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

[DappemAV8]

Hello Everyone!
I've enjoyed reading all of the post on here about the ride and handling of the Roasmaster chassis. I also enjoyed the two presentations given by Van and Craig at the MS in Goshen. Tons of good information!

I've had my coach for just over two years. I've never really thought that it had any of the issues most people complain about with the poor handling, until now. I do find it a bit squirrely in the wind and when trucks pass on the interstate. I have a TRW steering gear that is tight, so I can assume that helps. The one thing that I have started to notice is between ~58-62mph I have a slight vibration in the front. It seems like the type of vibration you'd experience when a tire is out of balance, but I have Centermatic balancers on the front so I have almost eliminated that as a cause. The vibration is not in the steering wheel but more in the chassis and its not terrible. The coach as 62000 miles on it and I'm pretty sure that the shocks are original.

With all the smart people on here I wanted to run this issue past everyone. Would new shocks help with the vibration? Front Watts Link and rear cross bars? New bushings?

Thanks in advance-
Darren
2004 HR Imperial

(Posted on MonacoForums as well)

[Steve Ownby]

Originally Posted by DappemAV8

Hello Everyone!
I've enjoyed reading all of the post on here about the ride and handling of the Roasmaster chassis. I also enjoyed the two presentations given by Van and Craig at the MS in Goshen. Tons of good information!

I've had my coach for just over two years. I've never really thought that it had any of the issues most people complain about with the poor handling, until now. I do find it a bit squirrely in the wind and when trucks pass on the interstate. I have a TRW steering gear that is tight, so I can assume that helps. The one thing that I have started to notice is between ~58-62mph I have a slight vibration in the front. It seems like the type of vibration you'd experience when a tire is out of balance, but I have Centermatic balancers on the front so I have almost eliminated that as a cause. The vibration is not in the steering wheel but more in the chassis and its not terrible. The coach as 62000 miles on it and I'm pretty sure that the shocks are original.

With all the smart people on here I wanted to run this issue past everyone. Would new shocks help with the vibration? Front Watts Link and rear cross bars? New bushings?

Thanks in advance-
Darren
2004 HR Imperial

(Posted on MonacoForums as well)

I would freshen up the grease in the drive shaft slip joint and the universals first. It's cheap, quick and might fix the problem.

[nodine]

Originally Posted by DappemAV8

Hello Everyone!
I've enjoyed reading all of the post on here about the ride and handling of the Roasmaster chassis. I also enjoyed the two presentations given by Van and Craig at the MS in Goshen. Tons of good information!

I've had my coach for just over two years. I've never really thought that it had any of the issues most people complain about with the poor handling, until now. I do find it a bit squirrely in the wind and when trucks pass on the interstate. I have a TRW steering gear that is tight, so I can assume that helps. The one thing that I have started to notice is between ~58-62mph I have a slight vibration in the front. It seems like the type of vibration you'd experience when a tire is out of balance, but I have Centermatic balancers on the front so I have almost eliminated that as a cause. The vibration is not in the steering wheel but more in the chassis and its not terrible. The coach as 62000 miles on it and I'm pretty sure that the shocks are original.

With all the smart people on here I wanted to run this issue past everyone. Would new shocks help with the vibration? Front Watts Link and rear cross bars? New bushings?

Thanks in advance-
Darren
2004 HR Imperial

(Posted on MonacoForums as well)

From your description may I suggest that you take your hand and check the tightness of all your side panels. Monaco used straps made of aluminum to secure the bottom of side panels to the frame and it is quite common for the screws to loosen or break. While traveling at highway speed the wind can cause a loose panel to vibrate.

Bob

[DappemAV8]

Originally Posted by Steve Ownby

I would freshen up the grease in the drive shaft slip joint and the universals first. It's cheap, quick and might fix the problem.

I've read that the drive shaft my cause some vibration and it feels like it may be coming from that location and transmitting through the frame. I'll take a look at that. Thank you!

