Need help for continuing to modify Suspension

[JDCrow]

Thanks everyone, getting around and watched the TRW video. 

thanks Van and Bob for never growing tired of explaining and helping. I know you both must have repeated this over a thousand times. 
 

 

 

[JDCrow]

Couple of pics from the underside. I don’t see any glaring cracks, bad bushings, bent arms, etc.

I will say after reading comments and my limited knowledge that having these large “trailing” arms with nothing in front of the axle to keep straight with the frame seems just off. The pan hard rod and the watts are both on the back side of the front axle. 

[vanwill52]

JD, I don't see anything obviously wrong.  You could slide the outboard mounts for the Watts link arms toward the center of the coach on both sides to cause the Watts pivot bar in the center to be more nearly vertical, but I have never seen that make any difference.

It is always preferable to mount the Watts link as far from the Panhard rod as possible, which would be near the front of the H-frame.  But on 98% of the coaches, the only practical place to mount it is where yours is--behind the Panhard rod.

[JDCrow]

4 minutes ago, vanwill52 said:

JD, I don't see anything obviously wrong.  You could slide the outboard mounts for the Watts link arms toward the center of the coach on both sides to cause the Watts pivot bar in the center to be more nearly vertical, but I have never seen that make any difference.

It is always preferable to mount the Watts link as far from the Panhard rod as possible, which would be near the front of the H-frame.  But on 98% of the coaches, the only practical place to mount it is where yours is--behind the Panhard rod.

Yeah that’s where the instructions  had us put the Watts. Doesn’t it seem that something should be forward of the axle towards the front to help center it? 

[vanwill52]

JD, you can still slide the outboard clamps toward the coach center, so the Watts lever is nearly vertical, not that it will make much, if any, difference in how it works.  You might have to notch the corner braces of the H-frame slightly to clear moving the outboard clamps inward.

The worst, most road-wild coach I ever drove was my first Monaco, a 1993 Dynasty with Kohler LPG generator, which did not roll out on a slide.  That was the coach that got me to delve into what was actually causing all the wandering...that is, AFTER I followed the "herd wisdom" that shocks could cure wandering.  The truth is that shocks do ABSOLUTELY NOTHING to prevent wandering...except between the ears of the person who just shelled out a small fortune for them.  And the shocks certainly did nothing for my 1993 Dynasty wandering.   All they did was make the ride harsher.

When I finished with it, that was the absolute BEST driving/handling coach I ever owned, including my present 2000 Dynasty.  The 1993 Dynasty never got a Watts link.  I had not thought of that at the time.   The 1993 Dynasty was the last year that X-bars could be installed FRONT and REAR.  I welded small tabs with a hole for a 1/2" bolt near both ends of the two lower trailing arms front and rear.  My X-bars were 1/2" diameter steel bars, threaded at each end for small Heim joints.  Yup, they worked perfectly. If you think about it, the X-bars perform in TENSION--when one bar is being "stretched" the other is lightly loaded in compression.  Even 1/4" X-bars might have worked on that 1993 Dynasty.

The idea of the Watts link came to me as I was trying to come up with something that would work for the front of coaches that had a generator in the way and prevented the use of X-bars in the front (ALL coaches 2004 and newer).  After the experience with the 1993 Dynasty, I decided X-bars were best for both front and rear, but simply could not be fitted to most post-1993 coaches.  The X-bars always acted at the extreme ends of the trailing arms, where they were best at preventing the H-frame from "squirming" under side loads.

But I never came up with a way I liked for putting X-bars on the front, hence the development of the Watts link application.  And yes, the farther the Watts link is located from the Panhard bar, the better it controls the H-frame.  But it makes a huge improvement, even if it is closer than optimal to the Panhard bar.  Another consideration in the Watts link development was to make something that did not require welding. 

On my 2000 Dynasty, I WELDED the Watts link assembly to attach to the FRONT crossmember of the H-frame, nearly triple the distance from the Panhard bar as it would have been had I mounted it overlaying the front jack mount.  That type installation is possible on most coaches, and surely performs better, but requires some extensive welding and extra steel tubing and flat bar and additional machining.  I have a fully equipped machine shop at my home.

