I have a f450 with 4.88 and as i come to a stop i get a noticeable down shift clunk. You can here it and feel it. Also when driving in traffic if you accell and decell you can get some clunk noise also.. Is this drive train noise or trans.
The truck is 4x4. Any one else having these noises.

 

i also have an f450 but with the 4.30 gears no noticable noise in the drivetrain. but not sure if your larger gears might attribute to that, but would assume anything mechanical that has any abnormal sounds might lead to premature faliure