Severe Shimmy in Steering Wheel

[john_harris]

I just returned from a wonderful 5,000-mile trip out west in a 2007 Holiday Rambler Endeavor, with just under 30,000 miles on Roadmaster chassis. I had observed minor edge feathering on the front tires indicating an alignment issue but nothing major.

About 500 miles from getting home, noticed some minor shimmy in steering wheel and observed minor cupping on right front tire. After getting home and unloaded, took motorhome to get routine service done, including oil change, filters, and chassis lube. After getting chassis lube done and heading to Cummins shop 7 miles away, the minor shimmy became severe! At slow speed, nothing detectible but once getting up to 45 MPH, steering wheel suddenly wabbled severely until I dropped speed back down to 35 or so. Then after gradually returning to 45, all was fine until I hit a dip in road, and the severe shimmy started all over again.

A quick look under unit showed no visible sign of broken shock mount or steering linkage issue. Cummins looked it over but are not chassis people.

I now have it in a local truck service garage (no HR or Monaco dealer in area) but it may be a few days before they get someone on it.

Any thoughts on possible causes or things to be looking for? The Roadmaster chassis is not part of the recall with rear trailing arms.

[wolfe10]

Start by taking the coach to a tire dealer and checking RUN-OUT. Even if balanced, an "egg shaped" tire will not perform well.

Then, after verifying that run-out is less than .035", spin balance them on the rig.

If tires are badly cupped or worn, rotate the best two tires to the front and then check the new front tires for run-out and balance.

[hermanmullins]

You indicated that when you hit a bump you got a bad shimmy. Since it started all of a sudden it sounds to me like you may have a tie rod end or drag link problem. The tire problems that started before the shimmy indicates to me that your front end may have issues. Take the coach to a truck shop and have them inspect the front end for bent or loose links.

Herman

[john_harris]

Thanks to Brett and Herman for quick response and input. I will post what I uncover. As it happened so quickly, I can't help but think something broke.

[john_harris]

Still waiting to hear from suspension guy but reading further into the forum on tire issues has convinced me the original issue with cupping is with the Goodyear's and not necessarily the alignment. Tires have always been in conditioned garage when not on the road but still they are at 7 year anniversary of mfg date, so they should be replaced anyway. Stay tuned.

[huffypuff]

I have same issues With my 2006 HR Ambassador with the Goodyear tires. The reason I order Michelin so not to happen again. Guess what, same mileage as yours. I'm taking it to an alignment shop once those front tires are replaced but don't think alignment is the problem. The rear tires are not too far behind with right rear outer tire cupped like the front.

[desertdeals69]

Make sure the tires have the correct pressure for the load and it has the correct shocks.

[dickandlois]

Hi huffypuff, Welcome to FMCA,

Just wondering how many miles on the tires and there age?

Rich.

[huffypuff]

Rich and Lois,

I have almost 29,350 miles on this 2006 coach as second owner. I put 10,000 miles on it myself since I got it about a year ago.

After investigating more deeply I found I been running the front tires low on air and possible the rear since they have the same wear pattern.

The front tires are supposed to be 115 PSI and the rear 95 PSI. I was running 95 PSI front and rear and possible why I have more wear on the outside edges. I also noticed that the same size tires recommended by Michelin for my coach is a load range J not H as the Goodyear tires are.

That may be the second reason they worn more on the outside edges????

[john_harris]

Run mine at 105 on front and 98 on rear based on actual weights on each axle. My Goodyears show mfg date of week 14 of 06. I will be replacing front tires with new Michelin's as soon as front end work is complete.

[rob12345]

Looks like I have the same problem. I have 22,000 miles on 2007 Fleetwood with Goodyear tires. I put about 4000 miles on the coach my self.

When coming back on the last trip a couple of weeks ago, I noticed a slight wiggle of steering wheel. When I checked only the right front tire I noticed some cupping. The tires are 2006 so I probably need to replace them and get the front end checked. The coach never did seem level and always seems to want to go to the right except on flat roads.

Rob Sawyer, Fleetwood Providence, 40 ft, 2007.

[wolfe10]

Rob,

Welcome to the FMCA Forum.

Quite likely you have several different issues.

Start with checking RIDE HEIGHT. That will correct the level issue and can certainly have an affect on pulling/wander. You can get the specs from your chassis maker and/or chassis owner's club site.

And, with the new tires, have the front ones checked for RUN-OUT and then balanced-- preferably balanced on the coach.

Then a good alignment.

You have too much money in a coach like that to not have it a joy to drive.

Brett

[john_harris]

Alignment, ball joints, tie rods all checked out fine. Replaced Goodyears with new Michelins using the advantage program. All is fine and ride much better than when unit was new. Thanks for all who responded.

[donisme]

Yep had something similar. Tires wearing irregular, shimmy in the steering. Put new tires on, had it aligned. Found toe was off. Can not believe the difference in driving.

Don

[thomasturck]

I doubt with the relatively low milage that there are any worn front end parts on your vehicle. The severity of the shimmy you describe occuring at a relatively low speed sounds more like loose lug nuts than an out of balance or out of round tire.

An old mechanic