[DappemAV8]

Originally Posted by nodine

From your description may I suggest that you take your hand and check the tightness of all your side panels. Monaco used straps made of aluminum to secure the bottom of side panels to the frame and it is quite common for the screws to loosen or break. While traveling at highway speed the wind can cause a loose panel to vibrate.



Bob

I've also thought that it might be some aerodynamic buffeting. It seems to change with different cross winds. I'll take a look at that as well. Thanks guys!

[Petebur]

Hello DappemAV8,

I just had a similar experience this past week with vibration in the front that felt like it was coming through the chassis, and not so much through the steering wheel. I thought it was a balance problem with one of the front wheels.
I stopped at a Love’s truck center and had the front tires checked. When the mechanic ran the left front wheel on the balancer it called for 2 pounds of weight. Over a pound more than he was allowed to use.
He then spun the wheel by hand and you could see that the tire had a large flat spot worn in the tread.
If your centramatic can not balance the tire, then I would suspect you may have a bad tire. I would have it checked at a truck tire facility.
Just my opinion from my recent experience.
Good luck in finding your problem.

[10Boomer]

Originally Posted by mhughes

Hi Folks,



Working on a chart to gauge variation in dimensions on 2001-2006 Diplomat, Knight, Ambassador, and Endeavor front H-Frames.



I was wondering if those who have access can measure and post the distance from the jack mount (chassis frame) to the rear of the H-Frame as well as the distance from the front face of the jack to the rear of the H-Frame.



Also be helpful if you can specify whether or not you have 4 external springs on the front jack.



And, thanks in advance to those who can provide this.

Mike see you have Endeavor listed, need Camelot info? This fall I will be ready for x braces! Take care Mike!

[10Boomer]

Originally Posted by mhughes

Thanks boomer but I'm primarily interested in the coaches listed (I may have incorrectly listed the Endeavor).



I've installed front watts on more than 30 of these coaches and find the measurements all over the place (snowflakes). A chart with the year, model and measurements would a great thing to have.

Yes, it may or may not show a pattern, or some consistency with each model, maybe!

[nodine]

Originally Posted by mhughes

Hi Folks,

Working on a chart to gauge variation in dimensions on 2001-2006 Diplomat, Knight, Ambassador, and Endeavor front H-Frames.

I was wondering if those who have access can measure and post the distance from the jack mount (chassis frame) to the rear of the H-Frame as well as the distance from the front face of the jack to the rear of the H-Frame.

Also be helpful if you can specify whether or not you have 4 external springs on the front jack.

And, thanks in advance to those who can provide this.

Mike,

Just saw your post and will make a note to take measurements as soon as possible

Bob

[nodine]

On the majority of Monaco models the front and rear axles of the Roadmaster chassis are attached to a structure referred to as the H-frame. This moniker came about because it somewhat resembles the shape of the letter H. The H-frame is attached to the main frame by two upper and two lower trailing arms and a single Panhard bar. Air bags at each corner of the front and rear H-frames support the weight of the motorhome. This describes the RR8 chassis. The RR10 chassis is similar but has a tag axle with two additional air bags behind the rear H-frame. All of the H-frame attachments to the main chassis allow motion. The trailing arms and Panhard bar are attached at each end with bushings. The intent of the designers of the Roadmaster chassis was that the H-frame would only move in the vertical direction and the combination of the trailing arms and Panhard bar would stabilize motion in the lateral and rotational directions. They do accomplish this but the long length of the trailing arms, the flexible nature of the bushings, the single Panhard bar, and the inherent flexibility of the air bags allow movement in other directions. The subject of this post is that even a small amount of movement in any direction other than vertical will affect the handling of the coach.

