Just wondering what rearend gear oil to use with my 02 Silvy? I have the 3:73 with G80 locking diff, but im hearing a lot people are using Amsoil or Royal Purple and from what im founding out the RP is getting a bad rap due to some inhouse testing, but its not real world or everyday testing. Amsoil is kinda hard to come by where i live, but RP, Mobil 1 syn, Castrol and GM's brand is a plenty, but what does everyone use or recommend for their diff fluid?

Sorry if this has been posted before or a ongoing topic

 

Mobil 1 syntectic is what we use at the shop or else royal purple. The cars with out posi or anything just some kendal gear oil.

 

As long as it's synthetic, you'll be fine with whichever brand you go with. I usually get Mobil1 75w-90

 

Mobil 1 here also...

 

What do you guys suggest for us clutch-type posi guys?

 

mobile 1!! ftw

 

i like amsoil gear oil .

 

For those running Mobil 1 syn, do you use the GM additive for the posi-trac? I know i had to use 2 bottles of the stuff when i had my 96 C1500 with locking 3:73. But not sure on the 99 and newer trucks?

 

No sir, the G-80 doesn't have clutches and does not require the GM whale sperm, just about 2.1 qts. of syn 75w-90

 

Thanks for the info!