Steering Wheel Shimmy - Itasca Horizon

LK23 · 10-15-2009, 12:01 PM

I have an Itasca Horizon on a Freightliner Evolution IFS chassis. I have experienced steering wheel shimmy since my coach was new. Freightliner service has balanced and aligned the wheels. They also checked for run-out. I also had the Tru-balance wheel centering devices installed.

I now have 38,000 miles on my coach and have replaced the tires with new Michelins and have replaced the wheels with new Accuride aluminum rims. After many tire balancings (both lead and equal) and several wheel alignments I am certain it is not my wheels as I originally suspected. I called Freightliner their only suggestion was to check the front end for loose parts, tie rod ends, etc.

Any suggestions?

MrTransistor · 10-15-2009, 12:52 PM

Hi LK23,

Have you had the tires balanced on the vehicle? Could be that you have an out of balance hub assembly. You’d think that the Tru-balance would have corrected that but who knows. You could also try the ‘let all the air out of the tire to allow it to center on the rim then pump it back up’ trick. This has worked for me in the past with Michelins and allowed me to remove all wheel balance weights. Be sure to raise the front tires completely off the ground before letting the air out.

LK23 · 10-15-2009, 12:54 PM

Yes, I have had the tires "centered" on the wheels many times. Has no affect on the shimmy. I currently have equal in all the tires.

MrTransistor · 10-15-2009, 09:22 PM

Hi LK23,

I’m at a loss, perhaps a retired tire dealer can weigh in on this subject. Since run out has been checked and is okay, have you checked the wheel bearings for excessive play? The only other thing I can think of is tie rod ends. You don’t have enough miles for it to be bell crank. And the odds of it being the power steering unit would be pretty slim.

Rocket Heart · 10-17-2009, 09:57 AM

This may seem way off the wall but it actually happened to me. Similar circumstances - could not get a shimmy out of the front end - tried all you have and more - one mechanic spotted the problem (not a motorhome guy - he was a truck guy) - brake was rubbing just enough to make a shimmy but not enough to cause excess heat or wear - backed it off and presto change o no more shimmy.

LK23 · 10-17-2009, 10:23 AM

Thanks for the comments. I am still seeking suggestions. We are currently on the road and I plan to address this problem again when I have the oil changed next month.

Slapshottr · 10-17-2009, 11:50 AM

You need an alignment/suspension specialty shop. These shops only deal with alignment issues. Most shops who offer alignments don’t have the expertise to diagnose a problem. Anyone can hook up a computer and hit the return key. A truck alignment specialty shop is going to have the knowledge base and equipment to solve your issue.
I don’t know where your travels are taking you but in the Northeast Del Hatt Alignment is very good and does a lot of motor homes. They are located in Poughkeepsie NY.

LK23 · 10-17-2009, 11:13 PM

I am about as far from NY as you can get: California. We are based out of Denver, CO. I have had alignments performed at the local Freightliner dealer and the local Michelin dealer. I am not aware of any alignment/suspension speciality shops in Denver.

DAN L · 10-18-2009, 01:38 AM

Quote:

Originally Posted by LK23

Thanks for the comments. I am still seeking suggestions. We are currently on the road and I plan to address this problem again when I have the oil changed next month.

make sure that all the front end grease points are actually taking grease.

LK23 · 10-18-2009, 10:12 AM

Quote:

Originally Posted by DAN L

make sure that all the front end grease points are actually taking grease.

That's one I hadn't thought of. Thanks.

Pushrod · 10-19-2009, 09:23 PM

I have a Vectra 40 FD that occasionally has a slight shimmy on some roads. It usually occurs at constant speeds on level, smooth roads. It very gently shakes the steering wheel, and to me, it reminds me of some older fast cars I had that when you would really get on them, the front end would "unload" and shake the steering wheel. Each time it does it I thnk of the recall about the steering box, which I had checked out, and was told, "if it hasn't seized up by now, you're okay". That was almost 20K ago, and I haven't had a lock up in the steering, so I guess they were right. It hasn't been enough of a problem that I worry too much about, though. If you are ever in Grant's Pass, Oregon, have Henderson's Line Up check it out, they are good with frame/alignment issues.

LK23 · 10-19-2009, 11:11 PM

Pushrod,

Your problem sounds similar to mine. It happens about 80% of the time. On some road surfaces it goes away and ironically it is not a smooth, new road surface. It seems to lessen on roads with a smooth but gravel surface.

