Wandering, sway bars, alignment, ride height, oh my!!

[YC1]

I had the STS on my coach for many years. The pull to the right was there before the install and is still there after its removal.

With the terrible wandering it had, sawing the steering wheel back and forth against that blue monster wore me out and 300 miles a day was enough.

Van, how about building a bracket to attach to the rear lug nuts that would hold a lazer light?? I think that is basically how it is done anyway. Remove two opposing lug nuts, put the device on the lug and bolt down. ??? Problem solving 101, throw crazy ideas out and let everyone build on them.

[YC1]

How do we know the front end thrust angle is correct??

[Kurt Averill]

I wish I could say I've never done that... The good news - it is driving the way you want it to - if you can solve the tire wear mystery your goals will be met. I always try to start at zero with an issue - everything adjusted and pointed in the right direction - and most of the time that gets us where we want to be; on the other hand, sometimes we just have to give them what they want. In a race car ( drag car ) we almost always have to pre-load or adjust the suspension from "neutral" to get the car to launch and drive straight. Some cars, especially really high powered stuff sometimes need a little rear steer to go straight. So - within reason - you give them what they want to get the result you want - and if that isn't geometrically perfect - so be it.
My understanding of the STS ( I hate typing it too!) is that its major function is as a steering damper in the case of a blow out, and to a lesser degree to help keep things headed straight - maybe as a bit of a crutch for a sloppy steering box or whatever. With a little adjustment mine seems to be fine - I'll be curious to see what your opinion is after running without for a bit, maybe I'll try it too.
It would be nice if someone could get a visual on the coach from behind as you are driving down a straight stretch to see how it looks, see if it appears to be "crabbing" or looks nice and straight.
When I did the bushings and extra panhard bars in mine, I did the front first. ( I had my reasons ) After the front was done, going straight down the road went from being pretty much straight on the steering wheel ( on average ) to about 30* off. After I did the rear bushings and bar - it went right back to where it started - never had to adjust it.

[nodine]

Van,

Glad you got the coach out and no longer have the pull. I know it will haunt you until you know which change effected the cancellation of the pull. I have not been back on irv2 since early yesterday so just saw your post. You are most likely on the road now or stopped for the night. I doubt you are taking I-40 due to the time of year, but if you are and passing thru Knoxville, give me a call and we can meet for a short visit.

Bob

[Vanwill]

Originally Posted by nodine

Van,

Glad you got the coach out and no longer have the pull. I know it will haunt you until you know which change effected the cancellation of the pull. I have not been back on irv2 since early yesterday so just saw your post. You are most likely on the road now or stopped for the night. I doubt you are taking I-40 due to the time of year, but if you are and passing thru Knoxville, give me a call and we can meet for a short visit.

Bob

Thanks for all the suggestions from you veteran gearheads. I’m in northern FL now, at Tom and Paula’s. After that long drive from Pinehurst, NC to Hawthorne, FL, I can conclusively say that the pull to the right is NOT gone. It requires much less effort to turn the steering wheel to the 30* left position to counteract the pull to the right, and it will no longer DART off to the right, but probably the same thing that caused the pull to the right is still there. The only change may be simply that the STS centering spring is no longer making that 30* left correction require as much effort.

Yes, Kurt (and others), I’m searching for some other solution. Perhaps it is front axle alignment. I will have to figure out a way to confirm that.

Thanks for all the effort from you guys. I’m still searching…and still baffled.
Gearheads! Meet me at Q! Myron, have you left yet? 😊

[nodine]

Originally Posted by Vanwill

Thanks for all the suggestions from you veteran gearheads. I’m in northern FL now, at Tom and Paula’s. After that long drive from Pinehurst, NC to Hawthorne, FL, I can conclusively say that the pull to the right is NOT gone. It requires much less effort to turn the steering wheel to the 30* left position to counteract the pull to the right, and it will no longer DART off to the right, but probably the same thing that caused the pull to the right is still there. The only change may be simply that the STS centering spring is no longer making that 30* left correction require as much effort.

Yes, Kurt (and others), I’m searching for some other solution. Perhaps it is front axle alignment. I will have to figure out a way to confirm that.

Thanks for all the effort from you guys. I’m still searching…and still baffled.
Gearheads! Meet me at Q! Myron, have you left yet? 😊

Van,

Since you are at Tom and Paul's it looks like a straight shot on I-10 to Q.

