The Stovebolt Site Forums The Shop Area Driveline HO 52 Spacer question

I'm putting together my 4:10 HO52 - replaced differential bearings, etc..

I pulled the pumpkin apart last year and was careful to store the parts. In factory diagram it is showing a spacer between the pinion flange and the outer pinion bearing (Rear axle 4-14, Fig 27, part 5 spacer) and I don't have one. The spacer between the bearings is there. I just took apart the 52 4:57 I have and it does not have the spacer either - the inner surface of the pinon flange was riding right up against the outer pinion bearing.

Is there a phantom spacer described in the manual? Anyone ever run up against this?

I'm planning to lube the pinion bearings with motor oil and RTV on the seal cover as well.

Also call pinion cruch sleeve, limits pinion brearing pre-load. Needs to be their or may damage bearings by being too tight. If don't have a new one you can add a shim or 2 and give the old one some room to 'crush'.

The crush sleeve is the one that fits between the bearings. There probably won't be a spacer between the pinion flange and the front pinion bearing cone. The crush sleeve is a one-time use item, so it might be necessary to procure a new one if you're reassembling a rear end with used parts. I hope you checked the tooth contact pattern before disassembly, as it's possible to build in a gear noise unless you get lucky and assemble the gears in exactly the same relationship as they came apart.
Jerry

I'm hoping I get lucky LOL..actually bro in law is a truck mechanic and is helping as well.

I'm thinking that spacer is not there...I understand the importance of having a matched one between both pinion bearings.

Gonna pull a third Eaton pumpkin apart later today to have a look.

Hy mapleleaf, your rear axle does not use a crush sleeve,as it employs a back-to-back front pinion bearing, this bearing set uses a precision spacer between the bearings and is always replaced as a unit. I see the spacer you are wondering about in the exploded diagram, I would say if it was assembled and functioning previously without a spacer, then the spacer in the diagram, may be a mistake, or perhaps the pinion yoke was made longer to make up for the missing spacer, ask your brother-in-law to confirm, hope that helps.

Well the mystery continues, HO52 #3 has the spacer and it is huge...3/16 thick and 2 and 11/16 across..

I can tell by the contact pattern on the outer bearing faces of the first 2 pumpkins that the spacer was not there..the contact pattern on them is the same size as the pinion flange yoke.

I measured the three pinion flanges and they are very close to the same length, maybe off less than a 16th.

Odd...I do have a 4th HO52 but not sure what tearing this down would prove.

I wonder what role this spacer plays?

Well..I think I figured it out..looks like there was a design change in the HO52 somewhere along the line, I'm guessing from 1949 (my original HO52) to 1952/53

The oil seal retainer on the "older" design is quite different from the "newer" design. The older one (part 3682199 - hard to read) is on the left, while the newer one (3848067) is on the right. The newer one has a far different lip that the yoke dust sleeve goes over and is much thinner than the older seal retainer plate. The dust shields on the yokes themselves are very different between the 2 designs as well.

Comp 1

the flip side of the 2 retainers is very different as well. The newer design has a raised lip that fits in against a recessed pinion race while the older style is flat across on the back.

Comp 2

So, there are also 2 distinct HO52 differential cases, the older style (3699585) in which the pinion race sits flat against the case surface..

older case

and the newer style (3934635) with recessed pinion bearing race

newer case

So, the spacer takes up the extra height of the "older" style pinion seal retainer, without it the dust shield on the yoke will bottom out against the shoulder of the seal retainer - the spacer provides the extra clearance when torquing the yoke down.

More trivial fun stovebolt facts.