2000 f-150 4 wd. with 112,000 and running strong! I never changed the tranny oil (manuel) or the rear end oil. Advice please!

change them both. tranny takes mercon (the same fluid as an auto) the rear end will have a tag on it that will say 75w140 or 80w90 the tag will be attatched to the cover bolts, and its metal, so should be there still. they seal with silicone, no gasket. if you have limited slip, you need a bottle of friction modifier...add it to the 1st quart of fluid. if the metal tag says synthetic only, its 75w140. friction modifier might only be available from ford, dont know about aftermarket availability, but it is expensive. if you jack up both rear tires, and you cant spin both tires by moving one wheel, you have limited slip.

Thanks for the info!

Glad to help...just remember, a ford tech just cut a potential job be telling you.:)

You can get the posi additive at any parts store and put this in before the gear lube.The posi additive can be smelly and stink.