The Stovebolt Site Forums The Shop Area Driveline What Seal (gasket or sealant) to use for Driveshaft to Rear Differential

1948 Chevrolet Pick-up (1/2 Ton) actually my chassis is off a 1951 truck; noticed I have a small leak on my rear differential, seems like it is coming from the Front, where the Driveshaft connects. Was just curious, is there a Gasket for this, or supposed to use sealant? If sealant, what type/brand of sealant is best, how large of a bead to run, what do folks on the forum recommend? Also, when I put everything back, what Ft Lbs of torque should I tighten the nuts to? Appreciate any insights!

If you have a rear end Like This.
And it is leaking at the upper 5.504 Carrier arrow.
Where the torque tube enters the cast carrier housing.
Leak at Left arrow, Torque tube to carrier housing connection. Picture
To rectify the leak some people have run a weld at the connection.
But I'm sure there is some kind if oil resistant sealant that would work also.

Thanks, that looks like my driveline. it is leaking, best I can tell at the bottom of where it connects to the axle, at the 6 o'clock area.

I prefer the gray high torque by permatex. A good fat bead should do and then after it cures you can trim it around the rear end.

If it is leaking where the cast carrier housing connects to the axle housing.
It might be a simple tightening of the carrier nuts.
See Lubrication Leaks, (b.)
Manual does not show torque spec on carrier nuts. it just says tighten securely.
Read Number 2 Under Rear Axle Assembly

Isn't that reference about a two speed rearend? I think the leak here is where the torque Tube is pressed into the housing. I wonder if something is cracked.

All tonnage Advance Design Series trucks used a banjo type axle housing.
Requiring a front carrier gasket and rear cover gasket. Page 1 and Page 2
There is one troubleshooting section for all four types of Axles.
See: 4-40 under REAR AXLE AND SUSPENSION there is 3 troubleshooting pages.
Lubrication Leaks, I assume are referring to all four carriers.
Interestingly they don't mention rear cover leaks.
They where probably pressed and definitely riveted and maybe some type of sealant was applied. See Rivets above Arrows 1 and 16
Could be leaking at that joint.
That is a possibility.

It is leaking where the shaft head is bolted (10 bolts) to the rear axle, a very slow drip, at the front of the axle.

Did you try to tighten the 10 carrier nuts?

Yep, it turned out 3-4 of them on the bottom were loose, about 3/4 of 1 full turn on each nut. I haven't seen any more leaking yet, will keep an eye on it. My sincere thanks!