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Which viscosity of gear oil?

David67

Active Member
I have a leak coming the gasket between the housing and the pumpkin. I don't remember which viscosity that I used only that it royal purple. It's an 8 inch with a trac lok.

Thanks
 
NOTE : I guess , 75w85 with special additiv for your trac lock. If its a true trac trac lock you don't have to add that additiv.
 
I broke mine in with 80w90 but have moved on to 85w140 Royal Purple since. My source for my rearend stuff (Quick Performance) suggested this route and Currie also recommends 85w140 as well. To be honest, as long as you have good lube in there regardless of weight I'm sure you're fine. Make sure to mix in an additive though with the stock Trac-Loc.
 
i don't remember the weight. But for the additive:
Yukon Gear & Axle Limited Slip Friction Modifier.

That is what came with my trutrac
 
Truetrac diffs do not require a friction modifier. That's for clutch pack style differentials.
 
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