Myron, you could tag along with Van. I can confirm that he is a good travel buddy.

Bob

[pwhittle]

Myron,

If you can stay close to Van's motor home, you will be able to hear his new sound system going down the road too! Hope you like Blues Guitar Legends!

[alank]

Originally Posted by Vanwill

Thanks for all the suggestions from you veteran gearheads. I’m in northern FL now, at Tom and Paula’s. After that long drive from Pinehurst, NC to Hawthorne, FL, I can conclusively say that the pull to the right is NOT gone. It requires much less effort to turn the steering wheel to the 30* left position to counteract the pull to the right, and it will no longer DART off to the right, but probably the same thing that caused the pull to the right is still there. The only change may be simply that the STS centering spring is no longer making that 30* left correction require as much effort.

Yes, Kurt (and others), I’m searching for some other solution. Perhaps it is front axle alignment. I will have to figure out a way to confirm that.

Thanks for all the effort from you guys. I’m still searching…and still baffled.
Gearheads! Meet me at Q! Myron, have you left yet? ��

Vanwill, I've been following your problem of a heavy pull to the right and have a couple of questions.

Do you know the weight on each front tire?
Do you know what caster setting you currently have on each front tire?

If you have a heavy left front tire and are running a high caster setting, that can cause a significant pull to the right.

[deSanford]

My .02 cents of advice may not be worth anything, but it is FREE. I have had a big blue shock "STS" installed on my last two motor homes with excellent results. On my Navistar Monaco I had Wayne of Roadmaster install a kit I purchased from Henderson's RV. It is their adjust on the "FLY" unit for the STS. I have successfully used it when the crown of the road would pull one way or the other, also when the wind blows on the side of the coach and I'm holding the steering wheel to counteract that pushing I just flip a small toggle switch on the Henderson's unit mounted by my leveling system. That basically holds the STS in position so I can relax my arms holding the wheel so I'm going straight.
Of course if I have a BLOWOUT on my front tire it should hold things somewhat so I don't end up in the gutter. Hope to see everyone in "Q" as we will hopefully arrive on the 22nd of January. We will have a POT LUCK on the 24th. Wood for the fire and tables for the P L is appreciated. Don't forget the cookies and beer for the FABULOUS helpful neighbors. A propane saftety talk will also be on the 24th before the "P L". Drive safely and keep the greasy side down.

[YC1]

Originally Posted by alank

Vanwill, I've been following your problem of a heavy pull to the right and have a couple of questions.

Do you know the weight on each front tire?
Do you know what caster setting you currently have on each front tire?

If you have a heavy left front tire and are running a high caster setting, that can cause a significant pull to the right.

I am not Van but have had the pulling forever too.

Here are my results if you can make some sense of it.

[Vanwill]

Originally Posted by pwhittle

Myron,

If you can stay close to Van's motor home, you will be able to hear his new sound system going down the road too! Hope you like Blues Guitar Legends!

Slow, deep, LOUD, soulful blues guitar music is wonderful! There are even a handful of white guys that do it very well, although I think the "Blues Guitar Legends" accolades belong primarily to the black pioneers of Blues. Thanks, Paul!!

Just need to work out something to 1) quickly and SURELY mute it to take a walkie-talkie call, and 2) a better microphone, or microphone placement, for the hands-free phone calling. The remote works "sorta" to mute things, but is not reliable. Using the radio for hands-free makes it possible for me to hear the caller VERY well, but they say they have difficulty hearing and understanding me.

Overall, I'm extremely happy with the new system and all the choices you made for me, Paul.

[alank]

TC1, looking at your alignment results, camber usually isn't something that's adjustable. They moved your toe from.07 to 1.1 degree, I like .04 total. That gives just a little toe, but keeps the front tires pointing the same direction down the road. Your 1.1 is still probably about in the 1/16" area ( don't know the diameter of your tires) so it isn't really that bad.
The caster they took from 2.8 and 4.1 to 5.7 degrees. They say the spec range was 5 to 7, the spec range on my freightliner is 4 1/2 to 6 degrees (+ 1/2 on right wheel), so they are coming down. I have noticed the caster spec on the F53 has also been decreased in the recent years so they seem to be coming toward my way of thinking.