[JDCrow]

10 hours ago, vanwill52 said:

JD, you can still slide the outboard clamps toward the coach center, so the Watts lever is nearly vertical, not that it will make much, if any, difference in how it works.  You might have to notch the corner braces of the H-frame slightly to clear moving the outboard clamps inward.

The worst, most road-wild coach I ever drove was my first Monaco, a 1993 Dynasty with Kohler LPG generator, which did not roll out on a slide.  That was the coach that got me to delve into what was actually causing all the wandering...that is, AFTER I followed the "herd wisdom" that shocks could cure wandering.  The truth is that shocks do ABSOLUTELY NOTHING to prevent wandering...except between the ears of the person who just shelled out a small fortune for them.  And the shocks certainly did nothing for my 1993 Dynasty wandering.   All they did was make the ride harsher.

When I finished with it, that was the absolute BEST driving/handling coach I ever owned, including my present 2000 Dynasty.  The 1993 Dynasty never got a Watts link.  I had not thought of that at the time.   The 1993 Dynasty was the last year that X-bars could be installed FRONT and REAR.  I welded small tabs with a hole for a 1/2" bolt near both ends of the two lower trailing arms front and rear.  My X-bars were 1/2" diameter steel bars, threaded at each end for small Heim joints.  Yup, they worked perfectly. If you think about it, the X-bars perform in TENSION--when one bar is being "stretched" the other is lightly loaded in compression.  Even 1/4" X-bars might have worked on that 1993 Dynasty.

The idea of the Watts link came to me as I was trying to come up with something that would work for the front of coaches that had a generator in the way and prevented the use of X-bars in the front (ALL coaches 2004 and newer).  After the experience with the 1993 Dynasty, I decided X-bars were best for both front and rear, but simply could not be fitted to most post-1993 coaches.  The X-bars always acted at the extreme ends of the trailing arms, where they were best at preventing the H-frame from "squirming" under side loads.

But I never came up with a way I liked for putting X-bars on the front, hence the development of the Watts link application.  And yes, the farther the Watts link is located from the Panhard bar, the better it controls the H-frame.  But it makes a huge improvement, even if it is closer than optimal to the Panhard bar.  Another consideration in the Watts link development was to make something that did not require welding. 

On my 2000 Dynasty, I WELDED the Watts link assembly to attach to the FRONT crossmember of the H-frame, nearly triple the distance from the Panhard bar as it would have been had I mounted it overlaying the front jack mount.  That type installation is possible on most coaches, and surely performs better, but requires some extensive welding and extra steel tubing and flat bar and additional machining.  I have a fully equipped machine shop at my home.

Awesome! I wish I could think like that. My brain travels in different directions. I think my grandfather and you would have been fast friends, though his temper made him unbearable most times, a little Jack D and look out.

 

Anyway, got the safety steer off. Got the tie rod out and yes there was some slight play in the pitman arm. I had to push a bit, but there was 1/4”+. I have no end Wrench that would fit in between the box and plate. Remembered my trusty crescent wrench set and done. 
 

I tightened it back up, and went upstairs to the steering wheel, and still felt Ike it had a slight bit of play till you could feel the system engage. So I snugged it up another  1/4 turn on the adjustment screw and there is no play left to right. It moves the tires the moment you turn the steering wheel. 
 

Thanks all, off to Havasu tomorrow and will report 

Edited October 20, 2021 by JDCrow

[Frank McElroy]

Van Great explanation of how the TRW vs Sheppard gearboxes work. From experience, I'm finding that my TRW gearbox needs adjustment about every 50,000 miles.  Once adjusted - wow - like driving my tag axle coach when it was new.  Your technical explanation is the best I've ever seen.  Thanks for sharing to the group.

[vanwill52]

2 hours ago, Frank McElroy said:

Van Great explanation of how the TRW vs Sheppard gearboxes work. From experience, I'm finding that my TRW gearbox needs adjustment about every 50,000 miles.  Once adjusted - wow - like driving my tag axle coach when it was new.  Your technical explanation is the best I've ever seen.  Thanks for sharing to the group.

