D2 diff refill.

[Pat in RI]

My D2 LS diff on my 03 ST was making lots of noise. According to Ford it is sealed for the life of the truck. It has been working but really noisy since I bought the truck. I bought a new heavy duty rear 10 bolt cover with gasket from Amazon. I removed the old cover which drained the 75/140 fluid into a catch pan. I completely cleaned the inside of the diff and checked for metal filings etc, found nothing. I tapped the bottom of the diff and top ( clearing the carrier assembly and retainer) using a 1/4" NPT tap and installed 2 tapered plugs. I refilled the diff with 3 quarts of Valvoline 75/140 with friction additive and tightened the top fill plug. The diff is much quieter and no leaks anywhere.

 

[dvdswan]

Nice work. Are the 1/4" holes large enough to drain and fill? Curious if 3/8" or larger would be better.

 

[Pat in RI]

Nice work. Are the 1/4" holes large enough to drain and fill? Curious if 3/8" or larger would be better.

Yes. l used the Valvoline flex fill bags to fill it or I could have used a standard small diameter flexible funnel in my garage. I had no problem filling it. Larger would be better, no doubt, but this was easier to do. When I replace the carrier, this will be adequate for maintenance.