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

[walt2137]

Im with you Jim!

[nodine]

Originally Posted by walt2137

Im with you Jim!

When it comes to handling and what to do to improve it, Van is the man. Not only is he educated with a degree in mechanical engineering from N.C. State, he has worked on cars all his life and owns a machine shop.

Bob

[wilco1]

OK. I admit it...I skipped here from page 14 when my eyes glazed over on the discussion regarding H-frames and Panhard rods etc.. Forgive me if this was already covered in the ensuing 30 or 40 pages, but it's past my bed time.

Based on my reading over the years and my experience with the coaches I have owned, this is my humble opinion:

1. There is an inherent problem with shorter diesel pushers due to weight distribution. Most of the weight is on the back, which lightens the front and can lead to directional instability.

2. This is complicated by inadequate wheelbase that places the heavy engine even further back, increases the "leverage" and further complicates the weight distribution issue. This also contributes to the weather-vaning effect in a crosswind/passing trucks situation.

3. The reason that tag-axle coaches seem to have few complaints in this regard is that they are generally on longer coaches and the tag effectively lengthens the wheelbase....addressing both point 1 and point 2.

4. Sadly, assuming all the other factors are correct (alignment/tires/ride height/wear and tear/ etc. are correct) there is likely nothing you can do to truly resolve this issue.

5. If the guys at Source Engineering can't solve your problem, likely nobody can, since they were a large part of the Monaco/Roadmaster chassis staff when your coach was built.

Sorry if this has already been covered and if a solution was found somewhere in the posts I didn't read, I stand corrected.

[Papa_Jim]

Originally Posted by wilco1

OK. I admit it...I skipped here from page 14 when my eyes glazed over on the discussion regarding H-frames and Panhard rods etc.. Forgive me if this was already covered in the ensuing 30 or 40 pages, but it's past my bed time.

Based on my reading over the years and my experience with the coaches I have owned, this is my humble opinion:

1. There is an inherent problem with shorter diesel pushers due to weight distribution. Most of the weight is on the back, which lightens the front and can lead to directional instability.

2. This is complicated by inadequate wheelbase that places the heavy engine even further back, increases the "leverage" and further complicates the weight distribution issue. This also contributes to the weather-vaning effect in a crosswind/passing trucks situation.

3. The reason that tag-axle coaches seem to have few complaints in this regard is that they are generally on longer coaches and the tag effectively lengthens the wheelbase....addressing both point 1 and point 2.

4. Sadly, assuming all the other factors are correct (alignment/tires/ride height/wear and tear/ etc. are correct) there is likely nothing you can do to truly resolve this issue.

5. If the guys at Source Engineering can't solve your problem, likely nobody can, since they were a large part of the Monaco/Roadmaster chassis staff when your coach was built.

Sorry if this has already been covered and if a solution was found somewhere in the posts I didn't read, I stand corrected.

I'm sorry.

You stand corrected.

Jim

[nodine]

Originally Posted by wilco1

OK. I admit it...I skipped here from page 14 when my eyes glazed over on the discussion regarding H-frames and Panhard rods etc.. Forgive me if this was already covered in the ensuing 30 or 40 pages, but it's past my bed time.

Based on my reading over the years and my experience with the coaches I have owned, this is my humble opinion:

1. There is an inherent problem with shorter diesel pushers due to weight distribution. Most of the weight is on the back, which lightens the front and can lead to directional instability.

2. This is complicated by inadequate wheelbase that places the heavy engine even further back, increases the "leverage" and further complicates the weight distribution issue. This also contributes to the weather-vaning effect in a crosswind/passing trucks situation.

3. The reason that tag-axle coaches seem to have few complaints in this regard is that they are generally on longer coaches and the tag effectively lengthens the wheelbase....addressing both point 1 and point 2.

4. Sadly, assuming all the other factors are correct (alignment/tires/ride height/wear and tear/ etc. are correct) there is likely nothing you can do to truly resolve this issue.

5. If the guys at Source Engineering can't solve your problem, likely nobody can, since they were a large part of the Monaco/Roadmaster chassis staff when your coach was built.

Sorry if this has already been covered and if a solution was found somewhere in the posts I didn't read, I stand corrected.

You missed the whole point of the thread. This thread is directed at the Roadmaster chassis and was not intended to be a generic application. There are some things that can be done to improve the handling of the non tag Roadmaster chassis. This thread also discusses the poor handling of pre 2000 Monaco coaches due to inferior suspension bushings. The most significant problem with the Roadmaster chassis is the use of only one Panhard bar on the H-frame of the 8 air bag chassis. The Panhard bar is in he center of the H-frame and allows the axle to wiggle or twist from outside forces such as wind.

