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

[walt2137]

Originally Posted by walt2137

Just go back to the forum page and do a search on wandering, sway bars

Well dang we are on it, duh!

[wigginsjsr]

I added a Blue Ox TruCenter to my 2011 Knight. Solved 98% of steering problems.

[rebelcarm]

I added the Roadmaster Relex it helped big time.
rebel

[rebelcarm]

That should be Roadmaster Reflex steering stabilizer, from etrailer MO. Great place to deal.
rebel

[Vanwill]

Well, guys, I apologize for abandoning this thread. Life gets in the way sometimes. The good news is that my coach is 100%, tee-totally and completely cured of every last smidge of wandering. It tracks like it’s on rails, and passing semi’s sometimes are not even noticed until I see them in the side window. I drive with two fingers now, and can look off the road at the scenery, tune the radio, or get a drink. This is not one of those “I think it is fixed now” or “It’s so much better” things. It is CURED. Period.

Perhaps even better news than that is that I think I can do exactly the same for any other wandering Roadmaster RR8S product, especially if 90's vintage. I have not verified that, but I’m willing to try out my “fixes” on a few “Guinea Pig” coaches. I have one lined up already. I can also report that a friend with a 1991 Dynasty 31’ has also cured his wandering using similar alterations, so we can dispel that myth that “short coaches cannot be made to handle well”.

Also, one of our frequent contributors to this thread, Jim from Canada with a 96 Dynasty, has cured his coach of wandering and is very happy with the "no doubt about it" results. I hope he will post later.

You all know my posts tend to be long, and this one will be no different, but I’ll try to summarize what I’ve done and keep it as short as possible. The following is the chronology of what I’ve done from the very beginning to date. I wish I had taken the time to make one incremental change at a time. That would have been the scientific method, and would have lent more credence to the results, but they are what they are.

1) When I first got the 1993 Dynasty 36, it wandered badly. It felt as if the steering wheel was connected to the steering tires with Jello.

2) Checked for loose steering components and found nothing (88K miles). Checked the steering gear end play adjustment (TRW adjustable gear) and made a very noticeable improvement by eliminating that play. It did not cure the wandering, per se, but it made it easier to control it.

3) New Michelin XZA3+ 11R22.5 tires. No difference.

4) Changed shocks to the Bilstein "comfort" shocks, since it was suggested by many “experienced” Monaco mechanics. They did improve the handling of the coach. They did improve the ride. They did NOTHING for the wandering.

5) Purchased (4) ATRO bushings from Rupparts dot com. I changed both front and rear Panhard rod bushings (using the ATRO bushings), and got a DRAMATIC improvement. UNQUESTIONABLY the single greatest improvement so far. Coach was almost a one-hander.

6) Changed out ALL the trailing arm bushings for the ATRO bushings. That improvement was undeniable, but strangely less dramatic than changing the Panhard rod bushings. The coach was now a "one hander" for certain. ALL the original bushings I changed out were in EXCELLENT condition—they were just too soft to do the job.

By that time, I was really quite happy with the handling. But repeating the “tail wag” test, with a long piece of 2” tubing inserted into the hitch receiver and “rowed” by two helpers had convinced me that even with all the new bushings, the REAL problem was still there—that the H-frame was not sufficiently stabilized by one Panhard rod. The stiff bushings were just masking the problem to the point that it was almost insignificant. I confirmed that by taking the coach out on a lonely, straight two-lane road and making violent back-and-forth lane changes, simulating what you might do if you were dodging an obstacle in the road, then having to quickly return to your lane. When I did that, I could feel the coach “overshoot” when returning. I would never have had the nerve to try that before changing the bushings—I think I would have ended up in the ditch.