Quite a compliment, coming from you, Frank!  You are one of the most technically competent folks in this group. Thanks!

[Bob Schmeckpeper]

My O My. Do I have a lot to learn.  Just figured that was just the way it was with these old rigs. Never had what I felt was a severe problem,  but it always takes a little correcting to keep the old girl centered in the lane. Side wind hitting 380 sq feet will push you around. If the wind gets to strong  i just figured it's time to slow down or find a parking spot till it calms down a little.  Qust from passing semis. Push me around a little.  I just grap the wheel a little tighter till they pass. Could I be so Nivea? Lol (yep)

You guys have pointed me in a whole new direction on how to spend a bunch more on this rig. 

Looks like its time to spend some time on the web.  Can you point me in the right direction were to start looking?

JD, if your still in Yuma we would love to see what you have done with your rig. If you don't have the time for visitors or have hit the road again.  Safe travels & hope your major problems are behind you.  

 

[JDCrow]

Bob, just got to Havasu, about 45 mins ago. What should have been 3 hours took 4. 
 

Van and other Bob. Taking off the safety Steer and adjusting the Box did nothing. I’ve given it thought on how to explain. 
 

The steering acts like a hydraulic Ram. If you push it one way, it goes that way, and keeps going with force. So much so that you have a o pull it back to stop it. But once you push on the other way to stop it, it goes that way until you push it the other way. 
 

Same with the coach, it never goes straight down the road. It will go right until I turn the wheel and the box kicks in and then it goes left, and keeps going left till I turn it right, then it keeps going right till I pull it back left, then it keeps going left…..over and over 

So thinking about my alignment given what you both talked about, because there’s not much else to do? 
 

 

[Cubflyer]

Driving ease is all about keeping the wheels going straight down the road 'naturally' not by the driver (with the steering wheel).... alignment is first, getting it right and keeping that alignment (not having the suspension 'shifting' under you) is next.  That is what the x-bars and watts link do (because a single panhard rod on a H frame on long drag links will NOT).

The sway bar helps keep the wheels going straight down the road because it reduces body roll which 'inputs' steering due to the fact the steering wheel and box are mounted to the frame and the tie rod is on the H frame (suspension).

Sounds to me like you need to assure your caster and toe in/out are correct and add a sway bar (to the front) and see if that helps...   My experience is that I installed tires, shocks and the front sway bar..... helped a lot but the coach still 'wandered'.  Installed the front watts and the rear cross bars and the coach drives great...... not without some 'looseness', not quite 'on rails' but darn close and darn good compared to before. 

 My steering box is loose, but since the coach runs straight and is little bothered by passing trucks and uneven road surfaces it's no big deal.   Last summer, driving across the country I encountered areas where the  road was being resurfaced, where one lane is an inch or two higher than the other... I crossed over between them without any fear..... I have been tossed around worse doing that in cars and SUV's....

Ken

Edited October 21, 2021 by Cubflyer

[JDCrow]

39 minutes ago, Cubflyer said:

Driving ease is all about keeping the wheels going straight down the road 'naturally' not by the driver (with the steering wheel).... alignment is first, getting it right and keeping that alignment (not having the suspension 'shifting' under you) is next.  That is what the x-bars and watts link do (because a single panhard rod on a H frame on long drag links will NOT).

The sway bar helps keep the wheels going straight down the road because it reduces body roll which 'inputs' steering due to the fact the steering wheel and box are mounted to the frame and the tie rod is on the H frame (suspension).

Sounds to me like you need to assure your caster and tie in/out are correct and add a sway bar (to the front) and see if that helps...   My experience is that I installed tires, shocks and the front sway bar..... helped a lot but the coach still 'wandered'.  Installed the front watts and the rear cross bars and the coach drives great...... not without some 'looseness', not quite 'on rails' but darn close and darn good compared to before. 

