Rear Diff Fluid? Vibration?

[ryan.sampson]

So this is actually about my father's 05 dodge 1500 hemi 4wd:

he's at around 75k so he decided to have the tranny and rear diff flushed and new oil at the stealership... since he got it back a month or two ago its progressively developing a vibrations, it seems way worse under load or under hard braking, seems more like a driveline problem, not so much a tire misbalance. anyways i got under it to check the ujoints and check for anything else obvious, and found that the pinion seal was leaking pretty good. i've never changed the diff fluid but can you put too much in and blow the seal? or is this some kind of coincidence? i know the super duty's have the breather but i didnt see one on his axle... any thoughts??

[Evil Eye]

Kiss that rear end good bye especially if it starts making noises. 4 of my buddies have had their rear ends go out on their Dodge 1/2 ton pickups. Thankfully, my wife's has held up, but I am concerned it's on borrowed time.

The other thing to consider is that when I had her truck regeared (she has an 02), the shop wanted to put in a synthetic fluid, but I read the warnings on Dodge's site and had them put in the stuff that was specified. I'm not sure if it matters, but just something that came to me as I was writing my reply.

[sinner6.0L]

grab your pinion flange and see if it moves around at all. a loose pinion flange nut will cause this and the fluid loss, same if the pinion bearings are starting to go.