Gear oil/diff and tran maintenance

[BMD]

Looking to do a fair amount of fluid swaps as I have no idea how long since(if ever) they were done. I have an 04 xlt with 373 limited slip. Are both front and rear limited slip? Manual says front is 80-90w and rear is 75-90w, can you just use 75-90 in both. Any oils better than the other, mobil1 says for limit ed slip, would you still need to put in the friction modifier?

 

[silverfox103]

I have a 2005 Aviator, and what is recommenced and what I have read is 80-90 in the front and 75-140 synthetic in the rear.

Tom

 

[lincolnshibuya]

75w140 sythetic for the rear (updated)
the friction modifier on the Mobil1 LS is not enough, just buy the bottle in the dealership ($5-$8) and drop all of it at the rear only.

 

[BMD]

Good to know about the weight change. What is the additive for the differential, i thought it was xl7 but i can't find online and really don't feel like going to the dealer, not close and haven't liked past dealings with them. What fluids are compatible with Mercon v?

 

[lincolnshibuya]

https://www.amazon.com/Ford-XL-3-Fr...&sr=1-1&keywords=motorcraft+friction+modifier

almost same price (with tax) in dealership (in my area) if they charge you double ran away!