Wallowing Beast

[BOBS66440]

My new to me RV runs and drives well, but definitely feels wallowy, overloaded and top-heavy. It's somewhat unnerving to drive, though once on the open road it seems fine. I have never driven one of these before and my buddy (who has) says generally, that's just the way they are. I used to have a CDL and have driven big trucks before but this is very mushy compared. The shocks and springs are good I think. It has a front anti sway bar and the bushings are good but it does not have a rear anti sway bar. I have seen aftermarket rear bars and am wondering if this is an improvement that will make a difference? Thanks!

[BOBS66440]

j-d wrote:


OP, Your word "Wallowing" continues to nag me. Unless your other car is a Porsche, you shouldn't be using "wallow" as a comparative to other vehicles' handling when you talk about a relatively small RV. I envision EXTREME sway, and it's hard to think there isn't something badly worn or damaged in the OEM springs or their shackles, etc. But especially on a Chevy chassis, that seems to handle a little better than a comparable Ford, "wallow" just doesn't fit, at least for me. By all means, the Hellwig sway bar will help. I hope it alleviates your defined wallow. If not, air bags might work, and speaking of Hellwig, a "helper" spring that kicks in when one side it goes to be the down side the helper on the up side isn't stiffening it. My guess... If it wallows as bad as the word Wallow implies, I think there's spring work ahead... And I hope not, just a couple mods will help you.

Well, actually my other car is a very stiff C5 Corvette and the RVs primary purpose is to tow my Formula Vee race car to SCCA road racing events, so I guess I'm somewhat spoiled regarding handling. But I also used to drive a 55,000lb plow truck and I don't remember it being like this. Of course that truck had extremely heavy duty suspension for carrying super heavy loads so it's really not Apples to Apples.
This RV was actually very good on the highway when I drove it home from purchasing it, it was actually a very windy day and didn't seem to be affected much at all. The problem comes when turning, it just seems very top-heavy as if it was grossly overloaded. I spoke to my friend who used to own a Class A RV and he said that basically that's just the way they handle for the most part. Having some knowledge of suspension and handling, I know that an anti-sway bar is what controls lean as well as the springs and to an extent the shocks. Since I have installed the sway bar I will see how it is and go from there I guess. I can also definitely see how tire pressure would effect that. I will inflate the tires to the proper setting also. That should definitely help. If it still isn't right I guess I will move on to the next step. I will also look at replacing the front bushings with urethane as OFDPOS mentioned. Thank you all for your help I appreciate it.

[OFDPOS]

My $.02 ... I'm the OP that J-D lent a hand in installing a Helwig rear sway bar. That made a big difference.

I had replaced the front worn old rubber bushings on the front stock sway bar with polyurethane bushings.
Next up replaced shocks front and rear with Bilsteins , then since the tires were over 6 years old I replaced them with Michelens .
At the time I only had the tire shop put metal valve stems on all 6 wheels.
Regretted that and ordered a Tire Man valve stem kit.
Tire shop was nice enough to switch out the valve stems at no charge.

Last was with the aid of J-D We put the rear Helwig sway bar on .

Over all night and day from when I first bought it and drove it the 75 miles home with a 20-30 mph cross wind...

So if you plan on getting tires, get one of the valve stem kits mentioned so they can be installed when the tires are replaced.

Then replace the shocks , I think Shockwarehouse.com is where a few got the shocks from, the local Autozone matched the above price plus I when I ordered them I got a $25 dollar card to use on future purchase from Autozone.

Depending on where you get the tires ? For a few extra $$ have them install the front shocks, much easier with the front wheels off 😉 The rears are easy a DIY project.

You already did the rear sway bar , so now replace the front sway bar bushings with the polyurethane bushings.

If by chance you do get an alignment check , have the MH loaded up like your going on a trip , FW tank full, propane tank full, added cargo , you get the idea.

Good luck and happy RVing ...

