Rear Axle - Owner's guide says lubed for life

[Doug Kuhlman]

2004 XLT 4x4 with 5.4L
Question: Should I be changing the fluid in the rear diff of my expedition? I've never done it and I've got 230K on the clock. Should I follow the manual that says its good for a lifetime?

Thanks,
Doug

 

[deweysmith]

Unless you submerge it in water or it leaks you don’t need to mess with it IMO.

 

[1997SCEBFEX]

Yes or no is for you to decide.

it's an inexpensive and short amount of time to complete imho. I did mine at year 15. 3 qts and the friction modifier (if you have the LS).

 

[Plati]

If it aint broke, dont fix it? My (excellent) local shop advised change my rear differential fluid at 12 years 160K (2003 XLT 5.4), so we did that. There is a TSB out on that and it advises a change to fluid used. -->http://www.strutmasters.com/v/vspfiles/SMPages/PDFTSB/LincolnNav97-02PDF/TSB05-23-3.pdf

 

[Flexpedition]

Be warned, the friction modifier smells horrible and the scent lingers for hours. Best to do this outside, especially if your garage is attached to your house.