 My steering box is loose, but since the coach runs straight and is little bothered by passing trucks and uneven road surfaces it's no big deal.   Last summer, driving across the country I encountered areas where the  road was being resurfaced, where one lane is an inch or two higher than the other... I crossed over between them without any fear..... I have been tossed around worse doing that in cars and SUV's....

Ken

Thanks Ken, so I have Front watts and rear cross bars. New steers before we came down. At your advice, I ordered a front sway bar and it will be here Friday to install over the weekend. I also have new rear tires being delivered down here as well.  Will get them installed and try and get an alignment as well.   The rears are right at 5 years old. However I believe the coach sat for a long time based on the condition I bought it in. So I’m not sure if they sat under inflated and maybe put stress on the plies. For peace of mind I’ll change them out.
 

I did notice slight wear on the outside edge of the drivers side tire. It was in the flashlight view and will look at it better in the morn. 
 

Thanks much! 

[vanwill52]

JD, although it is still possible, in nearly 200 coaches I've dealt with, I have never heard of a single instance in which alignment improved wandering one iota.  It's true that their are two alignment specs that could exacerbate (not CAUSE) wandering.  They are toe-in and caster.  When you have an alignment done on a solid front axle chassis of any kind, the only adjustment made 95% of the time is toe-in. 

If toe-in is too small, or toe-"out" actually exists, you can easily check it with a tape measure.  Jack each front wheel off the ground, rotate it while making a soapstone mark in the center of the tread area.  Use a tape measure and a helper to measure the distance between those lines at the back of the tires, and again at the front.  The front measurement should be slightly less than the rear.  That is "toe-in".  If there is "toe-OUT", that MIGHT cause some wandering.  You adjust it yourself with the RH/LH threaded relay rod that connects the two spindles.

The other alignment spec affecting tracking is caster.  If you had negative caster, that would present a tracking problem.  But caster is "built-in" to the mounting pads of the chassis where the axle attaches.  It is easy to see with the naked eye.  It can only be changed by adding tapered shims between the chassis mounting pads and the axle.  You might read multiple instances where someone deliberately increased caster (more positive) to cure a wandering condition, because they read about it in "Alignment 101" at trade school.  But, again, the improvement is much like the improvement in wandering from changing shocks--it exists between the ears of the person who went to the trouble and expense to do it.

The last alignment spec is camber.  Camber is "built-into" the axle.  It can only be changed by using powerful hydraulic equipment to BEND the axle to a new camber spec.  Your camber will never need adjustment unless the vehicle has been in a serious accident which bent the axle.  Most alignment shops are not equipped to change camber.  Josam's, probably the best large-vehicle alignment shop in the country, can change camber...but I bet they very seldom do it.

When you get an alignment done, you are generally paying $300 to set toe-in.

The bottom line is that there might be dozens of contributing factors that make a TINY improvement in wandering, but the basic problem is simply that the "platform" (H-frame) to which both your front and rear axles are attached is "squirming" around under your coach because it it not rigidly restrained from doing so.  The reason is the H-frame is attached to the chassis with long, spindly trailing arms with compliant bushings in each end, and the entire assembly is constrained from rotating under the coach with a single Panhard rod.  That is a near-geometric impossibility.  Had the chassis been originally designed with TWO Panhard rods on each H-frame, the wandering problem would never have existed.

The simple reason your coach wanders is that it is going where its wheels are pointed...NO OTHER REASON.  Force your wheels to stay pointed straight ahead and there is NO wandering.  NO shock absorber will do that.  NO steering stabilizer will do that.  To accomplish that on a Roadmaster chassis, you must stabilize the H-frames.  The best way is with X-bars, which accomplish what the missing SECOND Panhard rod WOULD have done.  When X-bars are not possible, the Watts link is the "second-best" alternative.  And just as would have happened with two Panhard rods, the further they are apart, the better they work.  Since my coach was not a terrible wanderer, when I installed my Watts link in the front, I went to great lengths to mount it as far from the Panhard bar as possible...to be sure I got a result that was not just "between my ears".  That required machining parts and welding in additional components.  My short 36' coach is a two-finger driver, even when being passed by a tractor-trailer...and so was my "cured" 1993 Dynasty, which originally felt as if you could not guide it in a straight line if your life depended on it.

