Well, I did my own diff fluid change outs on both. Was impressed for this being the first time I did this. Can't for the life of me wonder why I always let them suck it up and pour it in. I did just that @ 5k. They filled both diffs with Royal Purple. I have 18.6K right now when I decided to change it again. To my surprise, the fluid looked and smelled as if it were poured an hour ago. I didn't see any metal flakings and the gears looked like nothing touched them. This time I filled up with Mobile 1 75 - 90. From now on, I'm doing my own. Thanks to y'all for building my confidence on this rather simple task.

 

you should have stayed with the royal purple. It is superior to mobil in my opinion. That is what I run and what I have had the best luck with.

Brad

 

Mobil1 is really good stuff.. But I second the vote for Royal Purple 75w90... Gears look unused at 50k and I tow pretty heavy regularly..

 

At the next gear lube change you might want to think about replacing the rear cover with a PML diff cover. Added capacity (5qts) and has a drain plug with a magnet. Pics are in my photo gallery.
I'm using Royal Purple 75w-140 for added protection in our hot Texas climate.

MikeyB

 

If you have a limited slip differential you'll need to add the slip modifier.

 

Nope, not with the AAM axles in the 3rd gens. That was true with the Dana's though.

 

HI Mikey! Yeah, in part that is why I did it myself. I was going to put one on, but my planning wasn't worthe a hoot. Did u get a good price on yours? and where?
Thanks....

Geico, as dan da man posted, you do not need to add the modifier as mobile, rp and the others protect the slip. It is also stated on their products. It also states on their products you may add, but it is not necessary.

I know, RP is a great product, I have been a fan of MOBIL products so I decided to put it in. But, when I changed the RP out with 13K on the ticker and saw how clean it was and the smell was like out of the bottle, I was thinking I should of gotten it again. Well, at least I'll see how MOBIL is on the next change.

 

nonford,
I order the cover directly from PML. http://www.yourcovers.com/dc_10361.shtml

MikeyB

 

Can you give any sort of factual basis to your recommendation or is it purely subjective? I prefer to stick with the Mobil1 and can't see a reason to switch to RP.

I got my PML covers from DPPI. So far I've only installed the diff cover but it looks/fits great. Same price as ordering direct plus the good service from Mark Craig that we've come to know.