Yes, I know it's not 4x4, but I figured this was closer than off-topic.
Anyway, at parking lot speeds, the rear differential moans/groans. Sounds just like a power steering pump that is low on fluid, or that annoying nasal sound your little brother makes to torment you (ANNNNNNNNNNNNNNHHHHHHHHHHHHHHH). I haven't checked the fluid level yet, but I've read that this is a very, very common issue. Does anyone have any technical insight into what causes the groan? There is no clicking, cracking, knocking, whining, etc, just a groan. I haven't read anything useful yet on the subject. It appears Versatrak fluid is the only replacement for the fluid. So far, replacing the fluid is the only remediation I have seen. If that's the case, then ok, but it would seem like there is something else at work unless the fluid wears prematurely.
Fstop? PartsGuy? Thanks!