I would expect your coach to be a bit more difficult to drive and get pushed around by the wind more. A high caster setting helps the front wheels of vehicle you are towing track the direction the hitch nudges the front end of the car, and that's a good thing. However, you don't want the front end of the coach to move easily with a nudge of the wind and a low caster setting will help here. The + 1/2* caster above will tend to make the steering turn left to help compensate for road crown. If your coach still wants to turn right, the right tire needs to be even more positive than the 1/2*.

High caster settings will also turn the steering towards the front tire with the least weight load. Consider a blowout, the left tire goes down instantly throwing the majority front end load on the remaining good right tire making it turn to the left. The lower the caster setting, the less severe the turn will be. We've read on the forum about some reported blowouts being very hard to control, and others that reported a blowout to be a non-event, just steer it off to a stop.

I approach a caster setting in terms of how much trail you want to run. Trail is measured , in inches, where the rubber meets the road and isn't something very many alignment techs know about. You project a line through the steering axis to the ground, the project a vertical line through the axle center to the ground, the distance between is the trail. When you determine the trail you want to run, you then calculate the caster setting needed on your diameter of tire. For instance, my CR-V runs about 1" of trail on a 27" tire. To get 1" of trail on a 40" tire takes much less caster. Have you ever herd the comment, Wish my coach drove like the toad drives.? Well, try setting the coach alignment up like the toad's aligned. The caster doesn't get set at, say 5* because something else was set at 5*. Set the caster according to what's needed to attain the amount of trail you want. I think most motorhome alignment settings come from truck settings because motorhome chassis just grew from truck chassis. Trucks don't have a large side surface area around the steer wheels so high caster settings don't have the negative effect it does on a coach.

On my coach my caster ended up at about 2 1/4* and produced about 3/4" of trail. On a solid axle the adjustments are made with shims with 1/4* increments so perfection isn't possible, you just get close. They didn't get the 1/2* on the right front wheel so I have a slight right pull. It can be easily held with one finger so if you drive with one or both hands on the wheel, it's hardly noticeable and in the left lane, usually isn't there at all. The other thing you'll notice with a low caster setting is that the steering wheel is easier too turn. It just takes less effort to steer the coach, in town or on the highway. I quite often turn corners in town with one finger in the wheel or just the palm of my hand on the top of the steering wheel.

I've had two F53 chassis aligned this way and they were a pleasure to drive. Getting it done at the Freightliner shop was a bit more difficult mostly because the tecs didn't agree or understand it and didn't want to align to my specifications, partly because the axle and air bags had to come off to install longer bolts for the shims.

Any trials for corrections will have to be done with nothing in the way of stabilizers attached to steering components. I've never used any on mine.

[Vanwill]

This pull to the right has me baffled, but I'm sure I'll find the cause of it. Although something like the Blue Ox adjustable unit would "cover up" the problem, I have no interest in a solution like that.

It is a vehicle. It's a large one, but it's still a vehicle, and with a relatively unsophisticated suspension/steering design. It can be made to go straight without pulling, using only what is already installed on the vehicle. I just have not found the answer yet...but either *I* will or *WE* will. There are some really resourceful folks that have contributed to this thread.

If you want to try to understand my confusion about this issue, remember that I had my alignment checked by a local shop that tolerates (perhaps even enjoys dealing with) my idiosyncrasies. Using their late model laser alignment equipment, they showed me that my front end needed NOTHING--it was well within specs. And that my rear end was indeed misaligned, but within specs--1/16" or less. Fast forward, and I have decreased the length of the two rear trailing arms on one side a full 1/2" and the pull to the right is still approximately the same. Removing the STS allowed using much less effort to keep the steering wheel clocked about 20 - 30 degrees left to counteract the pull to the right, but to go straight, the wheel is clocked to the exact position as before changing trailing arm length or removing the STS. So the centering spring in the STS was probably causing so much effort to be required to clock the wheel to the left, but had nothing to do with how much the wheel had to be clocked to counteract the pull to the right.

And bear in mind that I don't just want a "fix", I want to understand what caused the problem in the first place. There is a reasonable answer. We will find it. Thanks for all your thoughts and help.

[10Boomer]

Originally Posted by YC1

I am not Van but have had the pulling forever too.



Here are my results if you can make some sense of it.

Makes sense to me Myron. You have right lead castor at your front axle. Looks like they thought it was to much lead originally? Everything else looks similar. I’m going to check on the rear to from numbers. Need to review with mine.