Rear Diff Fill

[wrecker03]

I'm replacing the differential cover and gasket because it's leaking. When I replace it where do I refill it with lube? Is it on top of the differential?

 

[retorq]

Passengers side upper half, there is a plug that a 3/8 extension will fit in, pull that and fill from there.

 

[bai78]

Do yourself a favor & make sure the fill plug comes out before removing the cover. Otherwise you're stuck like chuck & cannot refill it. One way to do it would be to fill it through one of the top bolt holes. Yeah, slow as xmas, but doable.

 

[wrecker03]

Got it thanks......just wasn't sure.

The cover had silicone rather than a gasket. There was silicone everywhere even in the bolt holes so I ran a tap in each of the holes to clean them out and cleaned everything with brake cleaner. It was the lube breaking down the black silicone and was causing the leak. I was a little concerned because the lube leaking out was so black I thought it was cooked. Once I got the cover open the lube coming out was actually really clean.

 

[blueflamed03]

good info, quick question, whats' the rear oil capacity, anyone know?

 

[bowtiefreak]

Capacity is fill until is it leaks back out then it is full. Seriously

 

[bai78]

American Axle 8 1/2 and 8 5/8 Inch Ring Gear 2.0 liters (2.1 quarts)
American Axle 9 1/2 Inch Ring Gear 2.6 liters (2.7 quarts)
American Axle 10 1/2 Inch Ring Gear 3.08 liters (3.25 quarts)
Dana 11 Inch Ring Gear 4.0 liters (4.2 quarts)

Axle Lubricant (GM P/N 1052271 or SAE 80W-90 GL-5 Gear Lubricant).
Limited-Slip Differential Friction Modifier (GM P/N 1052358 or equivalent).

I have a Mag-Hytec on mine & it is 4 quarts. I just use RP since that is what has been used in it since the gear/trutrac swap.

 

[Popeye]

I had the same issue of leaking due to rust. The bolts pretty much fell apart and had to drill out 2. Anyway the question is how would i recongnize the/a limited slip (Yes did the turning the wheel thing) but i found that it works as a 'non' but looks like one (but could be worn out). Did not see any shavings on the magnet either. Not too conversant with these types of LS diffs so looking for some tell tale signs to recognize one.

 

[blueflamed03]

thanks B !!

 

[MDJR]

Stupid question, and I know this thread is really old, but how do you know what size the rear diff is? I just changed the fluid on mine and I put almost 3qts in my 2002 tahoe LT 4x4. Do I have the 9.5 inch or the 8.5?