nancygrl

Hey all,

We're changing the gear oil in the TA this weekend. While we're at it we are also going to replace the ratty, rusty stock cover. I picked up a dorman replacement at the part store. Was expecting raw steel. It looks like its painted or coated black inside and out. Will be ok to permatex as usual?

Youngblood16

I would think about ruffing up the area where the permatex is applied just to make sure it has good grip. Ive know chrome/other smooth surface parts not seal correctly due to their smooth surfaces. Try not to rough up any spots that will be exposed to the external air so as to not rust the new cover. If this happens you could also wait a day and then either add permatex onto the bare spots or give it a couple coats of rattle car around the perimeter of the cover. Have fun!

nancygrl

Thanks for the help....Another question with the gasket....Why are there no cut outs in the gasket, gm or felpro at the 3 and 9 o'clock position for the axle lub holes?

FirstYrLS1Z

iTrader: (4)

Those are not 'axle lube' holes,they are holes for inserting a 'case spreader'. A case spreader is a tool/fixture for forcibly flexing the case open to allow easy insertion of the carrier with its' accompanying shims. The axle bearing get plenty of lube in normal operation.

https://www.google.com/search?q=case...ed=0CAcQ_AUoAg

01ssreda4

iTrader: (96)

^^^^true story.

nancygrl

I did a search and saw where on a 8.5 that's what they were called and the gm gasket has a slot cut out where those holes are located, thought it was the same for the 7.5......Rear end diffs is like voodoo to me

Thank you for the info, much appreciated

guppymech

iTrader: (7)

While those holes are for a case spreader, the stock diff cover for a 12 bolt has ramps that lead flung oil to them.

FirstYrLS1Z

iTrader: (4)

The OEM gasket does not have those holes that you were questioning about in post #3 either. The little 7.5" housing has no 'beefiness' anywhere and those housing holes had to go thru to the axle areas so that the factory spreader has enough grip/bite to not slip out. I built my own spreader but it was easier to fabricate using the cover bolt holes.