Ride Height Adjustment

[hermanmullins]

I drive a 40 foot 2002 Monaco Dynasty on a Roadmaster chassis. There are 3 (three) Ride Height Adjusting rods, 1 (one) above the front axle in the center and 2 (two) in the rear just about the drive axle. I would like to raise the left side about two inches. It alway is a bit low on the left side under normal conditions. It does level ok.

Has anyone adjusted the rods? I know how to adjust the rods but do not know which direction to move the adjustment to either raise or lower the side.

Herman

[manholt]

2" ?  Me thinks you have too much weight on that side!  If you do get it raised that much, be careful with twist of chassis. 

[kaypsmith]

Herman, to make the left side higher, you will need to lengthen the rod on the left rear, or shorten the rod on the right rear, depending or which side is the correct height already. A little bit goes a long way, so lengthen or shorten accordingly.

Carl, the reason there is only three valves instead of four is to make sure you don't warp the chassis. The front bags are tied together using the air from the single height valve, this makes the two front bags follow the rear, if you raise either rear side the front will compensate.

[dickandlois]

Herman, I know you are informed about axle weight, but when was the last time you where weighed ?

When was the last time the ride height was checked ?

The REV Group height control valve looks just like this.

and this is the Freightliner ride height PDF File. 

Your chassis is made by ? ,but could be the same or slightly different 

Rich

ride height adj.pdf     One needs to read the information as the air pressure is  remover per instructions to adjust - not the safest place to work 

[hermanmullins]

Thanks Kay. Will block it up and try the adjustments. 

Herman 

[elkhartjim]

Do you have the specs on what the ride height should be? You could find you need to lower the high side instead of raising the side you think is low. I assume Roadmaster would have a specification on where/how to measure ride height similar to Freightliner.

[kaypsmith]

Herman, one thing that I forgot to mention is to check the rubber grommets on the rods and replace if needed, sometimes worn grommets will cause enough effect to change ride height as much as two inches. Good luck, don't remove those air lines while under there, and of course make sure it is blocked accordingly.

[wolfe10]

Absolutely start with the factory ride heights.  Set rear FIRST.  Then set front with the "average" side to side being to spec.

Let us know the before and after.

[hermanmullins]

Thanks Kay, had one brake several months ago. I had to laugh, the shop that fixed is, I was away from home, charged me $230.00. Labor approx $200.00 and parts $30.00. (I rounded the numbers). The part was the rubber grommet. I have found them on line for $1.94 each plus shipping.

The International Truck dealer has the kit, one rod and two grommets for $17.00. I am going to order 5 on line.

I will try to find the factory spec. on the Roadmaster chassis. Update to follow.

Herman

[wolfe10]

And, if you find that you don't have enough adjustment in the OE set up, these infinitely adjustable links work very well (come in two length ranges):

 

https://www.heightcontrolvalve.com/shopexd.asp?id=109

[kaypsmith]

I thought that I was through with the air bags and shocks this PM, cranked and aired for final inspection, only to find one more air leak. This time it was the Ferrell fitting on the left side, it was cracked and would not stay tight. Have to wait until daylight to finish the project now. I have improvised with plumbing hangers to get extra length in a tight. That is a good link Brett, thanks for sharing.

[hermanmullins]

Carl,

Sorry I didn't respond to your comment on the appropriate 2 inch from one side to the other. A 2" adjustment on the rear could only mean maybe a quarter of an inch at the adjusting rod. 

I will get the factory specifications before I adjust anything. 

I will let you know the results.

Herman 

[rsbilledwards]

 

When I went after the leaks in my coach and what a project, I eliminated many of the nut and ferrel fittings. They make any service a long job when they need to be disassembled and then reassembled. It is easy to over tighten them. This coach only had 12,000 miles on it and would leak down in an hour or so and no noise I could hear.  Apparently the chase began earlier by additional wrench work, distorting the ferrels further. 

