Community Forums

DC Cruiser · 11-12-2011, 10:33 AM

Also have your ride height checked or adjusted and then I totally agree with Nodine. Yes Source should have the REK for your coach ready as they used my coach as their test bed for the fit of the sway bars which also has the RR8S frame. Call Jim at Source and he should be able to set you up. Remembering that you are driving a 20T fridge down the road that is never going to be totally immune to cross winds etc the sway bars are such a vast improvement in this area that I can now comfortably drive in the severe cross winds of northern Montana and southern Alberta for 6-8 hrs and not feel like I went 12 rounds with Mohamed Ali. Again as I have said before my coach is now a joy and fun to drive and if you are a traveler and enjoy the driving part of RV'ing and not just a parker then the pleasure of driving an excellent handling and riding Class A Diesel Pusher is well worth the expense and time invested.

CHEERS

crah · 11-12-2011, 10:59 AM

Thank you Bob and DC Cruiser. I'll talk to Source on Monday. I'm sure the cost will be hefty and I'm far from retirement. I'll see if I can buy parts at a time starting with the sway bars.

Papa_Jim · 11-12-2011, 11:12 PM

Well, I have to agree with the opinions expressed by Mike Canter on this one. When we first bought our coach, it wanted to go all over the road, wandering and following every road rut. Two alignments and a lot of dollars later, I finally got at it myself and, as Mike explained, I adjusted the clearance in the steering box myself.

Our coach has handled very well every since.

Dutch Star Don · 11-14-2011, 11:47 AM

crah......I have a 36' Diplomat and is probably very close in handling to yours. Right off the bat, our coaches are both TOO short to handle as well as the larger ones. They are going to overact to any steering imput because of the short wheelbase and front and rear overhang. The wheelbase on ours is about the same as a 32' gasser. I added the Koni FSD's and saw a huge improvement in the jarring ride in the front end and some moderate improvement in handling. I adjusted the ride height that was off by an inch both front and rear and was astonished by how the coach ride improved. In my mine, it doesn't seem possible that an inch adjustment front and rear would change the dynamics so much, but it did.

It was about four years into the ownership of the coach that I had a four wheel alignment by a truck shop. The alignment guy showed me that my front wheels were set at zero degrees tow. He said this was within the specs, but would make the coach wander. He added tow-in to both front wheels and the coach (with two new front tires) tracked like a dream.

When everyone was receiving such great results with the sway bars, I added them to mine. I didn't see the improvement that everyone else did. I later spoke to Source Engineering and they agreed that the improvement in handling, wind and passing trucks would not be as pronounced in a coach as short as ours. Surprisingly, it did improve the ride in the front end. The front sway bar distributed the road bumps between both front wheels and shocks.

I'm always looking for ways to make my coach handle better, but I also realize that when I drive in most conditions, I only use my thumb and index finger to drive with complete control. I know others who are using both hands and are exhausted by the end of the day. This past summer, we drove from Los Angeles to Provo, Utah, towing my truck, without being exhausted (675 miles).

Do all of the inexpensive things you can to the coach to change the handling and then move on to the more expensive additions. Shocks, alignment and ride height are a must. The sway bars are nice, but won't be as dramatic as the others experienced. They're still nice. I can turn the coach so sharp that stuff will come out of the cabinets before the coach will lean.

Finally, play with the tire pressure. I've changed mine up and down several times. I was running as low as 95 psi front and 85 psi rears. I finally settled on 105 psi front and 95 psi rears.

Perry White · 11-14-2011, 12:15 PM

Rub your flat hand across your tire tread. If it is smooth one way and rough the other, you have tow problem. It's not perfect but close. Mike C's got it right. It's kind of hard to over tighten the steering box. Not impossible but not probable.

Mike Canter · 11-14-2011, 12:33 PM

Diplomat Don is 100% correct on sway bars and how they work. Sway bars only apply an equal and opposite force from one end of the bar to the other. They are designed to stop the MH from leaning over while corning. When the MH tries to lean in a curve or corner it will apply the opposite and equal force to bring it upright. That is why they call the SWAY bars or really anti-sway bars. If you are driving straight and level on a road they have ZERO effect. When a truck passes you or the wind hits you it would have to be of enough force to make the MH lean enough to work the sway bar so therefore they are not going to do you much good to stop a MH from wandering or feeling jittery going down the road.

