i won't use synthetic gear oil in the rear. posi clutch went right after i used it in the old rear end. I'm sure its ok for newer but old and near its end, not so much.

 

I don't think its synthetic it doesn't say it is

 

yes use the additive

 

thank you

 

ok i checked out my rear last weekend and heres what i found. the pin that hold the axles in was stuck in there and all pitted on one end. the oil looked good besides being a little burnt. i changed the pin, two c clips, and oil and the bracket no longer hits the rotor. it doesnt make sense to me because the part of the pin that was pitted was no where near where the axle would come in contact with the pin put it fixed the problem...lol