I replaced all that I could with "Push to Fit" fittings. These fittings have some limitations not in their ability but as to type. I think this is correct on usage. There are two types of these fittings,  one is all brass and DOT approved and the others are part brass or other material and plastic and not DOT approved. The internal seal up it appears,  is the same. The DOT rated fittings are more expensive, and a lot more depending on where one buys them. The DOT units should be used where they are associated with rigs having air brake systems. I suspect there is less likelihood of a failure. I have used both as I do not have air brakes and air is utilized only for the suspension. The sizes used are 1/4 and 3/8 and accept any of the smooth plastic air line hoses. By changing only these connection points I eliminated most of the air leaks. I went back later and installed the Source Engineering suspension air flow restrictor valves at each air bag. I just cut a small section from the appropriate line and pushed the ends into the valves and more of the leaking stopped. I can make only one supposition on this as there was a pin hole leak in a section or possibly two I cut out. Never the less now the coach stays up for a week before settling down on his stops.

I will add here too that the restrictor valves made an enormous difference in the way the coach handled cornering by slowing the lean. 

[elkhartjim]

7 hours ago, hermanmullins said:

Carl,

Sorry I didn't respond to your comment on the appropriate 2 inch from one side to the other. A 2" adjustment on the rear could only mean maybe a quarter of an inch at the adjusting rod. 

I will get the factory specifications before I adjust anything. 

I will let you know the results.

Herman 

You probably know this but when you get the measurements make sure they tell you where to take the measurements.

[wolfe10]

55 minutes ago, elkhartjim said:

You probably know this but when you get the measurements make sure they tell you where to take the measurements.

Yup, absolutely no standards here.

Some measure from a given place on the body to the ground.

Some from suspension member to chassis rail.

Etc.

Anytime you get your ride height specs, as Jim said they will include both a DIMENSION/DISTANCE and a "measure from point A to point B".

[hermanmullins]

Thank to you both.

Herman

[alford316]

Hello, I need to do a ride height adjustment but I'm not really sure where to "block" for safety.  Almost everything I read suggests blocking the chassis for safety. I'll all about safety when I'm under that thing.  Can someone explain what and where I should block this thing so I will be safe?  Thanks!

2005 Monaco Knight

[wolfe10]

alford316,

 

Welcome to the FMCA Forum.

Assume your chassis has two ride height valves in the rear and one in front.

First, a question.  Can you access the rear ride height valves from outside the coach or do you have to crawl under?  If from outside, at least the first adjustment (rears) requires no safety stands.

For the front (again, assuming one in the center of the coach) you absolutely need safety stands.  Only exception is to let all the air out of the suspension and verify that you can still safely crawl under the coach.  Yes, on some you can (some coaches and some "body thicknesses").

Another alternatives to safety stands is to drive all wheels up on 2X10's (still level) and verify that you have safe room with all the air out of the suspension.

[alford316]

Thanks sir!  Great idea with driving on to the wood blocks. I'm almost positive there would be room underneath with air released and double stacked 2x10's under each tire. Another thought, would the hydraulic jacks let down to an inch of the floor protect me in case something crazy happened?  I would think so, but I'm new to all of this and there is a lot I don't know.

On a side note, Wolf10, I have learned a lot from many of your posts.  Thank you!

 

[richard5933]

Hydraulic jacks are generally not accepted as a safety backup. Also important to remember is that you have to know where on the chassis to support the coach if you are going to place jack stands. You are not trying to support the axles or any part of the suspension - you are trying to support the coach chassis and body. There are specific points rated to support the chassis. Put the jack stands in other places and they might just punch holes in the floor of the coach as it drops down.

Best bet is to call the chassis/coach support phone number and get specifics on where it's recommended that your specific layout be supported while you are underneath.

[rayin]

When adjusting ride height, it's best performed on a level surface of course. Driving onto wood planks(mine are 3 high 2X8's) is best to obtain room to work underneath.

Herman, I wonder if this  website will have the ride height specs for your chassis?https://www.monacocoach.com/chassis-questions

[hermanmullins]

Thanks, I got them there. I found that you take the measurement off the air bags located between the drive axle and the tag axle. I can't remember but I think in measurement was 8.25 inches. I would have to go back to my notes. 

Thanks, 

Herman 

[wolfe10]

Yes, on the 8 outboard air bag suspensions, you need to verify if the ride height is measured on the front or rear bags/in front of or behind the wheel.

I know on Foretravel 8 bags, you measure ride height on the bags TOWARD THE CENTER OF THE COACH= front of rear and rear of front.

[hermanmullins]

1 hour ago, wolfe10 said:

front of rear and rear of front.

Easy for you to say.😁

Herman