Front End Vibration

[Coastal Travelers]

We have a 2003 24 RB & recently replaced the steering cylinder because of vibration occurring at 55 mph. This alleviated the issue for a while but it has returned. If you pump the brake, it will eventually stop. Anyone had this issue? If so what was the diagnosis? Could it be a brake caliper sticking.

[whemme]

Is is a minor or a major vibration? If it is a vibration that you can just sense in the steering wheel, you might have a front end alignment problem that is starting to cup your front tires. Look at the inside edges of your front tires and see if you can detect any cupping of the tires there. If so, get to a truck alignment shop and have your front end aligned properly.

The twin I-beam front suspension used on the Ford E350 and E450 chassis is prone to causing this tire cupping if not keep in good alignment. Once this cupping starts it is hard to stop and after re-alignment, also them rotate the front tires by removing both tires from their rims and reversing the rotation so that the side of the tires with the visible cupping now run on the outside my stop further cupping. If the tires are cupped badly enough, replacing them with new may be necessary.

Usually by the time the cupping is bad enough that you can detect the resulting vibration in the steering wheel, the tire cupping will be easily visible.

[Coastal Travelers]

There is no alignment issue. It is a major vibration causing the steering wheel to shake.

[dsfriday]

Thought I responded to this post, evidently it didn't stick the first time so I'll try again. As Bill mentioned above, tire cupping could be culprit but you should be able to spot that on the tire and that would, I think, tend to be noticeable way before 55 MPH. I would first check wheel bearings by jacking one side then the other off the ground. Don't need much, just so coach weight is off the wheel. Grab the tire with both hands, one at 9 o'clock the other at 3. Try to wiggle the wheel in and out. Shouldn't be any noticeable play. If there is have someone watch the tie-rod connection while you wiggle wheel, play could be coming from worn tie-rod which would tend to promote loose sterring not a vibration, if the play isn't at the tie-rod, then wheel bearings need further investigation, at minum repacking or replacement. Second, once you have determined wheel bearings and tir-rods not he problem, have front tires checked for balance, not the static kind but actual spin balance above 70 - 75 MPH. An out of balance tire really becomes noticeable at the 55-60 MPH mark. If the balance is okay then possible you a rotor that is out of balanced but that would be very rare. As for a sticking disc brake, I think you would notice the tendency for your coach to pull to one side or the other. A warped rotor tends to produce a shake versus a vibration in the steering wheel, if severe at any speed or just when you apply the brake. You mentioned you had the steering cylinder replaced, were you referring to the steering sector, boy that had to be expensive. Usually a worn sector promotes loose steering, that is you turn the wheel sligthly before any change in direction, versus steering vibration. In any event, need to get fixed before you venture far. Good Luck.

[karls]

Our 1998 24RB had a shake/vibration that behaved like an out-of-balance tire. But after six months and a couple more balancings, I took it back to the tire outfit that sold it and they replaced it for free. Problem solved!

There was some imperfection in the tire - maybe the cords weren't uniform? When jacked up and rotated by hand the tire looked perfectly round, but there was something wrong with it.

Try switching both of the front tires to the rear and see if that fixes it.

[whemme]

dsfriday,

I think what Bob was referring to as the steering cylinder was actually the steering damper which is like a shock absorber connected to the steering linkage and can be seen when looking under the front bumper of a E350 or E450 chassis.