Born Free Leap'n Lions RV Club

Hi all,

We are noticing significantly more sway on our RV (2004 26RSB) after we had new tires installed ( Michelin lt225/75/r16) . The previous owner has also installed super steer friction bar installed . What could be wrong ? Any help is greatly appreciated

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Senthil & Sam
2004 26 RSB

What brand tires did you have on there previously? The biggest things that comes to mind for me are alignment and tire pressures. Assuming the alignment didn't change then you might experiment with tire pressures. Start by comparing the current pressures with the recommended pressures.

What is a friction bar? Do you mean sway bar?

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Russ and Denise
2002 24RB

Describe what you mean by "sway" please. That has a specific meaning in the trailering world, but I'm not sure what context you're using it in with a motorhome. If you can describe the symptoms more specifically it might lead to a better long-distance diagnosis.

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'06 Born Free 32 RQ Kodiak Chassis
(Former: '01 Born Free 23 RK)
Dinghy: '16 Jeep Wrangler Rubicon with a Blue Ox Aladdin tow bar.
Traveling with Sir Winston and Lady Rae (Cavalier King Charles Spaniels)

Szkumar,

Also, did the shop that installed your new Michelin tires change anything in the front alignment?

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Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad

The replacement tires.... are they exactly the same tire that was removed? Load range (very important ) thread design AT,MS,AS, or highway . Sidewall rating , usually goes along with load range .

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2012 25' rb

First of all thank you all for your help.

We had Michelin XPS tires before , we replaced them with Michelin LTX M/S2 tires. We are noticing that every time a semi truck overtakes us or when there is a gust of wind, we feel like we are getting pushed off the road. We had no such issues before we changed the tires .

We had the tires changed through a ford dealership, not sure if they changed any alignment ( that was going to be my next stop, to find out if they changed anything) . The tires pressure is as maximum recommended for the tires, 65 for the front and 80 in the rear, though we were not at maximum load.

Yes, I meant sway bar

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Senthil & Sam
2004 26 RSB

Interesting, I have the exact same tires and I've played around with tire pressures some with little affect. I'm still running stock sway bars and thinking of upgrading to bigger bars or maybe start with poly bushings in place of rubber. I have found that I have some issues with sway as weĺl, but since I have nothing to compare with its hard to tell. I've owned it one year and the alignment was done just before purchase along with the new tires. Mine also has new Bilstein shocks and I don't concider the sway bad, but would like it improved somewhat. What makes each coach different is how we load it, drive it, etc. Finding that sweet spot for balance and stability can be a challenge and I'm still learning since all my experience in the past was towing travel trailers.

FYI, the sway I mentioned is really what I concider stability in cross winds, semi's passing etc. In general during calm winds and light traffic I don't really have any issues.

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Russ and Denise
2002 24RB

I'v got a Kodiak cut-away chassis coach which are world-renowned for being frightening to drive when they came out of the factory. I did a number of things, suspension-wise, to make it tame on the highway. Usually, the Ford e-chassis vans are much more civilized though.

First, the recommended tire pressure for your coach is likely lower than the maximum tire pressure for the tires. That will make a difference in the way your coach rides.

You'll want to make sure that the tires that the dealer installed are weight rated the same as the tires you had taken off. Just because the dealership installed them, and they're the right tires for a normal van doesn't necessarily mean that they are the right tires for this application. Sidewall stiffness is important to the handling of a heavier vehicle. It might be interesting to know if the sidewall rating on the new tires is the same as the old ones.

If all that checks out, I'd recommend that you look at your shocks. If they're still the factory shocks, and you have more than 15,000 miles on them, they're probably shot. Look at Bilsteins or Konis as replacements.

Last, depending on the age of your coach, have all of the anti-sway bar bushings and your air bag suspension (if equipped) checked. If you don't have a rear anti-sway bar installed, this might be a good opportunity to consider that. They can make a huge difference in body-roll which, of course has an effect on steering. If the issues persist after all that, it may be worth installing radius rods on the rear axle as well to further limit the amount of "rear-axle steering" you might be experiencing.

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'06 Born Free 32 RQ Kodiak Chassis
(Former: '01 Born Free 23 RK)
Dinghy: '16 Jeep Wrangler Rubicon with a Blue Ox Aladdin tow bar.
Traveling with Sir Winston and Lady Rae (Cavalier King Charles Spaniels)

The xps tire is a steel cased retreadable highway rib tire . The LTX probably lacks the same sidewall stiffness of the xps and it has a more open tread design which might allow the tire to give more (squirm)on the pavement .

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2012 25' rb

Szkumar,

I think randallrae has identified the cause of your sway complaint. The previously installed Michelin XPS Rib tires have very stiff steel cords in the sidewalls. These tires were primarily intended to be used on delivery vehicles that routinely may run up against curbs in city streets. The sidewalls on Michelin LTX tires use fabric cords that are not nearly as stiff causing the tire to allow more sideways motion under varying side loads.

One way to reduce steering instability or wander is to have the front end alignment caster set to a value near the high end of the spec range - setting caster to at least +5 to +6 degrees should help the problem.

Learn more about the XPS Rib tire at this Tire Rack website link: http://www.tirerack.com/tires/tires.jsp?tireMake=Michelin&tireModel=XPS+Rib

Note that this tire is recommended for summer use only - not recommended for winter driving. The E350 and E450 chassis now comes from the Ford factory with Michelin LTX tires as original equipment. One thing you should have noticed is that your coach now equipped with the LTX tires should have a somewhat softer ride than previously with the XPS Rib tires.

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Bill Hemme - Spencer, Iowa
E-mail: whemme@earthlink.net
2002 Born Free (Ford E-450 V10) 26' RSB
2016 VW Golf GTI - toad

Thank you everyone for your suggestions and help, we will try out the suggested fixes and update you guys in the next few weeks

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Senthil & Sam
2004 26 RSB

I installed a rear trac bar it helped a lot http://www.supersteerparts.com/products ... assis.html

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2012 25' rb

When a bushing failed on my front sway bar I replaced the stock bar with a Hellwig bar. This was a definite improvement. The general consensus is that adding positive castor is the first thing that should be tried.

Here's a link to a thread on RVForum.net:

http://www.rvforum.net/SMF_forum/index.php/topic,78950.0.html

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Tom
2005 24' RB
Towing 1978 VW Bug convertible
New Hope, MN

Hi guys, as on update, I took our vehicle back to the dealer to take a look at the issue. They said the front wheels alignment was messed up. They realigned my front wheels. I have not tested it at highways speeds much, but the handling seems much better . Will keep you posted after driving on the highways a bit more .thank you again to all those that chimed in and helped us.

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Senthil & Sam
2004 26 RSB

Just FYI
I've used both tires. I agree with previous posts - the steel sidewall tires will give you a more firm ride than the lighter weight tires. There can be more "sway" with the lighter tires especially in coaches that may be near their max payload weight.

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Bornfree (1999 Rear Kitchen)
Traveling with Chester (The Boxer) - at least in spirit