'55 Conestoga Front Brakes and Rear Axle

[Spamcan]

Well, it's been near 2.5 years since my last post about my Conney and the rear end (Dana 44 3.31). The engine is in and Neil and I are slowly getting through the list of tasks. Long story short, the first shop failed me so I took the car back, Neil took the engine and re-rebuilt it. And come to find now that the 1st shop that also swapped out the Dana 44 3.92 for the Dana 44 3.31 I bought from StudeRich, failed me (again). They apparently didn't do a complete re-seal like I asked, or failed to do it correctly. I'm now under the car pulling the pumpkin off due to a leak, and as I got into prying the cover off, I now see that the leak (or another leak) seems to also be coming from the pinion shaft seal (where the drive shaft connects). I've been doing Google-fu searches and seems there's no consistency of what seal to use, be it a Spicer, Yukon or other. And watching YouTube videos, it seems to not be too bad of a job, just not something that I wanted yet another thing to do. Cleaning off the cover was bad enough, I'm only about 1/8th the way on the housing side trying to scrape off the RTV and fiber gasket - not easy laying under the car.

Am I seeing this picture correctly, that it seems to be leaking from the pinion seal?
Which seal should I use?
Worth doing myself? Special tools or considerations?
Once done, what is the preferred oil? More Google-fu comes back all over from 75w-90 to 80w-140, and synthetic or dino.

[StudeRich]

Welcome back David !

YouTube, Google, Facebook etc. etc. will do nothing but get you confused, hundreds of posts here about those issues would be more help from people who actually OWN a Studebaker or two.

The important thing about Rear Axle Oil is the GL Rating, you want GL-5, I stay away from any with multiple Grades.
The weight can be 85/90 or 90 as original recommendation.

Dino Gear Oil is fine. If it is a Limited Slip (Twin Traction) a 4 Oz. bottle of Friction Modifier, limited slip additive is recommended on a full drain.

The "Seal" is a Pinion Seal for a Dana Model 44, so neither Spicer or Yukon are needed, it is Studebaker Part Number 199379X1.
A NAPA # "NOS 15788" Pinion Seal will work.

It is not a hard Job, but you will need a Crow Bar or a Axle Flange holding tool.
You may be able to rent one from a Auto Parts Store to lock the Axle Flange to the floor from turning, while you unscrew the Flange Nut which is quite tight.

https://www.napaonline.com/en/p/NOS15788?ir=4&r-src=BR:PDP:SP:Belowproductdescription&ppid=NOS12577

[Spamcan]

Thank you Rich. As always you’re a wealth of knowledge. I don’t know if this is a limited slip model, maybe your son recalls? It was his that I bought, correct? Or what do I look for to ID if it is or not?

So the crow bar or axle flange tool is to stop the pinion from spinning? I’ve got the car up on jack stands, but the rear is by the frame so the axle hangs down to access the pumpkin. The wheels are on the ground and should stop the spin, though I do have a crow bar.

I watched this video and it seems like there’s a metal cover on top of the seal. Do I need a replacement one of those too? Or the seal puller tool?

on a different video, a guy said to put RTV on the splines to stop oil from coming past them. True?

https://youtu.be/r3iq28GkWpA?si=EPvnQbAp7vXrW-Nz

[Spamcan]

Cleanup of the cover and insides is done. Will get to the pinion seal at some point. Anything else I should do now before I seal the cover back up with permatex 2 along with the gasket? Or should I await to cover/seal after the pinion seal is done?

Actually, I’m using a LubeLocker gasket. Says I shouldn’t need the sealant. But with those grooves on the cover, I’m not certain that the red bead on the gasket will suffice and seal.

[StudeRich]

Your axle is a Standard axle, known as an "open" differential, you don't see a Twin Traction Clutch Pack in there, so not a TT.

I have never seen or heard of a LubeLocker Gasket for a Differential Cover, but it appears it was designed for a flat surface, I would not use it on that cover, a Standard FelPro Gasket will do fine, with your choice of Permatex types.

I would just hang that rear cover on there with a couple screws and no gasket, just to be safe in case of issues with the Pinion Seal install, it can't hurt to wait. Until you are ready for the Oil, there is no need.

[Dwight FitzSimons]

Because you already have the Lubelocker gasket you might use it with Permatex just on the cover side. I don't see how that wouldn't work well.

--Dwight

[Spamcan]

One thing I like about the LubeLocker gasket is it’s a sheet metal and rubber gasket. Supposedly reusable. So yea, maybe sealant only on the cover side. I reached out to LL to get their input/suggestions. They say it may work, but they’re wary of leaks since the silicon bands may not seal in the cover with those ridges not pressing and sealing up.

I’ve also pondered swapping out the cover with some other one that’s completely flat faced. Though could be tough with the way the brake line is mounted at the top of it.

I guess for assurances it’d be best and cheapest to just get a different gasket, like the FelPro as Rich suggested.

[StudeRich]

Good plan, the majority of differential leaks are not from the cover gasket, it is the Pinion Seal, as these parts get older and pile up the miles.

[Spamcan]

New gasket will be here tomorrow. At Napa I picked up the pinion seal, 10 quarts of Type-F trans fluid for the Flight-o-matic, 6 gallons of premixed “yellow” coolant, and 3 quarts of 80w-90 GL5. I can feel it, so close now if I’m considering adding the fluids.