my mechanical background is not very extensive, so i look to all you guru's out there for some help. when i'm on the freeway, and get up to 65 or faster, i hear a low pitch vibration ( almost like a car passing me with a sub box hittin) and feel a slight vibration in the steering wheel.. it's not constant, lasting 3 seconds, disappearing for 2 seconds, lasting 3... etc until i slow down.???? then today i climb under the pass tire assembly and notice the bottom of the C joint is wet, and a drop is hanging down(brownish tint) i'm thinking diff fluid? i assume the two are related but not sure? any ideas? is it possible i blew out a seal of some sort? thanks guys

 

Sounds like yes you have a seal leak. However...the problem you describe sounds alot like an unbalanced tire.
My suggestion for solution? Get your tires re-balanced to solve the vibe your getting, and then see your delear to get the seal replaced.
It's possible that you have a bent axle which is causing both problems

 

Couldn't have said it better myself....X2.

 

x3. Seal needs to be fixed and the fluid topped off. I'd look at tire balance, not uncommon for our big off road tires to become in need of balancing after some miles.

 

remember- vibration in hands on wheel= front tires. Vibration in seat of pants= rear tire. Works every time.Vibration in teeth=driveshaft coming off Best of luck!!!!

 

i'll get em rebalanced... just for future knowledge..... wouldn't a bent axle vibrate the jk all the time... not just at certain speeds.?