8.5 rear fluid and gasket questions

[mebe007]

ok so i got a package today from summit. i now have my girdle cover for the 8.5 woohoo. so my question whats the best fluid to run in the factory posi's and how much? any additiive? now when i put the cover on do i use the gasket or rtv?

now when the cover comes off im going to change the axles. i know i pull the cross pin to remove the c clips. im going to change out the axle bearings and seals since i have them. anything special on those?

 

[khan0165]

I just did this the other day on my 8.5...
I used 80w90 synthetic. I believe that's what most recommend, but you can also go a little thicker like 90w110. I would not recommend anything thinner than 75w85 though.

I used a Valvoline LSD additive... whichever you use, make sure it is good for clutch type LSD systems (some might only be good for Gov-lock systems). It should say on the back. It came in a little 4 oz. tube and I picked mine up from Napa. Some brands like Lucas have this additive already in the gear oil. You need to use 4 to 6 oz. of this additive.

I used a gasket, with RTV Black. The trick is to apply a little all around, and spread it around like a thin film. I applied it on both the housing and cover, waited 15mins to get tacky, applied the gasket onto the housing, and then put on the cover.

 

[chevy2480]

Two quarts of Hypoid Gear oil. I recommend a good quality synthetic, such as Red Line. If you choose to use normal Hypoid Gear oil, be sure to get some "Equa-Torque" or similar positraction additive. The synthetic gear oil usually does not require this additive, but if you get chatter or noise when cornering, try a bottle of the additive. Also, take a look to see what the synthetic manufacturer recommends. If you use regualar gear oil i have used in the past i believe it was 85-90
With the girdle 3qts
Use the gasket with a thin coat of rtv
Also on the girdle do not put more then 3lbs torque on the two girdle bolt or you will break them.
You will need a puller to remove the axle bearings from housing

 

[mebe007]

oh ok. i have a puller. is there anything special about putting them in? or should i let them be for now and just throw in my axles and roll?

 

[79loserbluebu]

You don't have to use the gasket, sealing it with RTV will be fine. If it's anything like the one I have they send you a pretty nice thick gasket just smear a little on both sides and you will be good.

If your budget allows you should throw a set of Moser replacement axles in there. There's quite a few TR's running the stock differential with a set of Moser 28 splines in the 9's with no problems. I'm glad I did the axles when I did.

 

[mebe007]

as a matter of fact i am putting moser 28 spline axles in it. they are sitting next to the diff in my shop floor brand new in the box.