JD, in your case, I can only suggest that you investigate mounting your front Watts link as far from the Panhard rod as possible.  One enterprising fellow on iRV2 actually added a second Panhard rod and it was, of course, successful.  That was my first thought when I realized I could not fit X-bars to my coach, but decided at the time it was beyond my capabilities at the time--I had no plasma cutter, and my welding equipment was not powerful enough.

If you are ever in the Southeast, I will be glad to look at your coach for you, although I stopped installing X-bars and Watts lengths years ago, as soon as I had proven to my satisfaction they were a solution.

[JDCrow]

55 minutes ago, vanwill52 said:

JD, although it is still possible, in nearly 200 coaches I've dealt with, I have never heard of a single instance in which alignment improved wandering one iota.  It's true that their are two alignment specs that could exacerbate (not CAUSE) wandering.  They are toe-in and caster.  When you have an alignment done on a solid front axle chassis of any kind, the only adjustment made 95% of the time is toe-in. 

If toe-in is too small, or toe-"out" actually exists, you can easily check it with a tape measure.  Jack each front wheel off the ground, rotate it while making a soapstone mark in the center of the tread area.  Use a tape measure and a helper to measure the distance between those lines at the back of the tires, and again at the front.  The front measurement should be slightly less than the rear.  That is "toe-in".  If there is "toe-OUT", that MIGHT cause some wandering.  You adjust it yourself with the RH/LH threaded relay rod that connects the two spindles.

The other alignment spec affecting tracking is caster.  If you had negative caster, that would present a tracking problem.  But caster is "built-in" to the mounting pads of the chassis where the axle attaches.  It is easy to see with the naked eye.  It can only be changed by adding tapered shims between the chassis mounting pads and the axle.  You might read multiple instances where someone deliberately increased caster (more positive) to cure a wandering condition, because they read about it in "Alignment 101" at trade school.  But, again, the improvement is much like the improvement in wandering from changing shocks--it exists between the ears of the person who went to the trouble and expense to do it.

The last alignment spec is camber.  Camber is "built-into" the axle.  It can only be changed by using powerful hydraulic equipment to BEND the axle to a new camber spec.  Your camber will never need adjustment unless the vehicle has been in a serious accident which bent the axle.  Most alignment shops are not equipped to change camber.  Josam's, probably the best large-vehicle alignment shop in the country, can change camber...but I bet they very seldom do it.

When you get an alignment done, you are generally paying $300 to set toe-in.

The bottom line is that there might be dozens of contributing factors that make a TINY improvement in wandering, but the basic problem is simply that the "platform" (H-frame) to which both your front and rear axles are attached is "squirming" around under your coach because it it not rigidly restrained from doing so.  The reason is the H-frame is attached to the chassis with long, spindly trailing arms with compliant bushings in each end, and the entire assembly is constrained from rotating under the coach with a single Panhard rod.  That is a near-geometric impossibility.  Had the chassis been originally designed with TWO Panhard rods on each H-frame, the wandering problem would never have existed.

The simple reason your coach wanders is that it is going where its wheels are pointed...NO OTHER REASON.  Force your wheels to stay pointed straight ahead and there is NO wandering.  NO shock absorber will do that.  NO steering stabilizer will do that.  To accomplish that on a Roadmaster chassis, you must stabilize the H-frames.  The best way is with X-bars, which accomplish what the missing SECOND Panhard rod WOULD have done.  When X-bars are not possible, the Watts link is the "second-best" alternative.  And just as would have happened with two Panhard rods, the further they are apart, the better they work.  Since my coach was not a terrible wanderer, when I installed my Watts link in the front, I went to great lengths to mount it as far from the Panhard bar as possible...to be sure I got a result that was not just "between my ears".  That required machining parts and welding in additional components.  My short 36' coach is a two-finger driver, even when being passed by a tractor-trailer...and so was my "cured" 1993 Dynasty, which originally felt as if you could not guide it in a straight line if your life depended on it.

