Tire Rumble Or Bounce?

[fzeuner]

I have a 2012 Expedition on a Freightliner Chassis. I'm on a trip from Florida to California and back.

When I get up to 55 or 60 I start to hear a sound from the front tires that sounds like a out of balance situation. Instead of a steady tire singing on the pavement it starts to get intermittent. The sound is like weee,weee,weee for lack of a better example, instead of a steady weeeeeeeee.

I had two new Michelins installed on the front in South Dakota thinking is was a tire. the problem is still there, but less noticeable. I've also noticed that it is more pronounced on bumpy or choppy roads. Its sort of like the shocks are bad and not damping the axle movement or bounce. I have 20K miles and it is still running on the factory shocks. The unit steers fine and handles fine. it had a 4 wheel alignment at 10k. This didn't just suddenly start it has been coming on slowly. I've looked at Bilstein shocks and am on the verge of finding a shop that can replace the originals with the Bilstein's.

Any comments and or advice would be appreciated.

Frank

[dickandlois]

Frank,

Have the tires shown any unusual wear? Front end Alignment?

Front wheel bearing adjustment or leaking of the wet bearing oil?

Have you had the Ride height checked and tested the air ride system for any air leaks?

Front suspension bushings or stabilizer bushing unusual ware or loose mounts?

Can not remember all the different chassis, but does your coach have a Tag Axle?

Any noticeable difference when driving in a cross wind?

Have you checked the 4 corner weights on the coach to see how your load is distributed?

This would most likely change during your trip, just trying to tie things together.


Rich.

[wolfe10]

Rich gave a pretty complete list.

But, I would start by checking the front tires for RUN-OUT. Takes less than 5 minutes. Even a perfectly balanced, egg-shaped tire will do what you describe. If run-out more than about .035", get it corrected (loosen, rotate wheel and retorque lug nuts/rotate tire on rim/true the tire). Then balance the tire-- preferably balance the front tires on the coach.