[Olddud]

wbwood wrote:
You can't drive them like you drive a buick...lol

More like driving a "brick".

[wbwood]

Consider how you are driving also...these are definitely top heavy. You can't drive them like you drive a buick...lol

[M___J]

I bought a Winnie 24 footer on a Ford 450 chassis so this may not be relevant. It had a original Firestone tires that were 6 years old and starting to check. I replace them with new 6 Michelin tires and and new Monroe shocks. Man, what a difference. It handled so much better that it was like a different motorhome.

[j-d]

Hank, Think carefully about a single INFLATOR. If you want to inflate both bags with side-by side air fittings, that's a very good thing. But a common fitting, then a Tee to allow inflation of both bags, isn't a good strategy if you want then to help you with sway. When it goes to "wallow" you want the bag on the down side to hang tough, not transfer some of its pressure to the bag on the up side.

OP, Your word "Wallowing" continues to nag me. Unless your other car is a Porsche, you shouldn't be using "wallow" as a comparative to other vehicles' handling when you talk about a relatively small RV. I envision EXTREME sway, and it's hard to think there isn't something badly worn or damaged in the OEM springs or their shackles, etc. But especially on a Chevy chassis, that seems to handle a little better than a comparable Ford, "wallow" just doesn't fit, at least for me. By all means, the Hellwig sway bar will help. I hope it alleviates your defined wallow. If not, air bags might work, and speaking of Hellwig, a "helper" spring that kicks in when one side it goes to be the down side the helper on the up side isn't stiffening it. My guess... If it wallows as bad as the word Wallow implies, I think there's spring work ahead... And I hope not, just a couple mods will help you.

OH! I think it came up earlier in this thread, but don't underestimate your FRONT sway bar. If it already has one, spend a few dollars on hard plastic bushings for it. A Hellwig front bar would help even more, but getting the best you can out of the existing one might be enough.

[Harvard]

Hank85713 wrote:
.... Mine is an E450 BTW
13000lbs on scale.

Ford E series are known to "wander" and have "loose steering" at highway speeds if they have too little + caster. Ford ships the E series with about +3 degrees which is OK for city driving but you want to have at least +5 for highway driving.

[Hank85713]

I havent been following this discussion, but let me add my 1/2cent. We bought a 28 ft winnebago B+ and first trip it was as you decribed. Wallowed and wandered. The rig had air bags but I could not get them to be inglated as I didn't have the right type chuck, tire store could not reach inner tires to inflate! At any rate I finally got the tires inflated to recommended but still wallowed, got air to air bags and it DEFINITELY made a difference. Played with setting and finally got ride of most of it. just need to make a 1 point connector as the air bag fill point is is an awkward place and are individual so kinda hard to equalize. Give the air bags a thought. Mine is an E450 BTW
13000lbs on scale.

[Cobra21]

I have a short wheel base Chev. like yours and it can be a challenge on windy days. Plus 20 mph and gusty is bad. My door jamb states 55 psi, I may try 60 this spring after reading these posts. My water tank is at the rear of the rv, I have driven it empty and full and have not noticed any difference in handling. I don't go out in a wind storm, and do use 2 hands on the wheel. It does get easier with more driving experience...but my next rig will have a longer wheel base.

Enjoy, Brian

[j-d]

Best I can tell, the only harm 80 PSI rear "might" do in a Class C is worsen the ride, and probably only slightly. Especially since the rear axle ride in a Class C (at least a Ford) is already awful.

65 PSI is max for a Ford Class C through 2007 chassis year. That adds up to their 4600 front axle capacity (GAWR-F). In a 2008 or newer, the 5000 axle calls for 80, again if fully loaded. I installed a 5000 axle (from a 2012) in ours and am at 65 for its 4600 scale weight. Tire shop inflated new fronts to 80 and it was nearly uncontrollable under very adverse conditions. We were going 65 down a concrete-decked bridge (in my experience asphalt tracks better) in a crosswind. I actually stopped on the side of the road to lower the pressure.