crah · 11-17-2011, 11:34 PM

Don and Mike,

Thanks for the further input on the sway bars. Don, my situation may be even worse than yours. I believe my HR has a wheel base 1 ft. shorter than yours either though overall coach length is the same. I think it was an HR thing back in my vintage compared to the Monacos. The HR's seemed to all have shorter wheel bases. Mine is at 216". I'm a little hesitant on the sway bars for the amount of money. My biggest problem now is the passing cars and semis. I can even feel cars when they pass me. Not dangerous, but very bothersome. On the other hand the semis will give me a pretty good push. Nothing I can't manage of course, but it would be nice to not have that as an issue. The wind can get a little harry at times. Has anyone tried the motion control valves? Seems that I see some reviews that they help in the wind. I don't see many posters that have actually tried them though, and the select very few say they work.

nodine · 11-18-2011, 01:53 AM

Quote:

Originally Posted by crah

Don and Mike,

Thanks for the further input on the sway bars. Don, my situation may be even worse than yours. I believe my HR has a wheel base 1 ft. shorter than yours either though overall coach length is the same. I think it was an HR thing back in my vintage compared to the Monacos. The HR's seemed to all have shorter wheel bases. Mine is at 216". I'm a little hesitant on the sway bars for the amount of money. My biggest problem now is the passing cars and semis. I can even feel cars when they pass me. Not dangerous, but very bothersome. On the other hand the semis will give me a pretty good push. Nothing I can't manage of course, but it would be nice to not have that as an issue. The wind can get a little harry at times. Has anyone tried the motion control valves? Seems that I see some reviews that they help in the wind. I don't see many posters that have actually tried them though, and the select very few say they work.

Just bare in mind that the problems you are wishing to correct are the exact same ones that I wanted to correct. The sway bars did it for me. Now the 18 wheelers will sometimes sneak up on me. Before the sway bars I could feel them coming before they overtook me. No disrespect to Don and Mike, but there is more going on here than just compensating for sway. It all has to do with how the rear of the motorhome causes something like a bump steer at the front of the motorhome. You have to move the steering to compensate for a force vector at the rear that is not at the front. Sway is usually a side to side force across the length that is caused by the inertia and top heaviness of the vehicle going around a turn. If the sway does affect the steering you usually don't notice it because you are in a turn and mvoing the steering wheel anyway. If you are traveling straight down the road and you have a force acting on one end of the vehicle that is not present at the other end then you have to move the steering to compensate. Vehicles with a low center of gravity have almost no sway. In my mind the sway bars on an RR8R chassis act on the same principle as a tag axle. The tag is out behind the drive axle and helps to keep the rear of the motorhome from moving the front of the motorhome. It is true that a shorter wheel base should be less affected by the motion of the rear end in respect to the front, but you seem to have the problem as I did.

Off my soap box now. I will say no more on the subject.

Bob

Mike Canter · 11-18-2011, 05:53 AM

Let me explain it is a little different way to include Bobs observation and results when he installed his bars. Sway bars attach to the frame and to the axle. In order for them to work the one side of the body/frame or the axle has to move so equal and opposite force is applied to the other side. If you are going in a straight line down the highway then there are no forces applied. The bar is then considered to be in a neutral position. If the MH body leans then the equal and opposite force is applied that will attempt to push the MH body (not the sterring) in the opposite direction to straighten it up. So now just driving down the road and wandering back and forth does not cause the MH body to roll so it remains in the neutral position so it will not correct that. Now if a gust of wind from one source or another hits the side of the MH body and tries to push the body over then these equal and opposite forces are applied and will keep the body upright. This would help in heavy crosswinds or winds/suction created by passing 18 wheelers. Wondering or not tracking does not apply any side force to the body so the bars are not working and remain neutral. Again this is why they are called "Sway Bars" or "Anti Roll Bars". One just needs to understand what the problem is with your MH and what you are trying to correct. If it is wondering or not tracking with no wind or passing trucks them bars are going to do nothing.

wa8yxm · 11-18-2011, 02:45 PM

I too have felt the steering on my 2005 Damon Intruder was a bit.. er.. sloppy.

I made two modifications: I added a trac bar. Though I have the Davis True-Track on the FRONT axle.. most folks recommend doing the rear first.. When I get around to the rear in 2 or 3 years that will be an Ultra Trac (Just saving the Ultra folks the trouble of .. Oh heck guys go ahead and plug your product) As long as you are not judging by price tag it appears to be every bit as good as the Davis model, Only less costly. (I have met folks who judge by the tag.. (When I sold paint) so I told them where to get the same color for more money.... I might add, same paint exactly save for the price tag.. Heck, I worked for the paint company)

The other addition was the Blue-Ox Tru-center steering stablizer... There are competitors,, This is the one that best appealed to me however due to the ability to re-adjust from the driver's seat (very handy).