Papa_Jim · 10-20-2009, 12:56 AM

I don't know if this relates, but I experienced exactly your problem with a truck. Went through a lot of the things you have. Finally replaced the front axle shock absorbers, and the problem disappeared.

Capt Joe · 10-20-2009, 04:09 PM

I have a very similar thing going on with my W20 chassis Winnebago. At about 55 mph, steering wheel shake. Not too bad at slower speeds and it does vary with the road surface.

MH is in shop right now...Brakes for the 3rd time and WH is suppose to be replacing both rear calipers but it will be a week of so before they come in.....but I am taking it back to tire folks as soon as I get it back. Have Magnum PLus in the tires.

I am thinking about the Balance Master or the Centramatic devices as they say that they will 'cure' this problem. Anybody else used them?

Always-RVing · 10-20-2009, 05:23 PM

Front shimmy is almost always: Is this all the time or varries with speed?

So what causes shimmy and shakes in the front end? The biggest culprit is an out-of-balance or out-of-round tire. Vibrations, shimmy, and shaking felt in the steering wheel are usually not a sign of needing a front end alignment. An out-of-round tire or a bent wheel will usually produce a wobble or shimmy at all speeds, and replacement of the tire or wheel is usually the cure.

A vibration or shaking that is felt in the steering wheel only when the brakes are applied is not a front end alignment problem, but a brake problem.

LK23 · 10-20-2009, 08:49 PM

Batman,

While what you say may be true, I am convinced it is not related to my problem. I have new Michelin tires and new Accuride aluminum wheels. I have had the wheels balanced multiple times with no affect on the shimmy. I have had the tires rotated from front to back with no affect on the shimmy. It is not the tires or wheels.

DAN L · 10-20-2009, 09:06 PM

Quote:

Originally Posted by LK23

Batman,

While what you say may be true, I am convinced it is not related to my problem. I have new Michelin tires and new Accuride aluminum wheels. I have had the wheels balanced multiple times with no affect on the shimmy. I have had the tires rotated from front to back with no affect on the shimmy. It is not the tires or wheels.

did you grease the front end yet?
are you using KONI FSD shocks?
my moho had <8k miles and the original MONROE shocks were in bad shape. one front shock had no resistance, both rear shocks and the other front shock operated jerkily when removed.

the koni's made a big difference.

my grease fittings took a LOT of grease to get grease out of the joints and kingpins. i raised my moho with the hwh jacks and used jackstands for safety to get the weight off of the front suspension prior to greasing. grease and a grease gun are inexpensive. i use a harbor freight pneumatic grease gun and walmart moly chassis grease.

LK23 · 10-20-2009, 11:11 PM

Dan L.,

My chassis has been greased by the local Freightliner facility several times. I suspected the shocks and called Freightliner to inquire about the possibility. They told me that shocks would not cause a shimmy. Still wondering, but based on the efforts so for, I am convinced it is not the tires or wheels. Something related to the chassis must be the problem.

mfire1339 · 10-20-2009, 11:28 PM

LK23,

A year or two ago one of my old fords seemed to have a slight shimmy I hadn't felt before. Well after changing tires and wheels from another of my cars It was still there. Turned out to be a brake rotor machined off center. All the weight was on one side of the rotor causing extreme out of balance rotor. With wheels off I pushed the brake pads away from calipers and rotor would roll to heavy side. I had replaced the rotors a few months before but didn't notice the shimmy as I was testing the carpet under the gas pedal. Just a thought.

Mike

Rocket Heart · 10-21-2009, 08:21 PM

Quote:

Originally Posted by Batman_777

Front shimmy is almost always: Is this all the time or varries with speed?

So what causes shimmy and shakes in the front end? The biggest culprit is an out-of-balance or out-of-round tire. Vibrations, shimmy, and shaking felt in the steering wheel are usually not a sign of needing a front end alignment. An out-of-round tire or a bent wheel will usually produce a wobble or shimmy at all speeds, and replacement of the tire or wheel is usually the cure.

A vibration or shaking that is felt in the steering wheel only when the brakes are applied is not a front end alignment problem, but a brake problem.

If it were that simple everyone would be able to fix that problem right away. But, as we all know, shimmy's can be caused by a variety of related problems, the ones mentioned are only the obvious and he clearly had tried all that.

As I mentioned in my previous post mine was not at all one of those problems.