You are wrong on number 3. The tag improves handling because it prevents the drive axle from acting like a fulcrum when lateral forces push on the rear of the coach.

You are not willing to show any information in your signature so we don't know what type of RV you have. If you have a non tag Roadmaster 8 air bag chassis then you should go back and read some more.

Bob

[moisheh]

Wilco 1 : Your conclusions are based on some quick reading and conclusions you came to before reading this thread. You are wrong in every point! Even your comments on short DP's ( non Monaco) are incorrect. I would suggest you do some more reading and speak to owners of short coaches before posting. If you had read this thread you would have seen that the coaches are not all "short". I have to wonder why you made that post?

[Hooky]

Be nice guys, it was a long thread and technically advanced. He read more than most...

[Vanwill]

All,
Thanks for the vote of confidence. Engineers aren’t usually good at accepting praise. I’m an engineer. Thanks, though. I’m just seeking answers, and still don’t have them all. But this thread has prompted me to discover several of them. I don’t think I would have gotten this far by myself. Thanks to all of you for your suggestions and ideas, and for hanging in there with us as we all home in on the “silver bullet”.

Do bear in mind that this was not MY thread, it was started by Craig, and his coach I still have not stopped from wandering to his satisfaction…but I think we’re close. Also bear in mind that if this thread has demonstrated nothing else, it’s that it is doing what ALL forums hope to do—help one another. Many participants in this thread have contributed a lot. Remember the first guy who asked why couldn’t I come up with something that was “bolt-on”? BOING! Made me feel more than a little inadequate. And within a couple of weeks, we had bolt-on stuff.

Above all else, let’s not let this thread sink into the kind of petty arguing that has rendered so many of them worthless. Those who have followed this thread from the beginning may remember the guy VD…whatever (can’t remember his name), who told us all that he was entitled to be condescending because his intellect, understanding, and experience trumped all ours and he became weary of correcting us. If you recall, he left in a huff. But he also left without contributing anything of value. What progress we have made, we made working together to help one another.

Wilco1 seems to be a non-technical person with some deep-seated technical opinions…a couple of which we know to be totally wrong. But if he chooses to join in the spirit of the thread, he might actually contribute the “next big thing”. I hope so. Wilco1, sometime when you are more alert, might I suggest that you read and try to comprehend the large parts of the thread you skipped over. We have been a long time arriving at where we are, and our path is chronicled in those pages. Should you choose to try the “tail wag” test, you will virtually instantly understand the REAL problem with our Roadmaster chassis and see where some of your assumptions are incorrect. Some of those assumptions are the very ones that the folks on this thread have disproved. Chief among them is what all the old heads will tell you, “Short coaches cannot handle well and will always wander.” To date, the two very best handling coaches I have ever known were a 93 Dynasty 36 that I owned, and a 1991 Dynasty 31 (yes, 31’—I didn’t know they made one that short until I met Chuck). Both these coaches were “road wild” when they were first purchased, and were transformed by the methods outlined in this thread.

Wilco 1, as for your thoughts about the prowess of Source Engineering, I share your respect for their products. Their excellent anti-sway bars could easily be modified to contribute to straight-line stability, not just anti-roll improvement. However, I think you would agree that the engineering expertise of the Chrysler Corporation dwarfs that of Source Engineering. And Chrysler (NOT Monaco) designed the Roadmaster chassis, intending to enter the commuter bus market. When Chrysler chose not to pursue that market, Monaco bought the design, even though Chrysler had never even built a prototype. Had Chrysler built a prototype, they would have discovered the glaring design fault in the chassis and easily corrected it. Over twenty years later, Monaco still did not know what the problem was, and neither did Source Engineering...nor do they now. Should the members of this thread ever, collectively, come up with the definitive, 100% dependable, repeatable solution, I would be happy to see Source Engineering market it. I have no interest in making money from this project, even though I am especially well equipped and positioned to do so.

So, Wilco1, if you have something positive to contribute, you are welcome here. If you just want to argue, even if it is just to argue your list of five points…sorry, I don’t do that. And if you try, you will find that I, and probably most who have contributed here, can ignore you with great ease and aplomb. I hope you choose to join us.

So, guys, I know some of you are offended by Wilco1’s tone, but as Hooky said, give him the benefit of the doubt. He might become a valuable contributor. And thanks to all of you for helping me unravel this mystery that caught my engineering attention. Without so many of you, I would still be “theorizing” about the problem.

Van W 2000 Dynasty 36 pulling one Harley
Eastern NC

[Vanwill]

I remember talking to one of you who had fabrication capability and was thinking of replacing his Sheppard steering box with a TRW adjustable type. I don't remember which of you that was, so would you please identify yourself and tell me if you've made any progress on that idea.

Someone contacted me asking if I knew of anyone who had made this swap.

