Wandering Coach

[Slojoe72]

Just wondering how I can improve the handling of my ride. 1999 holiday rambler, 40' 350 cummins diesel pusher 36000 miles.
So while driving it just seems like I'm always chasing it, not terrible but always feel like I'm steering it. So here's the issue .... I bought it to tow my race car trailer with. So I have a 32' enclosed trailer attached. Soooo when I'm towing and chasing the motorhome, the trailer seems to all over the place.
Wonder about shocks... Suspention bushings.... Alignment?? Something?

[10forty2]

Disclaimer first.... to the OP... my coach is on the F53 chassis, and I'm not familiar with your chassis, so what I am typing may not apply to yours:

With that said, when we first bought our 1999 HR Endeavor, I thought it was me that just simply couldn't drive or that I was just not familiar with driving such a big rig, even though I had been driving firetrucks for 20 years. After I got to looking into the situation further, since I was experiencing pretty bad body roll (sway) and the thing wandered all over the lane, I found a few items that were worn out. First, I found that my sway bar bushings were practically gone. Replaced those and the body sway went away. I then took my rig to a big truck alignment shop for an alignment and was told that my king pins were worn and needed to be replaced before it would hold an alignment...not a safety issue, just that it would not hold an alignment as it is. I also need to replace a couple of sagging leaf springs.

Prior to each of the last two trips we took (about 600 miles round trip each) I pumped the grease zerks on the front end, especially the king pins, full of a high quality grease and was amazed at how good the coach drove after that. I didn't have to fight it to stay in the lane.

Perhaps you have some small amount of play in your front end that, as has been pointed out already.. on something the size of a motorhome small actions are magnified to make it feel like it's wandering all over the road. Just another offer of an opinion....

[Bikeboy57]

That should be enough toe, that's a little over 1/8.

The situation where the trailer makes it worse sounds like the rear end is wagging side to side. The owners with the links to stabilizing the rear are worth reading.

[Slojoe72]

.08
.09
Positive toe after alignment

[Bikeboy57]

What is the toe in reading? Too little toe will make the coach wander just as you describe. Too little caster will reduce the coaches tendency to straighten out when turned, resulting in wandering. Too much play in the steering box will result in sloppiness when steering on dead center. Too tight of a steering box results in the steering sticking when making small corrections on center which makes the coach wander in the lane.

The easiest thing to change is the toe in. If you are towing a race car then you should know how to measure and set the toe.

[YC_1]

If you will click on my link it will tell you about the watts link, the cross bars, the steering gear box change, and everything you ever wanted to know about making the 8 bag roadmaster a real proper handling rv.

[RFCN2]

Only 35,000 miles on a 17 year old coach means it likely has had this problem since new. Coaches that are fun to drive usually rack up the miles. But that does not solve your problem. A motorhome I bought about ten years ago rambled down the highway left then right then left and so on and so on. I spent four years and many many many dollars and hours of time trying to improve it. It finally got to the point that it drove OK, but not great. So I sold it and made SURE that the next coach handled well before I bought it.

On your current coach check the simple stuff

1. Alignment - but looks like you have already done that.
2. Weigh all four corners to make sure weight distribution is OK.
3. Increase your tire pressure to what the manufacturer recommended.
4. Try and resist the urge to oversteer.
5. Class A motorhomes are huge boxes going down the road. The steering is greatly affected by the wind. In my experience they are never going to drive down the road as well as an aerodynamic car.

If this does not bring the coach up to what you want, sell it. And then buy one after you have test driven it for a stretch down a freeway that is straight and it does not wander. I also bought the RVCG listings. I did not seriously consider any coach that did not get an excellent rating from them on handling.

Next time remember that coaches with low miles that are used it may mean that they are not fun to drive and so no one drove them much. Coaches with average or above miles very likely were lots of fun to drive and therefore people drove them a lot.

My current coach is a hoot to drive. But even that said when the wind is blowing hard it is less fun.

[et2]

What model is your motorhome? Not just make? What is the hitch allowance? What is the tow allowance? What does the coach weigh loaded? What is it's unloaded weight? What is the GVWR? What is the GCWR? What are your GAWR? Where does you coach fall within these? Do you have the owners manual. Do you know the weight specifics? Axle weight specifications? Have you weighed your coach? What does your trailer weigh loaded? Are your tires aired to the loaded weight? If your airing them properly your tires would have different pressure traveling with the trailer vs without. Especially without a weight distribution hitch.

Until you now these things it's just a c rap shoot.

[lanerd]

Slojoe72 wrote:
It is my first

Did you read my reply above???

Ron

[DSDP_Don]

"Slojoe72"........I had an 05 Diplomat and added Koni shocks, front and rear sway bars, adjusted the ride height and made sure the tire pressure worked for my coach. It handled well and tracked fairly well.

Shortly after I sold it, a couple of guys on the Monaco Forum developed some x-bars and watts links for the Roadmaster chassis. If you look under your coach, the Roadmaster suspension, front and rear is a big floating "H". One of the guys from the other forum, took a 10' piece of square tubing, stuck it in his hitch receiver and found the entire rear end of the Roadmaster chassis could be moved side to side by moving the bar side to side. They developed the watts link and x-bars to lock down primarily the rear end and the front end.

Go here and do a search for the components. They're pretty reasonably priced. Forum

[YC_1]

YC 1 wrote:
Read these threads

Did you check out these threads. They are about Monaco coaches and it is all about your problem.

If is not an issue with your driving. It is an issue with the chassis design.

For an example: Grab your steering wheel with the engine off and turn it right and left. How far can you move it before it tightens up?

[Ivylog]

Since the trailer handled OK behind your PU dually and the MH does it with and without the trailer, it's the MH or as lanerd implied... possibly the driver of the MH. Monaco's RR8R chassis is noted for their good handling, even with more than 10K behind it plus you had it aligned without a change. Coming from a PU and assuming your the driver of the race car, it's natural and easy to oversteer something this long... even after a year. With practice and no wind it's amazing how little steering input it takes to keep it straight, but you have to give a small input three times as long to take affect. Looking further out will help, but once you start chasing it, especially with a long trailer on the back the harder it gets to stop oversteering... NO offence as even after 12 years on a really windy day I'll sometimes have to remind myself to stop fighting it and give things a little more time.

[Slojoe72]

It is my first

[Ivylog]

Is this your first large mh????? I would say the caster is close enough.

[Slojoe72]

Soooooo. I found my alignment sheet that I got done last year.
In referance to caster (mentioned earlier) caster range supposed to 5.0-7.0. Mine are in the red with 4.8, and 4.7. I remember the guy mentioning to me it would need some type of shim kit to get it in the range. He said it was close, and even on both sides and thought it would be good. Should I get them to do the shim kit and shoot for closer to the high end at 7 degrees.??

Thanks