But I was still stuck with the fact that there simply was no room on my coach to add another P-rod. Then it occurred to me to triangulate the trailing arms with cross braces. You can see the attached pix to see what I did. The cross braces were made from 1/2" diameter mild steel bars with RH threads on one end and LH on the other, and Heim joints at each end, attached to small tabs welded on the trailing arms. After adding these cross braces, I repeated the rapid-lane-change road test. DRAMATIC difference! There was virtually NO overshoot when returning to my lane, and the entire excursion out and back seemed very well under control. I would liken the change to what I would expect from adding anti-sway bars, although I have no experience with that on the Roadmaster chassis. I took the coach on a 1600 mile round trip to FL and its handling was superb.

A few notes about the cross braces—I installed them only on the lower trailing arms, front and rear. There is much less room for them on the upper trailing arms, although it may be possible. I’m sure adding them to the upper trailing arms would also help, but just the bottom ones seem to have a dramatic effect by themselves. The tabs welded to the trailing arms are quite small, and if for any reason one wanted to remove the cross braces, there would be little left on the coach. Although I welded the tabs on when I had the trailing arms removed to replace bushings, they could easily be welded on while the arms were still on the coach. Lastly, on many coaches made after 1994, where the generator is on a slide between the front trailing arms, it may not be possible to add the cross bracing in the front. However, if one believed his coach required additional control for the H-frame in front, there appears to be room for a Watts Link arrangement on virtually any coach, although the installation would involve some considerably more difficult welding and more complicated parts. The Watts link would, however, be as theoretically correct and effective (perhaps more so) as the cross braces.

One more observation about the cross braces—I think I might have accomplished the same effect with ONE single cross-brace. SC3283 pointed that out to me. He said that if the single brace were large enough and sturdy enough to sustain a compressive load, the single brace would accomplish the same as the much smaller tension-only rods I had made. He was using a single brace on his race cars. If I were to do this again, I would try using a single piece of 3/4" black pipe (1.06 OD) with ends welded in to accommodate the Heim joints. Alas, since I last posted, I have bought a new-to-me 2000 Dynasty and the 1993 is for sale, so I may not get to try the idea out.

After all is now done, and I look back at the project, I would like to have done things differently, just for scientific curiosity. If I were starting over, I would install the single cross brace FIRST, just to see if its effect was as great as that of replacing the front and rear Panhard rod bushings. And I may yet get to try out the Watts Link in the front. For whatever reason, the 2000 Dynasty 36 that I bought has virtually no wandering. It has never had a steering gear adjustment and its original shocks, at 120K miles, are surely worn out. Go figure.

I will leave you with four things I’ve become thoroughly convinced of and hope they will be of use to you.

ONE—Most of your wandering originates in the REAR, NOT in the front. It is that heavy rear that is wiggling around the most.
TWO—Wandering is 90% the result of SUSPENSION components and design, NOT steering components and design. Your steering components must be tight, but even if they are, you can still suffer wandering.
THREE—Most important is to understand that if your coach wanders, it is for one and only one reason—IT IS GOING EXACTLY IN THE DIRECTION THAT ITS WHEELS ARE POINTED. Many folks tend to think that the “coach” wanders and the “wheels” follow. NOPE. It is the other way around. You have to be able to visualize what is happening if you reach down with a giant “hand” from above a coach traveling down the highway, and use that hand to “twist” the H-frame one way and then the other. THAT is the definition of what is happening during “wandering”. Think of the H-frame as the wheel truck of a skateboard.
FOUR—When someone’s complaint is a handling complaint that is NOT wandering, then alignment, tires, tire pressure, sway bars, ride height, steering add-ons (snake oil)—all or any one of those things might satisfy the person’s desire for a fix. But if it is wandering they are trying to cure, NONE of those things will have much effect in the vast majority of cases. That is not to say that someone, somewhere will not achieve a "cure". But for every coach "cured" by that choice, there will be two others who did exactly the same thing and got no improvement. You have to cure the root cause. People tend to feel “improvement” when they have spent a lot of money on something, whether it realistically cures the problem or not. The sure giveaway is when someone says, “I think it helped a good bit.” When they fix the REAL problem, they will say, “Holy crap! What a difference!! I can’t believe it!”