[pnichols]

I don't use 80 lbs. pressure in the rear duals of our Class C because it's mentioned on their sidewalls as maximum pressure.

I use 80 lbs. of pressure because ... in an effort to accomplish other goals ... that's the highest pressure that can be used without stressing the Load Range E tires beyond their published engineered limit. Those other goals are:

- Make the sidewalls as rigid as possible to minimize wallowing in the rear of the Class C.

- Make the sidewalls as rigid as possible to help minimize heat buildup from flexing of the sidewalls so as to maximize tire material life.

- Ensure that the inward-facing sidewalls of the rear duals never bump against each other during normal up and down bouncing when traveling.

- Ensure maximum spacing at all times between the inward-facing sidewalls of the rear duals for least restrictive air flow to help minimize heat buildup in sidewalls so as to maximize tire material life.

In many years of using 80 lbs. pressure in the rear duals, I've never noticed any wear in the center of the tread over wear along the borders of the tread. I have noticed this in lighter weight vehicles I've owned, but never on the Class C's M&S Michelin tires.

FWIW, I use 65 lbs. of pressure in the front tires and can roll along the highway steering by comfortably using only one hand on the wheel (when safe to do so).

[j-d]

CharlesinGA wrote:
I believe the recommended pressure is printed on a placard inside the driver's door on most vehicles. Of course as you point out, circumstances dictate...

Problem with that is, in most cases the RV manufacturer will simply repeat the Chassis manufacturer's recommendation. And that recommendation is for the maximum loading the chassis manufacturer specifies. If our specific RV, loaded and ready for the road, people, food, clothing, supplies and all, is less than that max weight, then our tires are overinflated for our actual load.

One tire manufacturer's chart (such as Michelin's that's so easy to find) will work for other brands, so long as the tire specs match.

On any vehicle, there's an ideal tire pressure and negative consequences in ride, handling, wear, and possibly failure (those Ford Explorer blowouts!) for pressures that are grossly wrong. As a Ford E-Series owner, I'm acutely aware that FRONT tire pressure has a huge effect on steering stability. There's a narrow spread either side of the charted rating, seems to be only about 5 PSI, where stability is best.

Other chassis brands don't seem to be as touchy as the Twin-I-Beam Fords, but there's still an ideal pressure, and the number on the sidewall (repeated by vehicle builder for liability purposes) usually isn't it.

[BOBS66440]

CharlesinGA wrote:

pnichols wrote:
You need to:

2. Run your rear tires at the Load E maximum of 80 lbs..

Common mis conception is to run tires at sidewall max inflation pressure. This creates a harsh ride and poor tire wear. There is a magic number for every circumstance based on weight the tires are carrying, and it isn't the max. On my 10,200 lb Max Gross View with 225/75R16 E rated tires, the number is about 62 lbs.

Scroll down to page 21 of the PDF linked to for LT tire inflation ratings for 16 inch wheels, both single and dual. You have to know the load on the axle to read the charts, and this is for Michelin tires, but I suspect that other brands will not vary much from this.

http://www.michelintruck.com/assets/pdf/Truck_Tire_Data_Book_Jan2007.pdf

Charles

I believe the recommended pressure is printed on a placard inside the driver's door on most vehicles. Of course as you point out, circumstances dictate...

[sullivanclan]

I'm far from an expert in this area, but after a similar feeling when I first purchased ours used:

1. Check air pressure, then how you are loading. Try it both empty/dry and loaded for differences.
2. Go to a service center that deals with RV's and trucks. I learned a lot when they did a drive with me, as they have driven dozens and can compare the feel to their other experiences.
3. Let them do a good check of everything underneath. Make a few repairs, one or two at a time. Test drive again.
4. Only consider more costly upgrades after you know things are working as they should first.

Wish you the best....