Wandering...ever so slight

[Motor7]

Ok, when I bought the rig the front end vibrated and I could feel every expansion crack in my fillings....but it did not wander at all. New Bilsteins all around, along with Sumo's front and rear. Tires were 9 years old, so I had Toyo M143's put on and an alignment done. Air pressure from the tire place was 110 cold. I have dropped it to 100 with maybe a slight improvement.

Then I added a Safe T Steer, not to fix the wander, but consider it helpful in a blow out situation. The wander is very slight, but it bugs me and I would like to get it gone. I have not weighed the rig yet, but I know it will be well under max since we just don't carry a bunch of "stuff"(besides throwing out the overhead 800lb tv had to help).

Alignment shop used Beeline equipment and he said he set the caster at +6, but did not tell me what the Toe-in was. I will call them back and confirm the setting, but in the mean time should I drop the tire pressure any more? I really do not think I need a track bar(s) since with the old tires and set up it did not wander.

The ride is a 100% improvement over rough road/expansions/etc. Sway is gone, but what I feel now is Yaw...let me explain. In a curve, and especially going downhill in a curve, if I say change lanes to the inside of the curve I can feel the Yaw and I can actually feel the rear of the coach kinda swing around to the outside of the curve. It's not dangerous or excessive, but it's there and it should not be there. I think the Yaw is directly related to the wander........?

I have all winter to sort this out, so FIRE AWAY!

[Charlie 5320]

Originally Posted by Motor7

Ok, when I bought the rig the front end vibrated and I could feel every expansion crack in my fillings....but it did not wander at all. New Bilsteins all around, along with Sumo's front and rear. Tires were 9 years old, so I had Toyo M143's put on and an alignment done. Air pressure from the tire place was 110 cold. I have dropped it to 100 with maybe a slight improvement.

Then I added a Safe T Steer, not to fix the wander, but consider it helpful in a blow out situation. The wander is very slight, but it bugs me and I would like to get it gone. I have not weighed the rig yet, but I know it will be well under max since we just don't carry a bunch of "stuff"(besides throwing out the overhead 800lb tv had to help).

Alignment shop used Beeline equipment and he said he set the caster at +6, but did not tell me what the Toe-in was. I will call them back and confirm the setting, but in the mean time should I drop the tire pressure any more? I really do not think I need a track bar(s) since with the old tires and set up it did not wander.

The ride is a 100% improvement over rough road/expansions/etc. Sway is gone, but what I feel now is Yaw...let me explain. In a curve, and especially going downhill in a curve, if I say change lanes to the inside of the curve I can feel the Yaw and I can actually feel the rear of the coach kinda swing around to the outside of the curve. It's not dangerous or excessive, but it's there and it should not be there. I think the Yaw is directly related to the wander........?

I have all winter to sort this out, so FIRE AWAY!

You sure he said +6? I have mine set to -6 caster. My coach was -2.5 and I had to fight it some, so I bought some shims and added a trac bar, much better now. Every thing I have read says you need negative caster not positive.

[Motor7]

No, I'm not positive, but I also thought I remember reading here on another thread that +5 was the minimum preferred caster for the Workhorse......?

[CJ7365]

Originally Posted by Motor7

Ok, when I bought the rig the front end vibrated and I could feel every expansion crack in my fillings....but it did not wander at all. New Bilsteins all around, along with Sumo's front and rear. Tires were 9 years old, so I had Toyo M143's put on and an alignment done. Air pressure from the tire place was 110 cold. I have dropped it to 100 with maybe a slight improvement.

Then I added a Safe T Steer, not to fix the wander, but consider it helpful in a blow out situation. The wander is very slight, but it bugs me and I would like to get it gone. I have not weighed the rig yet, but I know it will be well under max since we just don't carry a bunch of "stuff"(besides throwing out the overhead 800lb tv had to help).

Alignment shop used Beeline equipment and he said he set the caster at +6, but did not tell me what the Toe-in was. I will call them back and confirm the setting, but in the mean time should I drop the tire pressure any more? I really do not think I need a track bar(s) since with the old tires and set up it did not wander.

The ride is a 100% improvement over rough road/expansions/etc. Sway is gone, but what I feel now is Yaw...let me explain. In a curve, and especially going downhill in a curve, if I say change lanes to the inside of the curve I can feel the Yaw and I can actually feel the rear of the coach kinda swing around to the outside of the curve. It's not dangerous or excessive, but it's there and it should not be there. I think the Yaw is directly related to the wander........?

I have all winter to sort this out, so FIRE AWAY!

Before messing with your tire pressure I would go fill up your RV with all your crap, then go weigh it.

Look on the Toyo tire pressure chart, I attached the PDF file below, and adjust tire pressure accordingly.

I would also think your wandering is now because of the alignment done.

You stated that it did not wander before. So I would take it back to the alignment shop, and "show" them how it wonders.


What was the reason for getting the alignment done? Did the 9 year old tires show uneven wear?