Result... I did not notice too much difference departing the installs (Different times) but when the Tru-Center had to return to Pender, sans the coach, for some replacement therapy.... BIG difference... You see I'd gotten used to the "new and improved" handling.

deSanford · 11-18-2011, 09:19 PM

I enjoy a good handling motorhome and adding all the above improvements is just part of the hobby. Just ordered a new fan from Scott at Source. That should lower the rear noise, and improve the power a little. Hope to have it installed before we go to Quartzsite.

Vanwill · 11-28-2011, 09:01 PM

I always look forward to seeing posts from Mike Canter. I think we have similar backgrounds and tend to attack problems the same way. I've learned a lot from him.

There is no reason to fear adjusting your steering gear box. I'm 63. I've been doing it on almost every car I've owned beginning at age 13. And Mike is correct that steering boxes have not changed since the 50's. Your steering wheel movement rotates a ball screw, which in my experience will outlast just about any vehicle it is attached to. The ball nut moved by that ball screw (with balls under preload) has a rack gear on its back, and that rack rotates a gear sector which is attached to the Pittman arm. The gear sector has a tapered pitch diameter, so that if you move it to the smaller pitch diameter, clearance ("play") increases...and vice-versa. The adjustment screw Mike refers to is what adjusts the sector's clearance to the rack gear. Since the two gears are essentially an involute spur gear engaging a rack gear you would have to tighten the crap out of that screw to cause any galling. It’s not as if it’s the worm gear setup on my first car, a Model A Ford. And though all technical texts will tell you to remove the steering gear from the vehicle to set the position of the adjustment screw, I've done that on ONE car. The other 28 were adjusted in situ. The point is, like Mike is saying, it ain't rocket science. In my experience, almost every vehicle can benefit from a small adjustment. And if you do as Mike said and mark your starting position, you have nothing to lose. I would say that adjusting your steering box is the place to start, IF, as Mike said, you can see that the Pittman arm DOES NOT MOVE when you rotate the steering wheel through its “play” zone. It costs nothing, and will likely improve your situation if indeed it does not cure it.

HOWEVER, Mike, perhaps you can think of an explanation for this case. I had a 95 Fleetwood Jamboree Class C as my first MH. I drove it from FL to NC and it scared the living crap out of me. It felt like it was a saucer sliding down a greased highway. It wandered all over and felt like it had lots of play in the steering gear. When ANYTHING passed me (I passed NO ONE) it felt like I would lose control. I pulled over at a rest stop and adjusted the steering gear. It was a near miraculous improvement. The fact that it STILL felt a little “loose on the road” was something I knew I’d attack when I got home…or that it was something I would just have to get “used to” since I had not driven something any bigger than a dump truck for many years. To make this long story as short as possible, I did everything that my lifelong experience led me to do. Nothing really improved it further…UNTIL I decided to replace the anti-roll bar bushings. One of them was all but totally gone. BINGO! The coach could now be steered with one finger and a thumb. And I’m talking about just driving down a straight interstate. I repaired the sway bar last, because I knew it SHOULD have no influence on straight-line steering. But it did, and in a major way I have never seen any other time in my life. I cannot explain it from a mechanical engineering standpoint.

My “new to me” 93 Dynasty seems to me to handle quite well, in spite of the fact that it weighs almost 10,000 pounds more than my previous one. I think there is still room for improvement, so you can bet my first step will be to adjust the steering gear.

So, even though I can find no reason that a sway bar would improve straight-line steering, I know for a fact that it did it at least one time. And at a price that I feel is reasonable, I’ll add it to my 93 Dynasty.

deSanford · 11-29-2011, 08:02 AM

Nice to know Vanwill that the sway bar can help on straight line steering. I know from driving experience it helps in winds and going around curves. Able to take the freeway on ramps at the rated speed or maybe a little faster with hardly any lean of the BIG box. Always puts a smile on my face to a point it almost hurts.

ottffss · 11-29-2011, 10:24 AM

Quote:

Originally Posted by Vanwill

So, even though I can find no reason that a sway bar would improve straight-line steering, I know for a fact that it did it at least one time. And at a price that I feel is reasonable, I’ll add it to my 93 Dynasty.

The reason you saw straight line improvement is that IF the box is rocking it is ever so slightly but sufficiently enough changing steering geometry (by slightly lifting one side of the frame and slightly pressing the other side - do the rest of the math on the geometry) and even changing side-for-side tire loading causing straight line tracking to be affected. Vehicles are a system - many things affect others in sometimes not obvious ways.