The Stovebolt Site Forums The Parking Lot Big Bolts Differential gaskets

Im in the course of rebuilding my rear end in my COE and Im questioning the gaskets on the front and rear of the housing. I would assume the front is thinner so it would have little to no compression once the bolts are tightened, therefore elimiting any issues with the axles and differential gears being a few .001"s off during reassembly. Does that make sense? Or am I being to critical here? Also the front bolts are a larger diameter then the rear, so Im not sure I could even use the same gaskets...

The rear is Felpro #RDS 5049 in case someone with a parts book can help.

Thanks, Jeff

Hy rustednuts, my Fel-Pro book shows RDS 5049 as the diff. gasket for 11000-13000lb. GM axles, the cover gasket for those axles is RDS 4062, hope that helps, if that doesn't sound correct let me know what rear end you're working on.

I had wondered the same question but for my 52 1/2 ton panel. The original gasket was the think paper one on the front side and as expected the thicker gasket on the rear cover. I looked in catalogs and some listed only one....some listed the same for both, and one listed two seperate ones! Well, I ended up using the same gasket on both sides even though now I feel that is not right. I used the felpro gaskets and will watch it close. On the 1/2 ton it may not become an issue but we will see. I did the best I could to see if the "line up" putting in the axles were any different and they felt OK.
Now that I'm finished with it I'm sure someone will say I better change it!!!!!!!!

Hy Achipmunk and guys, the 1/2 ton diff gasket is Fel-Pro RDS 4305, the cover is RDS 4304, hope that helps.

3B, So the 5049 is the front gasket and the 4062 is the rear? If so that helps a lot. I cant seem to bring up anything online for the 4062, maybe it was omitted for the 5049???

Achipmunk, when I rebuilt the rear in my 52 1/2 ton I noticed the same thing. Took me a little bit to figure out and now Im not sure which gasket I used where, no problems yet...

Thanks for the help, Jeff

If I recall, the front gasket was paper and the rear gasket was originally cork, about 1/16" to 1/8". I remember we had all of them nested on a pullout tray under our mechanic's parts window.

SEE, I told you. hehehe....But I ain't pulling that pumkin again unless it leaks!!! The front gasket I used I know is a little thicker but suspect it will be alright. I'm sure it was thin in the beginning from other trucks I have worked on. I figure it was to make it tougher and stonger being almost metal to metal which necessitated the thin gasket for imperfections in the metal. It had to be somewhat tougher because the rearends swivel on the springs. Since I dropped the torque tube and installed a 55 pumpkin I will set the pinion angle, weld it down and give it a shot.....as I said, I ain't pulling the axles and pumpkin again.

A wonderful product called "the right stuff", ends all your leaky cover woes.

As for the actual needs, if the carrier assembly (houses the differential and bearings) is all part of the front cover, the pinion bolts onto it anyway, so the carrier to axle thickness is not an issue. Now gaskets/shims where the pinion attaches, thats another issue all together. All depends on your setup really.

Freq I don't know witch gasket is witch but the thickness of the carrier assembly gasket could cause axle alignment problems.
My guess would be that all else the same shape and holes in the gaskets that they may be a little like a PTO and use different gasket thickness to shim them. I would say if when sliding the axles back in if they move in and out freely without binding the depth that the carrier assembly is set into the axle housing would be correct. So I would try a dry fit first use the gasket you think is right slide it together without sealant torque it down and see how the axles slide in, if you leave the rear cover off till last you can look and see how they align and if you need a thicker or a thinner gasket.