I have a 1992 F-150. It has 217K on it. The rearend fluid has never been changed. I want to change the fluid what type should I use? Is it worth the trouble on a truck with this many miles.
Any advice is appericiated

 

For safety sake i would get the truck on level ground and jack it up. Take the cover off and turn the rearend to see if any of the teeth are chipped on the end. If everything looks fine put regular 80-90 in it, if you have any chipped teeth put 140 in it.

 

yeah. sounds about right.