cliffyk

It (rear-end lube) depends upon what year's owners manual you look at, but in general the recommendation has been for either 80W-90 for dino oil, or 75W-140 for synthetic.

Only 80W-90 is listed for 1996 through 2000, both for 2001 through 2004, and only the 75W-140 synthetic for 2005+.

In 2003 the use of friction modifier was only recommended with the dino juice--that was the only MY specified--it probably made the LSD a bit noisy or too aggressive for average customer's tastes and they back-tracked as a NVH issue...

Metalmania82

I've got a 2001. Sounds like people are using both weights for the diff fluid. Like I said, I didn't get a manuak with my car or else I'd just go with whatever it said in there.

cliffyk

You can download a manual here--you will find that it lists 80W-90 if you use mineral oil, and 75W-140 if you use synthetic--both spec'd as Motorcraft brand of course, and both requiring that 4oz of friction modifier be added as well...

Metalmania82

Thanks for the link.

I work at Acura, detailing cars mostly. I jumped on the computer to see if it had an info for the diff. It said 80w90 for 7.5 gear and 75w140 for 8.8 gears...

Metalmania82

Ok, so 85w90 it seems. Anyone tell me how to figure out which gears I have?