VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 39 Chev differential seeping oil

Anyone know if the gaskets used on the differential were the same for chevys of other years? Is this something NAPA should have?

Thanks

The rear cover gasket fit from 1937-54 (cars)....I cut my own from thick gasket material.The original were thin cork.The front gasket (housing to carrier) is made from thin paper.
I have never tried NAPA

Check to make sure it's the diff that's leaking and not oil from the tranny / u-joint housing that's running down the torque tube and finally dripping off the diff.
-Bob

I have cover gaskets if you can not find them.

I changed the torque tube gasket and it's dry but the bottom of the diff seeps. It turns NAPA has them and a bunch of other stuff for 39 Master 85s and Master Deluxes. On their web site you can set your vehicle to a 39 Master 85 and it will list parts for it. It lists gaskets for the diff and from ChevNut's description I was able to order them. NAPA is just around the corner so no shipping for a change. Thanks again.
Mike

The seepage may be coming from the front axle housing to carrier joint.That is the one with just a thin paper gasket - and not easy to replace.Try tightening the front nuts/studs.A drop of that gear oil just hangs there and looks like a serious leak.

Bowtie Bob has a good point. Keep the trans. full and while on level ground remove the diff. fill plug and let the fluid drain until level with the bottom of the threaded plug hole. Unless something is really wrong, i.e. excessive leakage this should work. If the diff. gets too full it may run out the end of the axles and get oil on the brake drums and shoes. My 38 leaves a 3" oil stain from the diff. cover gasket/month. It is not a complete fix but I have slowed/stopped leaks by cleaning the leak area with starting fluid and packing the leak with RTV.

Yup, it's a drop of gear oil just hanging there and a 5" stain below it - nothing serious. Didn't realize it was difficult to yank the carrier out. You see, I have a spare torque tube out of a Master 85 which has higher gears than the deluxe, so I thought I would kill two birds. Were the axles the same on the 85 and the deluxe?
Mike

Everything for the Master 85 and Master DeLuxe is the same except for the ring gear and pinion.....and speedometer gears.Axles are the same.Yes, would be a good time to make the change.You will be amazed how well it floats along at 65 MPH with the 3.73 gears.Hill climbing, especially below 40 MPH will be slower though.You can disconnect the U joint,Slide out the axle shafts, unbolt the housing from the axle housing and slide the unit out.Or if you have the M.85 axle housing install the whole thing as a unit.Would advise checking the prop. shaft bushings either way.Usually loose and will cause annoying vibration thru the body of the car at mid to high speeds.

Good point about the speedo gear, I would have been scratching my head. I yanked the 85 torque tube out of low mile car that was destined for the slaughter house ( a real shame). How do you check prop shaft bushing? Do I just stick the U joint sleeve in it and check for wobble? There isn't much play with the drive shaft inside the torque tube.

The bushing inside the torque tube can have up to .010" clearance.The rear yoke of the U joint rides in the front bushing.That clearance should be the same.For the speedo gears remove the one on the side of the trans. case.The other "half" (drive gear) is pressed on the front U joint yoke.Be sure to get both gears.If in doubt about worn bushings get the Oakie replacement bushing.Its one long bushing that is used to do the job of the two now in the car.The present rear bushing is left in place and the Oakie is driven up to it.Front bushing must be removed.The Oakie contacts different wear areas and will do a good job.
The Oakie is available from the Filling Station and Chevs of the '40's.