For those of you that don’t know me, I have been involved with the application of the Watts link on Monaco coaches from the beginning. Van Williams (Vanwill) conceived that an inverted Watts link could be adapted to the front H-frame of a Monaco Roadmaster chassis to mitigate lateral and rotational motion of the axle. Each H-frame only has one Panhard bar resulting in rotational motion around that tie point when outside forces such as wind and passing trucks push on the body of the coach. Adding a second Panhard bar is next to impossible due to interference from items like ping tanks, etc. Van realized that a Watts link attached to the section of H-frame farthest from the PanHard bar would stabilize the H-frame. Being the busy man that he is he did not move to implement his idea. I was intrigued with the concept and ask him to build one for our 2006 Diplomat. He instructed me to take measurements and send them to him but was reluctant to fabricate the Watts link without the coach at his place. Having some experience with mechanical drawing I drew up plans for a front Watts link for our coach and sent them to Van. That was enough to encourage him to fabricate the Watts link and ship it to me. After installing it on the coach we took a trip out west and grave frequent reports back to this thread on the handling improvement. Even before we returned home from that trip Van had clients at his place anxious for a Watts link.

Van and I have been suspicious that a non-vertical movement in the H-frame of less than 1/8 of an inch can result in a noticeable change in handling. In post #1615 of this thread I postulated mathematically that a 0.1 degree change in the steer axle at 60 MPH would change the intended direction of travel by 1.84 inches in one second. Van and I have had experiences to back up our suspicions. Van installed a front Watts link on a couple’s coach but was distracted during the process and forgot to completely tighten the clamps attached to the H-frame. After leaving his place the couple called back and indicated there seemed to be negligible improvement in the handling. Van realized he had not completed tightening the clamps and asked them to stop at the first convenient location and tighten them. They later reported back a significant improvement in handling after the clamps were sufficiently tightened.

Our coach has about every Roadmaster chassis mod including front and rear Watts links. We would often stop at a rest stop and be surprised at how hard the wind was blowing. Before the Watts links you would definitely notice the wind while driving because corrections with the steering wheel would be necessary to compensate for the wind gusts. On our way back from Alaska last year we began to notice degradation in the handling of our coach. Like old age, the magnitude of the severity was masked by the slow decline. We again became aware of passing trucks and the necessity to oversteer in curves. It is easy to make these statements now after solving the problem but at the time we were puzzling as to what could have happened to the coach. We were at the Monaco Gathering at Lazydays Tampa in February along with Van and Craig French (CrazyKnight). Craig is another guy who’s tireless effort on swapping out Sheppard steering sectors for TRW ones has been a tremendous benefit to the Monaco community. He has also installed a number of Watts links on fellow Monaco coaches in the spirit of paying it forward.

One of the free services that Craig performs for his fellow Monacoers is to check and adjust their TRW steering sectors. Thinking that maybe our steering sector had worn on the long trip to Alaska and back, I ask Craig to check mine. While waiting on Craig to get to our coach I went under to check things out. It occurred to me to reach up and check the bell crank pivot. I noticed it was loose and could be moved slightly back and forth. Van was under the coach and knew immediately that the weld on the back of the pivot bolt had broken. Craig still checked the TRW but found it tight. After finding the loose bell crank we were sure that was our problem. Craig had picked up several versions of Mike Hughes Watts link kits in Quartzite for display at the Gathering. We already had one of Mike’s rear Watts links on the coach and knew how well they were built. Mike said Craig could sell us one of the front Watts link kits so we purchased it. We have been busy building an RV garage and only installed the new Watts link kit two weeks ago in preparation for a trip to Lynchburg, VA.

We live 12 miles from I-40 and must travel back country roads to reach the interstate. As we made our way to the Interstate we noticed that it was no longer necessary to oversteer in the curves. Once we reached I-81 we headed north to Southwest Virginia. The winds in that part of Virginia seem to blow all the time and can be significant. At times we thought we were back in North Dakota. The new Watts link had returned the coach to handling like a dream and it was necessary to look at the trees and flagpoles to know how active the wind was. No longer did we feel the passing 18 wheelers as they went by us and driving in the wake of a truck was effortless. The coach again handled like it did before the Alaska trip. I placed the old bell crank assembly with the broken weld on my work bench and checked the endplay of the pivot bolt with a dial micrometer. See for yourself in the Youtube link below the total endplay was about 0.025 of an inch. It is mind blowing that such a small movement could have that much impact on handling.

https://www.youtube.com/watch?v=m0IEbHypRvA

Bob

[rmcb]

I had the same type failure on my home made pivot. I attributed it to my crappy welding but after talking with Mike Hughes at Q this year, I have thought that it may be a little much to expect that pivot bolt to withstand all the possible forces that could act on it with it only secured on one end. I really like the way Mike's design supports the pivot bolt on both ends. I am in the process of remaking mine to do the same thing. I'll post pictures when done.

