I had my right wheel bearing assembly replaced last month on my truck and ever since it has been making a noise that sounds like the spinning line on a weedeater and/or if you put a baseball card on your rear bike tire. He says there is nothing mechanicly wrong with it but I think that is B.S. Any idea what it could be??

 

The bearing should make no noise at all....someone is shooting a line of bull and is probably too lazy to diagnose the trouble.

I suggest the bearing/hub be disassembled and investigated for proper alignment of the rollers and races and proper amount and quality of lube.

Some of the replacement bearings are made in China; my experience with them has not been a positive one. One set of bearings had the angle of
the conical rollers so far off that the roller large-end edge was the only thing contacting the race.

The preload on the bearing may be misadjusted as well....it'll show when the system is disassembled.

BTW/FYI: The only lube I ever use for wheel bearings, front end parts and U-joints is Valvoline moly-lithium NLG1....it's the best dam*ed all-purpose grease around.