Thanks!

Van W 2000 Dynasty 36 at Myrtle Beach for Bike Week
Eastern NC

[deSanford]

Just to be clear Source Engineering did NOT design the "Roadmaster" Anti-Sway bars. IPD did and sold the design to Roadmaster who manufacturers them, and sells them through Source Engineering. That said I have used both the IPD original chrome bars and currently have the latest made by Roadmaster. Just got back from a cruise and I am looking forward to installing Van's "bars" on the rear of our "short" mh. deSanford

[Happycarz]

Van,

You are the man! What a wonderful improvement to my coach.

I am now driving in my lane with complete control. Make a minor correction and the steering responds.

I did not think that the cross braces would add much control over what I had with the Koni FSD shocks and Roadmaster sway bars. I was mistaken, as it tightened it up even further. This has been the biggest bang for the buck so far.

I was a little apprehensive when I realized they were over square, during installation. (A lot wider between the trailing arms than the length of the arms.) But these 43" cross braces work like a charm.

This was only a 40 mile test run with toad, but I am pretty sensitive when it comes to NHV and other drivability idiosyncrasies.

So, now you need to make a matching set for my buddy's 40' 08 Scepter. He ordered his coach a couple of weeks before me and our coaches are basically twins. We changed his shocks after I saw an improvement in mine. Then two years ago after I put the Roadmaster sway bars on mine and told him the improvement, I got elected to install sway bars on his.

While talking to him the other day, I let him know my thoughts on the braces. Well, I got elected again. But really not a big deal to me.

The both of us are traveling to Colorado in two weeks, doing a lot of two-laning, so it will be the ultimate test. I'm ready!

[nodine]

Originally Posted by Happycarz

Van,

You are the man! What a wonderful improvement to my coach.

I am now driving in my lane with complete control. Make a minor correction and the steering responds.

I did not think that the cross braces would add much control over what I had with the Koni FSD shocks and Roadmaster sway bars. I was mistaken, as it tightened it up even further. This has been the biggest bang for the buck so far.

I was a little apprehensive when I realized they were over square, during installation. (A lot wider between the trailing arms than the length of the arms.) But these 43" cross braces work like a charm.

This was only a 40 mile test run with toad, but I am pretty sensitive when it comes to NHV and other drivability idiosyncrasies.

So, now you need to make a matching set for my buddy's 40' 08 Scepter. He ordered his coach a couple of weeks before me and our coaches are basically twins. We changed his shocks after I saw an improvement in mine. Then two years ago after I put the Roadmaster sway bars on mine and told him the improvement, I got elected to install sway bars on his.

While talking to him the other day, I let him know my thoughts on the braces. Well, I got elected again. But really not a big deal to me.

The both of us are traveling to Colorado in two weeks, doing a lot of two-laning, so it will be the ultimate test. I'm ready!

Harry,

Our experience matches yours. We had a decent handling coach with the Koni's, sway bars, and TruCenter, but the cross braces made a significant improvement.

Bob

[deSanford]

Ok after reading the above posts I'm going to put my bars on this Tuesday. The rig is in storage now so afterward I will see if I can convince the DW to go on a trip. She likes staying home, and just came back from a 22 day vacation (Oceania Cruise and 3 nights in Lima Peru). We do have a 60 day mh trip coming up this July. I will then have one more mod on my bucket list for the mh and that is going over to Source Engineering and have their air bag release units installed. That helps on going in and out of driveways to prevent the elephant walk etc. deSanford

[MandG-Fun]

Originally Posted by Vanwill

I remember talking to one of you who had fabrication capability and was thinking of replacing his Sheppard steering box with a TRW adjustable type. I don't remember which of you that was, so would you please identify yourself and tell me if you've made any progress on that idea.

Someone contacted me asking if I knew of anyone who had made this swap.

Van, I had mentioned this in a response last year. I have not done this yet, wanted to get the x-braces and shocks done and see how the coach was driving. The x-braces have definitely added a level of stability but the play in the wheel still needs to be addressed. I've been wondering about the front p-rod and how much that may help in stabilizing. However, as you note in this thread... the Dynasty is less prone to wondering than the non-steel cage superstructure coaches. So, perhaps I have as much stability as I can expect out of a short wheel base coach. It certainly isn't bad, my only big concern left if the play in the darn Sheppard box.

At this point I'll probably defer that project until this winter when I have plenty of time to tear things apart and contemplate the mods necessary to switch to the TRW box. It would be great to find someone who has tackled this already so I don't have to pioneer a new trail.

So, sorry for all of the dialog and lack of content that you were hoping for. If the other guy decides to move forward or if anyone else has swapped out their steering box I'm curious to hear your thoughts, approach and lessons learned.

Glenn