SOhappy

Ditto, same here.

belgianmagic

made in mexico or canada...metric

I just changed mine at 14,686 and 'IT WAS GRAY' but 'NOT GROSS'

stickman73

Holy Crap! I just hit 23,000 today and forgot about changing it before now. Hope it does not look bad, but you can bet it will get done more often as i tow 5-10,000 lbs all the time. Guess the front should be changed often too as it spins just as much as the rear.

belgianmagic

I did the 2 rears and the transfer case the first time with snythetic...I haul Hay and heavy horses all the time with 14600 it wasn't too bad...the trans case only held two and a half qts... but special synthetic atf

fordracing19

does the rear just hold 80-90? Have to add any additive like the ford lsd?

belgianmagic

synthetic , and it has the additive in it already

I put the syn in both rears... although the front didn't call for it

4x4not

I guess I should get off my duff and change mine... 22K and I've had the fluid for 6 months. I'll be putting in Redline Synthetic 75W-90

TexasCTD

We don't add any additive to the AAM axles. I think you do on Dana axles like the Fords and 2nd gen Dodges have.


Any GL-5 rated synthetic 75w90 or 75w140 gear oil is what is used.

PoorMansCat

I got a stupid question, my 06 window sheet says "Anti-Spin" rear differential. Are these lockers?I don't hear the clunk of a locker like my 4500 Chevy when turning. Do they have the clutch packs in them? If so, I'm sure there is alot of friction material coming from the new clutch packs.... Exactly which setup is it?...Thanks!

06megacabman

I'm going to put in Royal Purple 75W-90 front and rear but what brand/weight/type synthetic do you put in the transfer case?

Was under the truck last night putting the gas tank vent tube mod on and looked like I should be able to do the X-fer case fluid.

pet05

PoorMansCat-

You bring up an EXCELLENT point. The clutch discs on a "posi" or anti-spin differential has a different setup over an "open" rear. I am wondering if those who claim to have CLEAN fluid after 30K, if they have an OPEN differential??

TexasCTD

You use ATF + 4 and it is already synthetic. I change it out the same time and interval as the diffs and auto transmission fluid. Real easy, just drain it out the bottom hole and fill back up till it comes out the top hole.

TheBigNasty

If the differential is a mechanical locker as the AAM axles should be, they should not require friction modifier, "additive". Only clutch style limited slips require the additive and it is used to reduce the chatter on cornering.

dbunhook

I just did my rear diff. It is an AAM 11.5 limited slip diff. Truck has 6,000 miles.

The old fluid was very dark gray, and very light weight. There was a metal paste on the magnet that I cleaned off.

Replaced with Royal Purple 75w140 as I tow a lot. Royal Purple comes with the friction modifier already in it but it is not needed for my diff.

If you haven't changed your diff. oil you better get busy as the factory stuff is worthless.

rockcrawler304

I waited untill 16k miles and it was also pretty nasty. I wish I had done it at 6-8k instead. As for the front, I checked it and still looks new. I am sure it is because of almost no load on those gears. I will change it the next time I do the rear even if it still looks good.