Posted by POW on October 15, 1999 at 09:24:31:
In Reply to: Gear Oil posted by Mike M on October 12, 1999 at 18:24:41:
In all of the above uses, I'd opt for plain-old 90-wt (or 140wt if you are in a hot climate) gear oil. Buy it in a 5-gallon pail with a top pump, so you won't have to go scrounging for it later. A lot of press has come & gone about the merits of various synthetic oils, but the fact still remains: The 200-series and earlier transfers are supposed to run hot, well over 200F. Many synthetic or Moly-enhanced oils have much improved "creep & crawl" charicteristics, so you will find a lot of it on the tailgate and ground. I do not believe there is any significant reduction in wear of the differential assemblies or transfers from these oils in this application. The older oil won't flow over the slingers and past the seals as much, and provides all the lube the units will ever need. I have had the same gears and transfer in my M37 for almost 250K miles, and they still work OK using straight 140wt. DG