Coach plowing into right curves

[ramblinboy]

Got new Michelins on my coach and new shocks but it still plows into right hand curves. It feels like the front left tire is rolling on its sidewall - very unnerving. Anyone have this issue? Thanks

[DR60]

sounds like a camber problem. time to have the front aligned. DR

[bentjm]

Could be a lot of things. What coach and chassis do you have?

[twinboat]

Originally Posted by bentjm

Could be a lot of things. What coach and chassis do you have?

This one.

[Big-Foot]

Have you checked your -
* Air Pressures to be sure they’re what the tire manufacturer has on the sidewall?
* sway bar links and bushings?
* Front Shock Absorbers leaking, bushings loose?
* Control arm bushings?
* King Pin /or/ ball joints?
* Front end alignment?
* Rear end alignment (U-Bolts tight, etc)

[Flyer15015]

OP,
I've got the same chassis, but a different box on it.
First off, Michelins are famous / notorious for having soft sidewalls which contribute to "roll".
Second, you need to tell us what if any mod's you have done to the w-22 chassis.
Thanks to the research done by Yeloduster, I did the Ultra RV rear track bar and the modified Sumo's all round along with the gas charged Bilstein's.
I run Sailun tires @ 100# all round., and ya I get crap for tires made in Viet Nam, but I do like them. Got balance beads in all 6,and she rides like glass.
I drive mine like a hot rod, to the point that on winding roads I overdrive the corners and have to back her down.

Mike in Colorado

[1972VWbus]

Don't forget airbags in front coils. They hold air?

[Ray Lenning]

I agree with Gary have the alignment checked along with front end inspection.Our 05 W-22 had Michelins when we got it but have Toyos now and have not experienced what you have described . Be sure to weigh the coach and set the tire pressure to the recommended pressure from the Micheline chart .

[yeloduster]

Originally Posted by 1972VWbus

Don't forget airbags in front coils. They hold air?

There are no air bags in the stock front suspension of the W22. It has leaf springs. You are confusing it with the P30-P32 chassis.

[ramblinboy]

thanks all! Tire pressure at 110 all round Workhorse says 95. Im reluctant to soften a tire that feels like its giving way. Part of the problem maybe how its loaded going into the curve and not accelerating coming out - shifting weight to the rear of coach. This thing steers like a rabid squirrel with my previous whining Toyos and now this. Time for an alignment as you suggest.

[yeloduster]

Originally Posted by ramblinboy

thanks all! Tire pressure at 110 all round Workhorse says 95. Im reluctant to soften a tire that feels like its giving way. Part of the problem maybe how its loaded going into the curve and not accelerating coming out - shifting weight to the rear of coach. This thing steers like a rabid squirrel with my previous whining Toyos and now this. Time for an alignment as you suggest.

You really haven't told us much about your Chassis. I will assume it is a standard W22 and will have front GAWR of 8000# and rear GAWR of 14500# and has Michelin 235/80R22.5 tires. If we assume that you have not overloaded your motorhome then your front axle weighs 8000# or less and your rear axle weighs 14500# or less.

Using Michelin load inflation chart for a 235/80R22.5 tire with a load of 4000# (half of front axle GAWR) I get inflation pressure of 90 PSI for the front tires. Using the same chart with a load of 7250# (1/2 of rear axle GAWR) I get 85 PSI for the rear tires. If you have changed tires size the proper inflation for the GWAR's of your chassis will be about the same.

I think your tires are severely overinflated for the load. Overinflation can cause a multitude of issues, all of them bad. One of the bad things that overinflation can do is cause steering problems. Overinflation tends to make the tread of the tire bulge out in the center. This places less pressure on the outside of the tread making it easier to roll under.

As others have mentioned, you should get your front alignment checked. Workhorse did not include adjustments for Camber and Caster and therefore does not have a specification for either. From the factory Workhorse W series chassis have a caster of ≈+3°. Through experience MANY of us who own W series chassis have determined that the chassis steers much better if the caster is ≈+5.5°. Caster can be changed by adding wedges between the front axle and the leaf spring. Generally adding a 3° wedges under each front spring does the job. Changing the Camber would have to be done by bending the front axle. Not recommended and probably not necessary. Whatever it is is probably fine.

I would start by lowering your tire pressure to 90 PSI for the front and 85 PSI for the rear. You might find that with lower air pressure the symptom you describe will go away.

If you are still not satisfied with the steering find a shop that can add alignment wedges to your front axle and set the caster to ≈+5.5°.

[ramblinboy]

thanks very much for your comprehensive advice.
Im aiming to reduce air pressure all round.
Ill let you all know what the effects are when I roll again

[ramblinboy]

I dropped the pressures down and made a big difference in overall handling seems fuller contact with road surface was good advice thanks to all for your valuable input.