[wafrederick]

Also stay away from synthetic gear lube,a big cause of rear end failures.I know of this happening to 3 rear ends.My father's friend Rich knows about it,replaced ring and pinions due to synthetic gear lube.Rich also has a 1983 Monte Carlo with a 9" Ford w/a Detroit Locker and was told not to use Synthetic gear lube.Synthetic Gear lube will screw up Detroit Lockers.