wrm

Changed The Rear End Cover On My 06 Ctd With 6500 Miles.the Fluid Inside Was A Solid Grey Color Just Like They Paint Navy Ships With.what Do You Think Is Wrong ?

DBLR

Normal color of factory gear oil as reported by all of the people who post after a diff change! BTW, gray was also the color of the grear oil that come out of my 2006 when I drained it at 10K.

IA_James

I don't think quite all the people who have changed the fluid in their AAM axle have reported it, but it's certainly quite a few. I kind of wonder if that isn't part of the reason for the 15k miles service interval. On mine, when I took the magnetic drain plug out for the first change it looked like a mushrooom with all the steel on the thing.

own1bigtruck

I changed mine out at 4500, and it looked the same way in the rear, it was almost black in the front axle!

Hounddog

The reason for the 15k interval was thats a severe duty interval for heavy duty work trucks.

wrm

Thanks puts my mind at ease.

boostjunkie1

Did mine last week at 12,000 miles and the rear was grey and the front was almost clear. Very little metal on the magnet and the gears look great!!

IA_James

At least on the older (03 and 04s anyway) it doesn't specify that. It just says every 15k. Unless the mere fact of toting the truck around qualifies as heavy duty for this particular axle, which would be in line with what I've come to expect from DC.

Hounddog

Actually several moons ago I talked to a higher up with AAM.He said it was AAM that came up with that interval and a re useable gasket so the pumpkin could be wiped out with fliud replacement.Said these if these trucks were worked hard they wanted that drain interval for longivity of the diffs.

Spooler

Gray color is normal. They put a protective coating on the ring and pinion to help seat the gears and prevent rust when no fluid is installed. Look at the diff assembly where no gears have meshed. Easy to see.

redeyedracer

looks like some kinda graphite additive....???