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Dynasty wheel alignment


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My Motorhome is a2002 Monaco Dynasty model 36SL single rear axle. I recently replaced the sheppard steering gear box with a trw adjustable steering gear box which eliminated play in the steering wheel. All steering components are tight ,it has new tires and good shocks but it still has some wander at highway speeds. The next thing i will do is to check the alignment settings for the best straight ahead stability. 

I cannot find the manufactures original alignment specifications - does anyone know what they are?  I would also like to know what others have as their actual settings to give  the 8R chassis the best straight ahead stability. The present settings are : Toe +1/8 degree    Camber L +1/8 degree  R-1/8 degree    Caster L+4  7/8 degree   R+5  3/4 degree. I think it should have a couple more degrees positive Caster. What do  others think?

Joe Klasch  o2 Dynasty

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Agree with notes above but I found the alignment recommendations for my 08 Beaver Marquis in the chassis section of the owners manual !!  very different chassis as  mine is a tag and heavier than the Dynasty.. my settings are for reference. :

Camber left 1/8degree +/- 7/16 degree   Right  -1/8degree  +/- 7/16th

Caster  Left  5degrees +- 1 degree    Right 7degrees +- 1 degree

total toe   1/16"  (0.08 degree)

 

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7 minutes ago, bill4029 said:

Agree with notes above but I found the alignment recommendations for my 08 Beaver Marquis in the chassis section of the owners manual !!  very different chassis as  mine is a tag and heavier than the Dynasty.. my settings are for reference. :

Camber left 1/8degree +/- 7/16 degree   Right  -1/8degree  +/- 7/16th

Caster  Left  5degrees +- 1 degree    Right 7degrees +- 1 degree

total toe   1/16"  (0.08 degree)

 

 

13 minutes ago, bill4029 said:

Agree with notes above but I found the alignment recommendations for my 08 Beaver Marquis in the chassis section of the owners manual !!  very different chassis as  mine is a tag and heavier than the Dynasty.. my settings are for reference. :

Camber left 1/8degree +/- 7/16 degree   Right  -1/8degree  +/- 7/16th

Caster  Left  5degrees +- 1 degree    Right 7degrees +- 1 degree

total toe   1/16"  (0.08 degree)

 

My experience with alignment’s is always have the right caster sit more than the left. Reason being most roads have a crown in them.  Driving in the right lane it will drive to the right of caster is same on both sides. Unless you take the coach to a reputable big rig alignment shop you can’t adjust camber and caster very easy 

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10 hours ago, highsierra37@att.net said:

Dwight

I have also recently installed the Watts link system on the rear of my motorhome . Every thing i have done has made it drive better. I am now up to the last thing which is alignment.

Joe Klasch

My experience has been that the Watts should be installed on the front first. If you only have one Watts link it should be on the front. If you do not have a Watts link on the front then you should do that before wasting time and money on an alignment. An alignment will have zero effect on wandering.  The only time an alignment can reduce wandering is if your wheels are toed out. You can adjust the toe with a friend and a tape measure. Wandering is caused by your wheels not going where you point them and is usually caused by worn or loose steering components. In your case the problem is caused by slop in the trailing arms and the fact that you have a single Panhard bar. That single Panhard bar forms a fulcrum point allowing the front H-frame to pivot around the Panhard bar tie point at the H-frame. This is a result of the H-frame being mounted on 4 air bags that are very flexible by design. The Roadmaster chassis falls short in the fact that 4 trailing arms and a single Panhard bar will not completely stabilize the H-frame. Since your front axle is attached to the H-frame then your front tiers are attached to the H-frame. When your H-frame wiggles so do your front tires. If your coach is cruising down the highway at 60 MPH your front tiers are covering a distance of 88 feet per second. That converts to 1056 inches per second. If for what ever reason your front H-frame wiggles around the Panhard bar connection to the left or the right by 0.1 degrees then the direction of your front wheels will point 0.1 degrees away from your intended direction of travel. Assuming 1056 inches along the hypotenuse of the right triangle formed by the new wheel direction and the intended path of the coach then the Sine of 0.1 x 1056 = 1.84 inches. That means that in one second your coach will deviate  1.84 inches from your intended direction. In two seconds it will be off by 3.68 inches. 

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The alignment specs are also listed in my 2002 Windsor Manual. 

I am not an expert on this but when I bought my coach the front tires had a bad cupping wear pattern.   These were Firestone tires which were known to  have this problem.  Driving it home from Florida there was excessive vibration.   One of the first things I did after getting a complete inspection and service from Cummins was to get new tires put on the front and then went immediately to an alignement shop that was recommended by Buddy Gregg of Knoxville.  The shop said that I did have a problem, had to bend the axle to fix.  I've put +50K miles on the rig since then and the front tires show no signs of wear, although they are now aged out and will need replacing. 