I would be more than happy to answer any questions, and to help any of you in any way I can. I thank each of you for your time and thought. This has been a very educational thread in many ways. If you happen to be in my neck of the woods near Pinehurst, NC stop and visit.

Van W 2000 Dynasty 36, and 1993 Dynasty 36 (seeking new home)

[sc3283]

Van, it is hard to believe its been almost a year since many of us began putting our heads together to find a TRUE fix...WE SUCCEEDED!!!

[Papa_Jim]

I have been unhappy with our coach since we bought it in 2008 because it has been a real bear to drive. I had attempted to solve this by doing all the obvious things, new tires, new shocks, adjust the ride height, tighten the steering box, a couple of alignments, new tie rods, new pitman arm ends, installed a steering stabilizer, etc. Nothing I tried solved the problem. The handling was vague. Most of the time the coach wandered all over the road. It handled better, even quite well, with an angled side wind pushing against the front right corner of the coach. It handled better, not good, but better when pulling the toad.

Then Van suggested the 'tail wag test'. When I tried that test, I was appalled! As the hitch bar was being pushed by a couple of friends, I crawled under the coach to see the coach frame swimming all over the place above the H frames! I realized then that the suspension bushings were the problem.

I purchased the Atro bushings from Rupparts, intending to change them myself. However, health problems intervened, and I couldn't do the work. This summer I finally had to admit that I could no longer drive this coach any longer. I had to solve the wandering problem with this coach, or get rid of the coach.

I employed the services of a good repair shop in our area to change the bushings. As the work progressed, I was very glad of this decision because it was very difficult work. All the rear bushing bolts had to be cut out with a disc cutter. The bolts were rusted in so badly that they were practically welded in the frame. I guess our Canadian road salt is to blame for that. All the bushings were replaced, along with brand new bolts.

When the job was done, I did the 'tail wag test' again. This time, the only movement was the tire sidewalls! We took the coach on a short trip (about 200 miles round trip). The change in the handling is absolutely dramatic! Our coach now drives exactly the way that I knew it always should have!

For any of you with a '90s era Monaco coach that is wandering and handling poorly, you need to purchase 20 Atro suspension bushings from Rupparts. The problem is that the original bushings are absolute junk.

We have a 1600 mile round trip coming up in early September, and I will report further about the handling characteristics. I know it will be a very good report.

We are planning a long trip into the U.S.A. in October. Before that trip, I am going to install the single cross brace according to Van's design. I will report on those results also.

Van, I want to thank you very much for your help in this. It is because of your interest in solving this that we are now the proud owners of an excellent handling motor coach. We are now very much looking forward to using our coach to enjoy this great land of ours!

[moisheh]

I have been following this thread not because we have a handling problem but rather because I was so impressed with the research that Jim,Van and and others have put into solving the problem. Maybe I missed something but how did you come across Rupparts and how does a snowmobile parts dealer get to selling bushings for a Monaco? Is he a Monaco owner? I remember Rupp from the early days of snowmobiling. What an excellent thread!

[crah]

Thanks for the uodate guys. Ive been following all this as well. It seems the pre 2000 chassis all benefit from the Atro bushings. Quite a while back we discovered that monaco changed the bushing types somewhere around 2000. As my follow up to my original post, I changed my rear panhard bushings to the atro bushings and it made no difference. I elected to not change my front bushings because I had the newer style monaco bushings that do not over flex. What is odd about all of this is that not all roadmaster chassis wander. Van you mentioned your 2000 dynasty is wander free. I wonder why that is? I would be interested in being a guinee pig considering I havent found my cure yet. One thing that seems undeniable is that the atro bushings are the biggest improvement on the pre 2000 chassis.

[Papa_Jim]

I am very thankful for the IRV2 forums. Without it we never would have had any of this discussion and found a solution to this frustrating wandering issue on the '90s era Monaco coaches. This has indeed been a very interesting thread. Thanks to Craig for getting it going. Thanks to everyone for their input. It has been great for me, my coach now does not wander, or at the very least, has become very easy to control.

