I have a v10 engine, so I'm probably in the wrong section but here it goes anyway. The truck is new to me. 2004 4x4 crew cab automatic. Just bought it from its original owner with 31,000 miles. Going through it today I noticed that on the driver's side wheel u-joint that there is a rubber washer/seal that is loose. Looks like it should be in the axle housing, but its not. Its free for me to spin around by hand. Is this something to worry about?

 

It is just a dust seal. Most of them are flopping around just like yours. Not to worry about.

 

Had the same thing happen to me. Took it to the dealer and had it fixed, found out later after reading on here that is was not a big deal. looked like a big rubber washer or o ring.

Screwed at the stealership again!

 

There are seals in the axle at the differential that actually seal the fluid in.

 

Nothing to worry about.