JD, in your case, I can only suggest that you investigate mounting your front Watts link as far from the Panhard rod as possible.  One enterprising fellow on iRV2 actually added a second Panhard rod and it was, of course, successful.  That was my first thought when I realized I could not fit X-bars to my coach, but decided at the time it was beyond my capabilities at the time--I had no plasma cutter, and my welding equipment was not powerful enough.

If you are ever in the Southeast, I will be glad to look at your coach for you, although I stopped installing X-bars and Watts lengths years ago, as soon as I had proven to my satisfaction they were a solution.

Thanks Van, I appreciate you taking time to help. I’d love to venture over, not sure we’d make it! 
 

I will take a closer look at the front H-Frame and see if I can surmise what you are saying. There’s and air tank in front of the front axle as well as the hard mounted genset. 

[JDCrow]

Crawled under and it looks like if I had the same framework fabed up similar to what the front Jack is like, then I could move the Watts to in front of the air tank and then the front half of the H frame would be stabilized instead of the rear. 
 

Because of the Arms, I don’t think I could get a pan hard rod to fit in there? 

 

[JDCrow]

Contacted a Fab Shop here in Havasu. Taking it in Monday morn to see about a simple frame to move the Watts to the Front 

[vanwill52]

2 minutes ago, JDCrow said:

Contacted a Fab Shop here in Havasu. Taking it in Monday morn to see about a simple frame to move the Watts to the Front 

Essentially, what I did was reinforce the 1-1/2" vertical supports for the rear of the genny with 1-1/2 x 3 rectangular tubing, then triangulated the assembly with a 3/8 x 5 flat bar connecting it all together.  the flat bar was the mount for the Watts pivot bar assembly.  Depending on your coach, there could be other ways to do it.

[Scott 61]

I have a question on JD's recent picture is the 4th picture showing the panhard bar thank you

[JDCrow]

14 minutes ago, Scott 61 said:

I have a question on JD's recent picture is the 4th picture showing the panhard bar thank you

For me or Van? 

[JDCrow]

49 minutes ago, vanwill52 said:

Essentially, what I did was reinforce the 1-1/2" vertical supports for the rear of the genny with 1-1/2 x 3 rectangular tubing, then triangulated the assembly with a 3/8 x 5 flat bar connecting it all together.  the flat bar was the mount for the Watts pivot bar assembly.  Depending on your coach, there could be other ways to do it.

Ok perfect! Thanks for the cut list and mock up. I have to make this simple for the guy. I don’t think it should take him to much if he has a decent shop 

Edited October 21, 2021 by JDCrow

[Scott 61]

I'm a novice just trying to figure this out where the panhard bar is on my rig thank you

[JDCrow]

6 minutes ago, Scott 61 said:

I'm a novice just trying to figure this out where the panhard bar is on my rig thank you

You have Roadmaster suspension? They still used it, and didn’t ditch it LOL 

Anyway, the pan hard is behind the Front axle, Body frame to H frame 

Edited October 21, 2021 by JDCrow

[JDCrow]

20 minutes ago, Scott 61 said:

I'm a novice just trying to figure this out where the panhard bar is on my rig thank you

Hey also, is your coach pre-emissions? It has an EGR? 

[Jim McFarland]

In my opinion, my safety Steer would be one if the last things I would remove from my coach. It works on side winds and trucks coming by you and if you should have a blow out. Just my thoughts. 

Jim

2009 Monaco 41 DFT

[JDCrow]

32 minutes ago, Jim McFarland said:

In my opinion, my safety Steer would be one if the last things I would remove from my coach. It works on side winds and trucks coming by you and if you should have a blow out. Just my thoughts. 

Jim

2009 Monaco 41 DFT

It will most likely go back on. I am really just trying to figure out what does what. If the fab shop can weld in a structure to move the Watts forward of the axle, I’ll have the H frame pinned on both front and back. Well double on back as the sway bar just got delivered. 

Edited October 21, 2021 by JDCrow