Roy

[nodine]

Originally Posted by rmcb

I had the same type failure on my home made pivot. I attributed it to my crappy welding but after talking with Mike Hughes at Q this year, I have thought that it may be a little much to expect that pivot bolt to withstand all the possible forces that could act on it with it only secured on one end. I really like the way Mike's design supports the pivot bolt on both ends. I am in the process of remaking mine to do the same thing. I'll post pictures when done.

Roy

Hi Roy,

The new Watts link kit we have on the front has the support on the front of the pivot bolt. When I first saw the support I wondered if the bell crank would have sufficient clearance but had confidence in Mike. After installing the kit we ran the ride height all the down just to make sure the bell crank did not contact the front support. All was good.

Bob

[DappemAV8]

Originally Posted by nodine

On the majority of Monaco models the front and rear axles of the Roadmaster chassis are attached to a structure referred to as the H-frame. This moniker came about because it somewhat resembles the shape of the letter H. The H-frame is attached to the main frame by two upper and two lower trailing arms and a single Panhard bar. Air bags at each corner of the front and rear H-frames support the weight of the motorhome. This describes the RR8 chassis. The RR10 chassis is similar but has a tag axle with two additional air bags behind the rear H-frame. All of the H-frame attachments to the main chassis allow motion. The trailing arms and Panhard bar are attached at each end with bushings. The intent of the designers of the Roadmaster chassis was that the H-frame would only move in the vertical direction and the combination of the trailing arms and Panhard bar would stabilize motion in the lateral and rotational directions. They do accomplish this but the long length of the trailing arms, the flexible nature of the bushings, the single Panhard bar, and the inherent flexibility of the air bags allow movement in other directions. The subject of this post is that even a small amount of movement in any direction other than vertical will affect the handling of the coach.

For those of you that don’t know me, I have been involved with the application of the Watts link on Monaco coaches from the beginning. Van Williams (Vanwill) conceived that an inverted Watts link could be adapted to the front H-frame of a Monaco Roadmaster chassis to mitigate lateral and rotational motion of the axle. Each H-frame only has one Panhard bar resulting in rotational motion around that tie point when outside forces such as wind and passing trucks push on the body of the coach. Adding a second Panhard bar is next to impossible due to interference from items like ping tanks, etc. Van realized that a Watts link attached to the section of H-frame farthest from the PanHard bar would stabilize the H-frame. Being the busy man that he is he did not move to implement his idea. I was intrigued with the concept and ask him to build one for our 2006 Diplomat. He instructed me to take measurements and send them to him but was reluctant to fabricate the Watts link without the coach at his place. Having some experience with mechanical drawing I drew up plans for a front Watts link for our coach and sent them to Van. That was enough to encourage him to fabricate the Watts link and ship it to me. After installing it on the coach we took a trip out west and grave frequent reports back to this thread on the handling improvement. Even before we returned home from that trip Van had clients at his place anxious for a Watts link.

Van and I have been suspicious that a non-vertical movement in the H-frame of less than 1/8 of an inch can result in a noticeable change in handling. In post #1615 of this thread I postulated mathematically that a 0.1 degree change in the steer axle at 60 MPH would change the intended direction of travel by 1.84 inches in one second. Van and I have had experiences to back up our suspicions. Van installed a front Watts link on a couple’s coach but was distracted during the process and forgot to completely tighten the clamps attached to the H-frame. After leaving his place the couple called back and indicated there seemed to be negligible improvement in the handling. Van realized he had not completed tightening the clamps and asked them to stop at the first convenient location and tighten them. They later reported back a significant improvement in handling after the clamps were sufficiently tightened.

