Every once in awhile, mostly when the truck is cold, I get a weird clank sound when I shift to R or D and start rolling....
(I shift into R or D start going, and then a sec. after I start rolling I get a clank)
What could this be? is it normal? I think it may be the rear diff.
I did just change the fluid to RedLine LSD. But it did this before I did the change.