[Motor7]

CJ, no they did not show any wear. Matter of fact the tread looked brand new on all 6, but the sidewalls were cracking pretty good. It is a new to me coach, so I thought it would be a good idea to do the alignment along with new tires...yep, might have been a bad decision.
I tend to agree that the alignment caused this issue which is why I am reading everything I can on the alignment specs. Toe in recommendations are from 1/8th to 3/16's so before I do anything I am going to find out where they set the toe.

[CJ7365]

Originally Posted by Motor7

CJ, no they did not show any wear. Matter of fact the tread looked brand new on all 6, but the sidewalls were cracking pretty good. It is a new to me coach, so I thought it would be a good idea to do the alignment along with new tires...yep, might have been a bad decision.
I tend to agree that the alignment caused this issue which is why I am reading everything I can on the alignment specs. Toe in recommendations are from 1/8th to 3/16's so before I do anything I am going to find out where they set the toe.

Here is a pretty neat diagram explaining all the adjustments.

IMO I do not believe the toe in/out is causing your problem.

I would go back and have them put the caster at the original measurement.


Wheel Alignment




Looking through another thread looks like 5 degrees would be max, and factory spec was 2-3 degrees


http://www.irv2.com/forums/f22/w22-w...ecs-66111.html

[Charlie 5320]

Originally Posted by Motor7

No, I'm not positive, but I also thought I remember reading here on another thread that +5 was the minimum preferred caster for the Workhorse......?

I gave some WRONG info. Mine is set to +6, don't know what in the world I was thinking. Top of the axle is set 6 degrees behind the bottom of the axle measured at the king pin.

[fun 33V]

When I had Toyos installed they wandered for the first 500 miles then they settled down after weighing, 85 psi all the way around made for a pretty good ride.Made several other suspension mods been very happy with

[Motor7]

Charlie, usually if it was over 15 min ago I already forgot it or remember it all wrong

Fun, thanks....... I have around 300 mile son them and will run across some scales soon. I will experiment with lowering the pressure before doing anything...uhmmm expensive. Although, I was perusing Omey's site and building a rear track bar really looks like fun(My MIG needs exercise). I have the tools and ability, so for $50-60 it would be a nice addition.

Cj, thanks for the informative links............!

[Arch Hoagland]

Originally Posted by fun 33V

When I had Toyos installed they wandered for the first 500 miles then they settled down after weighing, 85 psi all the way around made for a pretty good ride.Made several other suspension mods been very happy with

A friend of mine drives for one of the largest trucking companies in the U.S. He said when he gets all new tires on his tractor it gets just a bit squirrelly until he puts several hundred miles on it.

[tmw188]

Originally Posted by Motor7

Ok, when I bought the rig the front end vibrated and I could feel every expansion crack in my fillings....but it did not wander at all. New Bilsteins all around, along with Sumo's front and rear. Tires were 9 years old, so I had Toyo M143's put on and an alignment done. Air pressure from the tire place was 110 cold. I have dropped it to 100 with maybe a slight improvement.

Then I added a Safe T Steer, not to fix the wander, but consider it helpful in a blow out situation. The wander is very slight, but it bugs me and I would like to get it gone. I have not weighed the rig yet, but I know it will be well under max since we just don't carry a bunch of "stuff"(besides throwing out the overhead 800lb tv had to help).

Alignment shop used Beeline equipment and he said he set the caster at +6, but did not tell me what the Toe-in was. I will call them back and confirm the setting, but in the mean time should I drop the tire pressure any more? I really do not think I need a track bar(s) since with the old tires and set up it did not wander.

The ride is a 100% improvement over rough road/expansions/etc. Sway is gone, but what I feel now is Yaw...let me explain. In a curve, and especially going downhill in a curve, if I say change lanes to the inside of the curve I can feel the Yaw and I can actually feel the rear of the coach kinda swing around to the outside of the curve. It's not dangerous or excessive, but it's there and it should not be there. I think the Yaw is directly related to the wander........?

I have all winter to sort this out, so FIRE AWAY!

100 psi sounds too high for your rig. Is it a W22 and only 32' I'm thinking 80-85 may be closer to what you might need. I have TOYO's on a W24 37' and 85 would be real close but I'm running 90psi in all.

[Charlie 5320]

Originally Posted by tmw188

100 psi sounds too high for your rig. Is it a W22 and only 32' I'm thinking 80-85 may be closer to what you might need. I have TOYO's on a W24 37' and 85 would be real close but I'm running 90psi in all.

Good catch on the PSI. My coach weighs 19600 and according to Yokohamas web page with my axle weights 80 PSI, so that's what I run.

[tmw188]

Yeah that's just too much and probably part of the problem.


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[Davel]

I just put Toyo's on my W-22 and it seemed to wander a little at first on our trip from Indiana to Florida. I didn't notice it so much later in the 1200 mile trip. My tire pressure is in the 75-80 range. The tires handled very well in the rain and one panic stop.
The caster setting is correct at 6 degrees. The national service director for Workhorse told me to increase it several years ago. It helped take the last little bit of wander out of it, now it wants to go straight.
The track bar is a good addition and making one would be fun. I bought mine and could have saved money...but I procrastinate.

Good luck,
Dave