In recent C4500 posts, I told of the oil leak following injector replacement that coated my truck in oil.

After the repair and half-ass underside degrease, I noticed a funky smell that I attributed to their degreaser burning off the exhaust.

However, a week and 1,000 miles later, the smell is stronger, and is rearward on the truck. It goes away in a few minutes, but you can smell it around the truck (downwind of course) for the first minute or two after stopping.

It smells to me like gear oil. The rear diff is not hot, just warm. The level is good, its Royal Purple synthetic with about 90,000 miles on it. Looked clean but clear in color the last oil / fluid change - I am wondering if its breaking down rapidly, or if I have gear issues out back.

No gear whine, no chatter around corners, just the funky gear lube smell as described. No visible leaks at pumpkin or axle ends, either, unless just a little is starting to get past the seals and is burning off the brake pads...now there is another theory...whaddya think?

Ever had a C4500 WITH A STINK?