My 2001 dodge 1500 5.2 has knock when in 4x4 high and low. It sounds like it is coming from the transfer case. And it just started knock/rattling when you take your foot of the petal at any speed. I don't know if these two problems are connected or not. The u joints are new. There are 180xxx miles on the truck and it is a automatic. Any ideas? Thanks.

 

Drop the rear driveshaft, pull the tailhousing off the t-case, and check and see if the snap-ring is still there.

Checking fluid level wouldn't hurt either.