Leaking Differential Bolt-1950

[beerczar1976]

Noticed my rear diff. dripping a bit lately.  Finally had a chance to crawl under there with a wire brush to clean off the crud.  Turns out the bolt at 9 o'clock is weeping.  Tried loosening bolt and re-torquing to 15 lbs. but no luck.  Obviously the manual prescribed white lead is no longer available.  Any suggestions?  Guy at O'Reilly suggested Magic black silicone sealant.  Haven't tried it yet.

[Beemon]

Which side, is it the diff cover or the torque tube flange? I have had great success with the black silicone sealant on the differential. Not one leak since I did mine.

[beerczar1976]

It's leaking from the cover side. Though I bet there's some weeping from the flange side as well since the whole diff. pumpkin is covered in the typical layer of road crud/oil grime on an un-resto'd car. I have a new cover gasket, but have so far wimped out on doing the full job. Did you put the sealer just on the bolt threads?

Edited August 1, 2017 by beerczar1976 (see edit history)

[Beemon]

I have a 56, so it's cover less,  but I basically double coated the flange gasket and torqued to spec, sealing the gasket and bolts. I've been using synthetic oil since and haven't had any leaks. 

[1953mack]

18 hours ago, beerczar1976 said:

Noticed my rear diff. dripping a bit lately.....Turns out the bolt at 9 o'clock is weeping.....Obviously the manual prescribed white lead is no longer available.  Any suggestions?  

Weeping from above the gear oil level line leads me to believe that thermal expansion of the gear oil without a breather vent relief is the culprit. Have you checked your axle seals and gaskets too?  

 

Al Malachowski

BCA #8965

"500 Miles West of Flint"