Engine/Transmission (1998.5 - 2002) OE Axle Lube in Fr/Rr Diffs

[spacecadet]

Getting ready to replace both OE diff fluids in preparation for heavy towing, and wanted to be sure what is in there now. The DC service manual for 2001 says on pg 0-5 that the front axle lube is 75W-140 synthetic and the rear is 80W-90. I believe the rear is what they say, and will replace with 80W-140 syn, but the front couldn't really come from the factory with 75W-140 syn could it? Don't know any easy way to tell when I drain it. If it is really syn I'll stay with that, otherwise go with dino 80W-90 since I rarely use 4WD. Thanks for any thoughts.

 

[NIsaacs]

My '01 Owners Manual says the factory fill (front) was MP GL-5 80/90 and the rear was MP GL-5 90 wt. I use 80/90 front and 85/140 rear dino. With limited-slip, friction modifier is required, however I don't use it as I like a more positive engagement.



Nick

 

[KKlingbeil]

I run 75/90 Synthetic up front and 75/140 synthetic in the rear. Has worked well for me thus far. I would recommend synthetic for sure. Yeah its a little more expensive, but it isn't something you change every 5,000 miles.