I am of the firm belief that the Roadmaster chassis, at least in the '90s era coaches, has a serious structural design flaw. I am surprised that it has not caused accidents. I was drawn to buying a Monaco coach because I reasoned that an eight outboard air bag suspension was superior to truck style suspensions with their four inner air bags. As far as the outboard position of the air bags providing sway stability, I still believe that to be true. As a result of this thread I became aware about how the suspension is actually designed on the Roadmaster chassis. The axles are bolted to H Frames which are connected to the coach frame at the outside corners of the H Frames with air bags and shock absorbers.

Now for me, this is where is gets really interesting. The rear axle is bolted to the H frame. Then four trailing arms with bushings at each end of each arm are fastened to the back of the H frame and run back behind the H frame and are fastened to the coach frame. It's these four trailing arms that do all the push-pull work of making sure the coach is pulled down the road, but also doing all the work of holding the coach back when braking and going down hills. I suppose that in itself is OK. But these four trailing arms have nothing to do with the directional relationship of the H frame to the coach frame. For directional stability, something had to be designed to make sure that the H frame and the coach frame are in exactly the same plane at all times. For me, this is where Roadmaster dropped the ball. Roadmaster tried to address the directional stability issue by installing one pan head bar going sideways from the H frame to the coach frame. But that one bar cannot control the twisting movement of the H frame underneath the coach.

The front axle is also bolted to its own H frame. Four 'trailing' arms are fastened to the front of that H frame and run forward to be fastened to the front of the coach frame. Then one pan head bar goes sideways from the H frame to the coach frame. So, while the coach is going down the road, the trailing arms are pulling the H frame along. The one pan head bar is guiding the sideways position of the H frame. Nothing is controlling the directional stability of the H frame. So, while the steering wheel is aimed straight ahead, the entire H frame can decide to twist sideways, in effect, the wheels are now trying to turn sideways somewhat. No wonder the steering feels vague for the driver at the steering wheel.

While I am pleased with the results I have obtained by replacing the old inferior suspension bushings with the new Atro bushings, I am dedicated to finding the true solution to the design flaw that is the root of the wandering problem. I believe that Van has the right idea with the addition of a cross brace. I believe that somehow more directional stability control has to be designed into the suspension so that we know that the H frames are locked into a position of stability underneath the coach at all times, under all circumstances. To that end I will be eventually installing at least one cross brace in the attempt to accomplish this. I will be communicating with Van when I build and install that cross brace.

I believe that an ideal suspension would be a traditional truck style suspension (with no H frames) that also employs the outboard air bag design. That would be the absolute best of both worlds. Having said that, we have to work with what we have. We have to solve the inadequate design in the Roadmaster chassis coaches that we have.

Oh yes. I have a theory regarding the Monaco tag axle coaches, one that is unproved. I believe that the tag axle is mounted to the actual coach frame, not to an H frame, therefore it in itself is very stable as far as its relationship to the coach frame. If this is true, then it explains in part why the Monaco tag axle coaches handle so well. This would also reinforce my current opinion that a true truck suspension with outboard air bags would be the ideal.

Craig, you report that replacing the rear bushings provided no improvement. I learned that the design of the new bushings requires that the bolts are tightened enough to squeeze the steel center of the bushings very tightly between the brackets. If the steel center of the bushing can move, that bushing could provide no more control, or even less control than the original bushing that was replaced. Are your bolts tight enough? Just a thought.

[blahargoue]

I'm late to the party on this discussion. But, the Monacoers Yahoo chat group has been discussing this topic for a few years. One member named "Van W" has likely identified your handling issue and has a solution. It deals with the suspension bushing in the rear end of the rig, not the front. Here's an excerpt of one of those discussions:

"Ron,
Why are you interested in replacing the bushings? If it is in hopes of
tightening up your suspension to eliminate or reduce wandering, you are
definitely on the right track. Three suggestions—1) Adjust your steering gear
for minimal looseness. 2) Start with replacing the two rear Panhard rod
bushings. Your wandering originates in the rear, NOT the front. 3) Use the
very stiff ATRO polyurethane bushings available from Ruppparts dot com.—approx
$35 each.