Our coach has about every Roadmaster chassis mod including front and rear Watts links. We would often stop at a rest stop and be surprised at how hard the wind was blowing. Before the Watts links you would definitely notice the wind while driving because corrections with the steering wheel would be necessary to compensate for the wind gusts. On our way back from Alaska last year we began to notice degradation in the handling of our coach. Like old age, the magnitude of the severity was masked by the slow decline. We again became aware of passing trucks and the necessity to oversteer in curves. It is easy to make these statements now after solving the problem but at the time we were puzzling as to what could have happened to the coach. We were at the Monaco Gathering at Lazydays Tampa in February along with Van and Craig French (CrazyKnight). Craig is another guy who’s tireless effort on swapping out Sheppard steering sectors for TRW ones has been a tremendous benefit to the Monaco community. He has also installed a number of Watts links on fellow Monaco coaches in the spirit of paying it forward.

One of the free services that Craig performs for his fellow Monacoers is to check and adjust their TRW steering sectors. Thinking that maybe our steering sector had worn on the long trip to Alaska and back, I ask Craig to check mine. While waiting on Craig to get to our coach I went under to check things out. It occurred to me to reach up and check the bell crank pivot. I noticed it was loose and could be moved slightly back and forth. Van was under the coach and knew immediately that the weld on the back of the pivot bolt had broken. Craig still checked the TRW but found it tight. After finding the loose bell crank we were sure that was our problem. Craig had picked up several versions of Mike Hughes Watts link kits in Quartzite for display at the Gathering. We already had one of Mike’s rear Watts links on the coach and knew how well they were built. Mike said Craig could sell us one of the front Watts link kits so we purchased it. We have been busy building an RV garage and only installed the new Watts link kit two weeks ago in preparation for a trip to Lynchburg, VA.

We live 12 miles from I-40 and must travel back country roads to reach the interstate. As we made our way to the Interstate we noticed that it was no longer necessary to oversteer in the curves. Once we reached I-81 we headed north to Southwest Virginia. The winds in that part of Virginia seem to blow all the time and can be significant. At times we thought we were back in North Dakota. The new Watts link had returned the coach to handling like a dream and it was necessary to look at the trees and flagpoles to know how active the wind was. No longer did we feel the passing 18 wheelers as they went by us and driving in the wake of a truck was effortless. The coach again handled like it did before the Alaska trip. I placed the old bell crank assembly with the broken weld on my work bench and checked the endplay of the pivot bolt with a dial micrometer. See for yourself in the Youtube link below the total endplay was about 0.025 of an inch. It is mind blowing that such a small movement could have that much impact on handling.

Bob

How critical is it to mount the Watts Link furthest from the Panhard Bar?

On my 2004 Imperial, the Panhard bar is on the rear portion of the H frame. There would be approximately 12-18 inches between the Watts Link (mounted on the center jack bracket) and the Panhard bar. Will I see less improvement in handling than other people?

Thanks-
Darren

[DappemAV8]

Originally Posted by mhughes

Darren,

After more than a 100 front watts kits installed with virtually all about 18" or so away from the panhard bar I can say that you won't see a difference.

In theory it would be ideal to hold each end of the h-frame assembly in center line of the coach. In reality though, holding it in the center and rear of the h-frame does the same job. Just puts more pressure on the watts bell crank pivot. Any play in this pivot will cancel out the improvement the watts provides more so than if the devices are on opposite ends. This is demonstrated by Bobs comment and video.

Mike-
I've really been thinking about doing this for my coach and I want to do it myself. I was concerned that I'd have to mount the Watts Link on the front of the H frame which would require welding near the generator slide out..I wanted to avoid that so It's good news that 18" will be sufficient. Looks like the only modification I will need to make is trimming the gussets. What have you used in the past to do this? Will a cutting wheel do the trick?

Thanks-
Darren