My coach drives straight and true, no wondering.  I guess I got lucky and don't see a need for any modifications. 

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It probably wouldn’t hurt to have castor up around 6 but I don’t think it would cure your wander.  A 36 is pretty short. 
 

You can imply some castor like stability with a Safe-T-plus. I have one on my Dynasty and had it on a 38 Diplomat before that. They definitely add stability. 
 

The other thing that may help is a watts link which I’m sure others will comment on that have them. 
 

Bill G

06 Dynasty

 

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Bob

You gave a good explanation of the Monaco watts link. We started with the rear cross bars to see what effect we would get by stiffing up the rear . It has helped quit a bit in stopping the tail wagging the dog effect caused by the very heavy suspended weight of the engine and transmission.

I will be installing the front watts link in the near future.

Joe Klasch   02 Dynasty

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I was under the impression the S chassis didn’t require modifications to prevent wandering. I haven’t noticed wandering with my coach. I’ve owned it 2.5 years and put 23k miles in it. I don’t believe any mods were made before I purchased it. 

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  • 1 month later...
On 7/17/2020 at 5:53 PM, philcarrell said:

 

My experience with alignment’s is always have the right caster sit more than the left. Reason being most roads have a crown in them.  Driving in the right lane it will drive to the right of caster is same on both sides. Unless you take the coach to a reputable big rig alignment shop you can’t adjust camber and caster very easy 

That is my problem.  Finding a competent alignment shop to handle rr8r chassis alignment in my area of southern California.   Any one find a place that had success  within 50 or even 100 miles of Ontario, California?

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13 hours ago, TomV48 said:

That is my problem.  Finding a competent alignment shop to handle rr8r chassis alignment in my area of southern California.   Any one find a place that had success  within 50 or even 100 miles of Ontario, California?

Ask the local class 8 truck dealers where they get their frame work done. Do some phone interviewing.

Paul A

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  • 3 weeks later...
21 minutes ago, woodylmiller said:

Commercial Goodyear tire centers usually have the ability to do these alignments.  What about Love's truck stops?

Woody Miller

09 Dynasty Regal IV

I seem to recall Speedco no longer services motorhomes. 

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1 hour ago, woodylmiller said:

Commercial Goodyear tire centers usually have the ability to do these alignments.  What about Love's truck stops?

Woody Miller

09 Dynasty Regal IV

I don’t think you can adjust camber on the straight axle. 
 

To adjust Castor takes shims. I think I have mine up around 6 degrees . 
 

The toe in can probably be checked with a tape measure .  
 

Josams in Florida would be a good one to take it to. 
 

 

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  • 2 years later...

My Diplomat 43DFT was pulling to the right so I took it in to Velocity Truck center and requested a 3-axle alignment. When I picked it up the only thing they adjusted was the toe-in and centered the steering wheel saying there was no adjustment on the caster or thrust angle. I agree the drive axle has no adjustments but surely the steering axle has some means of adjusting the caster. It appears you guys have dealt with this so can anyone provide information on the procedure as both sides are setting at 3.6 and 3.3 which way off from factory settings.

 

Edited by ronwhitehurst
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On 9/5/2020 at 7:45 PM, TomV48 said:

That is my problem.  Finding a competent alignment shop to handle rr8r chassis alignment in my area of southern California.   Any one find a place that had success  within 50 or even 100 miles of Ontario, California?

Well, in the end, I took it to Pete's tire in Fontana and they took a look at it and told me their guy in Corona was where I needed to be.   I let Pete's Tire and road service in Corona align it. 

 According to the report he was able to tweak the caster a little bit by somehow using shims.  Sadly I wasn't allowed in the shop so I couldn't see what he really did.  He definitely straightened out the toe in and the darn thing goes down the road much better now.

Good news is he charged me a total of only about $140.   While the Big Time RV repair services that told me they could do the alignment, wanted generally $200 to evaluate the alignment  (Pete' s in Fontana put it on the rack and let the computer read the numbers-  but only charged me $60 for setting it up and giving me the printout). And then those two, unnamed, Big Time RV repairs wanted $200 per axis that they adjusted. So theoretically that alignment could cost me $800 and neither of those shops told me a story that convinced me they knew what the hell they were doing any better than Pete's truck shop.

So far so good I'm watching tire wear on my new tires, because after all if it goes straight down the road and the tires wear right it's a good alignment by my standards.

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