I replaced ALL my bushings with ATRO bushings and also welded
Heim-joint-equipped cross-braces to both front and rear lower trailing arms.
Previous to those modifications, my coach was basically "road wild", seemed to
have the steering wheel connected to the suspension with a Jello coupling,
required constant steering input to keep it in its lane, was absolutely scary
when passed by a tractor-trailer, and would wear you out to drive it for three
hours down an interstate highway. After bushing replacement and the
cross-braces, I drove the beast 650 miles from NC to Seffner, FL for the
Gathering, and could easily have made the twelve hour drive in one day had I
chosen to. It drove straight as an arrow in punishing, gusty crosswinds, and
one out of three tractor trailers surprised me when passing, because I did not
notice them until I saw them in the driver's side window as they passed. I
steered most of the way with two fingers and a thumb of my left hand, while
observing the scenery, tuning the radio and drinking from a cup in the console.


By far, the most difficult part of the job is getting the bolts out. They are
body-bound 7/8 fasteners in holes that were punched (not drilled) in their
brackets and when they have rusted to those brackets, they are extremely
difficult to remove. Add to that the fact that most rear bushings have a thin
metal sleeve on the ID, which has also rusted to the bolt, and you will need a
very strong 3/4 impact wrench and super-duty air hammer to get them out. I also
had to weld up a bolt-pulling device. But the results are well worth the
effort. You will not have cured the basic design flaw in the Roadmaster
chassis, but you will have masked it to the point that you will almost surely be
very happy with the results. If you also add the cross-braces, you will be
DELIRIOUSLY happy. It does not matter how short your coach is. There is a 31'
Dynasty owned by one of our members that handles just as well as mine.


BTW, removing and remounting the wheels, front or rear, is not the job some make
it out to be. Getting the lugs loose can be a butch, but the wheels are
manageable, and are easily aligned and remounted using a large crowbar or pry
bar under the tire. Be sure you have super-duty jack stands."

I hope this info will steer up in the right direction.

Bruce L.

[crah]

Originally Posted by jimkate

Craig, you report that replacing the rear bushings provided no improvement. I learned that the design of the new bushings requires that the bolts are tightened enough to squeeze the steel center of the bushings very tightly between the brackets. If the steel center of the bushing can move, that bushing could provide no more control, or even less control than the original bushing that was replaced. Are your bolts tight enough? Just a thought.

Jim, Van posed the exact same question to me a while back. I dont have an exact answer on how tight it is or know what torque value is required to be considered adequate. What I do know is that I have a cheap harbor freight 1/2 inch impact wrench rated to 850 ft pounds. Im positive its not up to par in torque to an equal quality made tool. However, this is the same impact wrench that removed the front and rear panhard bars as well as my front axle. Even if the output is only half of the stated value, I am thinking 400 ft pounds should be adequate? I may be wrong on that, but im pretty comfortable thinking its tight enough. If anyone has an actual torque requirement, please share.

Finally, the newer monaco style bushings I had were actually stiffer than the atro bushings. Thats why I elected to keep my front panhard bar bushings alone. I had the same feeling when I replaced the rears but I figured I would try it in case I was wrong. For anyone thats not following the entire thread, the pre 2000 era roadmaster chassis had the very poor thick rubber bushings that needs to be replaced with the atro bushing from rupparts.

[Papa_Jim]

Craig,

I don't have a specific torque. I've heard 400 lb. I don't know. Van reminded me to make sure the bolts were tightened properly. I do know that our bolts were tightened with a 3/4" drive air gun, then tightened more with a long pull bar, basically as tight as the man could pull the bar.

[crah]

Jim

Regarding on your question on the outboard mount airbags, im pretty sure the non tag foretravels have 8 outboard airbags. It would be interesting to see a chassis comparison.