Rear diff service

[CKeeler]

So, today I serviced the rear diff on my GT for the first time. 50k I might have waited too long, but no noise and the oil was still pretty clear. What I did notice was when I drained the fluid, it seemed that there wasn’t much fluid in the diff. And since it’s never been serviced, this would be what came in it from factory. Owners manual specs 1.37 quarts for the rear diff. There had to be just under a quart of fluid that came out. I haven’t measured what came out yet, but it definitely doesn’t seem to be 1.4 quarts.

No signs of leakage or “sweating” anywhere. My question for those who have serviced the rear by themselves...
Is this something you have noticed also? Or does the amount that comes out from factory close to owners manual spec?

 

[oddball]

You're never going to get all the oil out of a diff. Don't worry about it. The diff housing is *tiny*.

Don't just plop in 1.4 qts. Fill per the manual. I'm 99% certain it's the normal fill-until-oil-comes-back-out method. That's common across almost every differential made in the past 50+ years.

 

[CKeeler]

You're never going to get all the oil out of a diff. Don't worry about it. The diff housing is *tiny*.

Don't just plop in 1.4 qts. Fill per the manual. I'm 99% certain it's the normal fill-until-oil-comes-back-out method. That's common across almost every differential made in the past 50+ years.

That’s pretty much what I ended up doing. It took just about 1.5 quarts.

I ended up measuring what came out and it came out to just at 1 quart. Crazy

And even the manual doesn’t show you how to fill it either. The manual on my 06 mustang had the fill procedure in it