I'm going to change the gear oil in the front/rear differentials and the transfer case this weekend. My only question is this: does it have to be "hypoid" gear lube in the differentials? What exactly are the differences between hypoid and multipurpose?

 

Hypoid are the curved-face gears on the ring and pinion requiring a hypoid gear oil with the right EP (extreme pressure) additives.

 

I did not know that

 

Well the multipurpose bottle does say "extreme pressure", but I think I'll go with a hypoid gear oil.

 

The stuff I don't know would fill volumes...

 

From what I've read elsewhere on this forum:

D60 front - 3.25 qts
D70 rear - 3.5 qts