G80 Gear Oil?

[DanMcG]

I'm looking for some confirmation on the right lube to use in my 85 G80 locking differential.
I'm pretty sure this is the stuff.

Valvoline High Performance 80W-90 Conventional Gear Oil​

Advance Auto Parts - Down for Maintenance

And what's the preferred method for sealing it back up gasket or RTV?

 

[1979 c20]

I seem to remember that it called for a synthetic on the Tahoe I did axle seals on last year. I think I used rtv to button up.

Let's see what everyone else thinks about it.

 

[nvrenuf]

Don’t these need L/S additive too?

 

[DanMcG]

Don’t these need L/S additive too?

I don't know,...but I don't think so. Limited slip is different then a locking diff.
I'm really clueless about these things.

 

[Juggernaut]

The Valvoline 80/90 is what I use in my 14 bolt FF with G80. I have never added any additive. Still works after 34 years I have had it

 

[nvrenuf]

Don’t the Gov Locks still have clutch packs on the sides (in addition to the locking mechanism)?

 

[oldretiredafguy]

I don't know if the Valvoline gear oil has the anti-friction modifier in the formula, but it's very cheap to add that 8oz bottle.

 

[Turbo4whl]

No limited slip additive needed. No friction modifiers either. Newer trucks like @1979 c20 Tahoe calls for synthetic because the seals are for synthetic. Regular 80w90 is what you want.