i know GM's owners manual says one gear lube weight, but i was told not to use that for Eaton Posi. i was told to use 85/140. does that sound right? also, which brand is good? i was told 2 different brands by 2 different people. i won't say what they are until i hear back from a few people. i don't want to bias the results

 

what does Eaton reccomend ???

 

I used Slick50 brand 80W-90. I also used a tube of Equatorque posi additive. So far so good here. I wouldn't use the Pennsoil. It says not to use additives with it so it was noisier than usual.

 

The only requirement i belive of gear lube is that it is classed GL-5. And one bottle of GM posi additive used. On the 1/2 tons it has a tag for sytethic gear lube requirement, so why not use synthetic gear lube.

 

i haven;t received the Eaton yet, it is in transit. when i called around for prices, the 2 different places i talked to both said to use 85/140, which is non-synthetic stuff. they said even though GM says to use the synthetic, don't use it. i also heard to stay away from pennsoil too. i heard lucas or valvoline is good. what have others with Eaton used for weight and brand?

 

The eaton comes with a card that tells you what lube to use with the posi. Its Gm#1052271 with limited slip additive#1052358. Ive heard of guys clutches slipping with synthetic cause its too slick.