got a 1999 1500, with lotsa kms on it, diffs are good, except for a pinion seal leak which I'm gonna do at the same time...but was wondering what other guys recommend for diffs with lotsa kms...stock diffs, no lockers or anything. Rear whines a little off acceleration but not bad at all. I have heard some guys use Lucas or a mixture of Lucas and ? Thanx

 

IF you have the Limited Slip Rear and it still works you need the proper additive to go along with the rear diff oil..

 

Fill the rear with 80w90 (any brand) and half a bottle (4oz) of Lucas limited slip additive if you have a LSD. Fill the front with 75w140 I think? And no additive.

 

get the less expensive walmart brand gear lube in the gallon jug for about $12. either weight is fine.

as said, if you have an LSD, add the friction modifier.

 

I would do lucas gear oil along with the additive for limit slip if you can afford to, probably at least two bottles.

any local auto parts store can tell you which weight you should put in for factory specs but you prob want to go something thicker