The Stovebolt Site Forums The Shop Area Driveline rebuilding a 1954 differential

If a person was wanting to rebuild a 1954 Chevy 1/2 ton differential and was going to reuse the ring and pinion and the differential. Would you use the same procedures for setting up the gears as you would with a new gear set? What do they use instead of red lead for marking the gears for mesh?
i would like to washout and possibly replace the bearings in the differential. Don't ask me how someone did this but they installed the rear cover on the other way around and the ring gear was rubbing on the inside of the cover. So I want to make sure there are no metal filings in the assembly.
Thanks John

If your going to re-use the same ring and pinion make sure that you keep track of the shim or shims for the pinion so you can re-use the same. You can use white lithium to check the pattern or you can buy prussian blue paste from a tool supply store.

If I'm replacing the bearings on the pinion, do I need to re-figure the shim count then?? How much difference is there between the '54 rear end and the 1952 rear ends in settings? The shop manual I have covers up to 1951 with a suppliment for 1952 trucks.

John

John,

Here is the 1954 Shop Manual on-line.

I'd check that the original shims still give a good fit/"reading"

Hi Tim,

Yeah I don't know what kind of mileage was on this rear end. I bought it from a '54 truck in a salvage yard for my 1953 1/2 ton.
Thanks for the link. John

What bearings and bushings are you replacing, John?

Definitely measure the ring and pinion gap prior to disassembly. You want them to be reinstalled at this setting because they wear as a pair. If you reinstall to factory settings you'll end up with rear end noise and possible future damage.

I use white grease when setting up ring and pinions. The prussian blue is okay at best, I think it's crap myself, and is almost impossible for me to read on a new, unworn ring and pinion. White grease was the easiest for my eyes to decipher.

Jeff

rustednuts is right on. I just picked up my differential today after "monkeying" with my ring and pinion. I should have left the darn setting where it was. I ended up with "noise" so I let a good friend, who runs a 4X4 business and builds these suckers everyday, rebuid mine. I picked it up today with a new 3.38 and a complete overhaul kit. (bearings ect)
.....I think my friend uses some type valve lapping compound to check the pattern, but I think the gear folks send it with the gears.

Hi Tim,

Don't know which bearings I'll replace or not, mainly concerned about possible metal shaving being in some of the bearings. Hopefully not though. Or what was the reason for putting the cover on wrong way around. Was there a problem so they just stuck it back together, though it looks like it was run some by the look of the inside of the cover.
John

I had thought about the possibility of changing out to 3:55 ratio they have. Not sure if that might be to high for this area or not. i'm in SW PA, kind of hilly country. Though the truck as I got it low pressure 235 (car engine), original 4 speed granny gear transmission and 4:10 rear end with 6.50-16 tires on the back, seem to have pretty good lugging power on the hills. Usually once in high, it didn't need to be downshifted only on the long hills and at starts and stops. Never had to downshift below 3rd on any of them. Was getting around 14-15 mpg.
My thought were to go to the 3:90 and still use the 16" wheels, probably with 215 85R16 tires in place of the bias plies.

John

John, if your tearing the whole thing down, I would go ahead and just rebuild the entire assembly. Those bearings have been driving that rear end for 60+ years now. Why not go ahead and replace them while it's apart?

Also, if you get it all torn apart and get it degreased completely, you may be able to take it into a carwash and use the high pressure heated water for a final clean. Depends on the carwash/EPA, but when I rebuilt my '53 rear end, the pinion bearing had about 3 or 4 ball bearings left in it. The rest was metal paste smeared everywhere.

I scrubbed and degreased it so that eventually the water was free of oil residue than brought it to the carwash. I drove it around town for short trips, changing the oil every 2 weeks or so and stuck a huge magnet to the bottom of the axle housing. Rub the oil through your fingers when changing it and look for any silvery specks. When it's clean, your done!

Jeff

If you change the bearings on the pinion, where do you get a new rivet to reattach it to the drive shaft?

John

John, just about any of the vendors sell it, or at least they did. Not a rivet, but a pin.

Click!

Jeff

There is a misprint in that listing. The pin is 5/16".
I make my own out of 5/16" rod.

Is the pin a press fit or do you peen the ends over to secure it from working out?

John

The ends need to be peened over.
I replicate the factory install by deep center punching the ends to swell them than flatten the ends.

Okay thanks Dave.

John

This spacer tool that is shown in the shop manual for checking the clearance on the pinion gear (spacer tool J-4050). Do I need this for a rebuild if I'm reusing the same gears? The way I read the text it is only needed if installing and setting up a new pinion gear.

John

It's been several years since I rebuilt mine, but I do believe you need it. If I'm thinking correctly, it sets the pinion bearing in the proper place when you tighten down the three lock bolts in the case of the carrier/torque tube.

Jeff

If you do not use the spacer during installation the rear pinion bearing will not be forced far enough into the housing and it will wear on the front of the pinion gear. I don't remember with a 3.9 but some times you can use a punch between the teeth and drive the bearing forward.
Where are you located? I have a stack of the spacers. I could mail you one.
You could also make up a simple tool/spacer.

I have a J-4050 tool. Patrick's includes it with the 3.55 R&P installation kit. I'll loan it out to anyone after arranging (in a Private Message) for a refundable-deposit/shipping (sorry, but Hotrod Lincoln's sad experiences in loaning tools makes a deposit necessary).

I was wondering if a person could make one of these or not. I assume it has a certain thickness? Looks to be about 1/8" thickness......

John

I recently replace the ring and pinion in my '52. Upon disassembly, the ball retainer on the double row bearing was gone. So, obviously the pinion bearings got replaced. Upon careful inspection, the carrier bearings were in great shape. No perceptible wear, scoring, etc. I reused them as replacing them later is not a big deal as you don't have to mess with the depth of the pinion gear when removing the carrier. From my research, the pinion bearings are the most common failure point in the rear differential.

I figured I'd replace what bearings if any that needed replaced. if I don't see any discoloration, spalding ect... I'll reuse them. I figure the old USA made bearings are probably better made than the Chinese, Thailand,Pakastan bearings are anymore.....

John