearing supplier and they can match. Did it for my generator and got bearings for less then "Chevrolet" ones and no shipping or long waits. Wishing you well on your rebuild.

Yes that’s what I did, have the Remains of 3 diffs took in all the old bearings and got matches for the full set of bearings for all 3 diffs for $420. Thought that was pretty good. Though you have to specify that it’s a pressure situation you don’t want generic bearings that are used for trolleys etc they are cheap but nasty.
Couldn’t get the thin sintered brass bush for the front of the torque so had to put in an over size bush and machine down.

When I rebuilt mine I got my bearings through VXB (https://www.vxb.com/) which had very reasonably priced bearings, so far so good.

I did the same thing when I started taking everything apart regarding the metric sizes! It's interesting because the shop/spec manuals call out the bearing sizes in goofy inch measurements which made a lot more sense once I realized they were actually metric.

-Tyler

Morning all, so have assembled the shaft , bearings and gears , doing a dry run to asses alignment, I need the tool that you tighten the cage either side if the crown wheel bearing with. Is there anyone here in Sydney who could lend me one or tell me what it is called and where to get one please . Ray

Just make one up,with a long enough handle to turn the crownwheel carrier bearing adjust nuts to get the pre-load right,with an open "C" on the adjusting end and weld 2 small pins in it to fit neatly into the holes on the adjusting nuts.