Gaskets for differential

[lfg1931]

When I unbolted the torque tube from the differential housing on my 1931 AA truck I found there were no gaskets at that location. There was a steel shim in the shape of a gasket (.006" thick) between the differential flange and the pinion flange. I am assuming this was used to give the proper clearance between the ring gear and the pinion gear. This truck appears to never have been apart. Even though there were no paper gaskets it appeared to never have leaked oil. Was this the way they were assembled at the factory (without gaskets)?

My second question pertains to the gasket set I purchased for the differential housing (1st picture). It includes a long strip of cork but I don't see where that is used.

Any help will be appreciated.

Larry

[Bob C]

There is a slot in the differential flange or pinion flange, can't remember which, that the cork
gasket goes in. You may have to dig around to find it as it will be smashed flat with the metal.

[lfg1931]

Thanks Bob, I will check it out.

Larry

[Drew Mashburn]

Larry:

I only had the steel shim too. No gasket. Maybe the shim is soft enough so that a gasket is not required.

-- Drew

[mbailout2]

Since I have my differential apart, I can show you where the thin cork gasket is fitted into the groove on the back of the flange of the pinion gear sleeve.
There are no other gaskets that I am aware of other than the differential housing gasket.
The metal "shim" #AA-4659, is a shim (.005"), and not a gasket.

Mark

004 (3).JPG (36.18 KiB) Viewed 4380 times

[lfg1931]

Thanks for taking the time to send the picture, it helps.

Larry

[tiredtruckrestorer]

Maybe I should mention that before April 1931, on the '30-'31 bevel gear rears, there will also be a .060 shim used between the pinion bearing housing and the axle housing. The .005 shims may still be required with this .060 shim to get the correct backlash. According to the Service Bulletins the axle housing neck was lengthened 1/16" and the .060 shim is not needed after this date, but the .005 ones are added as required to get the correct pinion adjustment. (.003-.008 measured at the splines). No other gaskets or sealer are used with these shims. Just though I'd add this note for the guys swapping gears sets and housings around.

Keith

[mbailout2]

Good info tired guy. I saw the .060 and .070 pinion bearing sleeve shims in the 30-31 AA Ford's Part List, but in the Service Bulletins, February 1930, it only states that those shims are available, but couldn't find info as to why and when they were used. I must have missed something? Maybe Neil could chime in here with some additional information.

Mark

[Chris Haynes]

I bought my rear end gasket set from Snyder's. It came with different thickness shim gaskets.