Improving harsh ride?

[rbreak]

Hello all,
I recently bought a 2008 Winnebago Access 29t class C with the Ford E-450 chassis. The suspension appears to be all stock with only 21k miles on the coach. It handles acceptably concerning wind or semis passing by, turning is ok and it’s not wandering all over the road or driving poorly in those areas. Where it’s not so good is bumpy roads, rail road crossings, expansion joints, etc. It is jarring, slamming and extremely harsh in that area. I do understand that this is a 12K+ lb big truck with a heavy duty suspension, I owned a Dodge Ram 2500 4x4 quad cab diesel for almost 9 years so I get that heavy duty trucks are not going to ride soft, and I’m not expecting it to ride like an suv or anything, I was just wondering if there is any proven improvement to the slamming and jarring over the bumps. It sounds like it’s going to break something on some of the bumpier roads, I don’t know if it’s bottoming out or the suspension is so stiff in the back that its hardly even absorbing anything. I have done some searching and reading on here and read about the Koni FSD or Bilstien shocks, but I was wondering if some of the other suspension options like sumo springs, timbrens, air bags, etc. help any with the slamming. I did a lot of searching and could not find much info on those items concerning smoothing out the ride. My rig already has fairly thick front and rear sway bars, and I’m not sure how putting in a bigger, stiffer sway bar would help on the bumps, so I hadn’t really considered that. I have also read up on the tire pressure for actual weight and will experiment with that as soon as I can get the coach weighed on a cat scale.

Thanks in advance for any help, ideas, experience or information. If there really isn’t a reasonable way to improve the ride, that is ok too but I don’t want to be miss it if there is a readily available improvement.

(On a separate note, I had to post this using Woodall’s forum, could not get picky rvnet to accept anything)

[samven1]

I have the Firestone airbags on my E3500 Chevy chassis. I measured the bumper height before loading and then adjust the airbags after loaded to bring it back to the measured height. I dont think it gives me any softer a ride but it stops the tail from dragging in swales and helps stability in turns.
I think soft ride is a very relative term when applied to a 1 or 1.5 ton truck on a rough road loaded with breakable items. I just wish people would not get so upset with me when I slow down on those sections.

[oldusedbear]

Have a 2001 E450 with a 23 foot Coachhouse. Terrible ride originally. First - - replaced ENTIRE rear leaf spring suspension with a Reyco Granning air suspension (real thing - - not just little air bags like Firestone etc). Then bought Koni shocks - - before the FSD was available for this chassis. Still rough so sent shocks back to Koni for revalving. Still not happy but finally Koni made FSD for this chassis so ordered and installed them. Quite decent ride and handling now. Info in greater detail if you email me at rhaag11@charter.net

[tpi]

I have small light 24 on E450 and looking at the way it sits, I don't think I want to change anything. It certainly does not ride high in the rear. Ride is not extremely rough. It's not that great on poorly paved surfaces, but tolerable. There are some terrible roads which would give a poor ride on almost anything. On smoother roads (majority) it is fine. For me the handling was a far bigger concern than the ride.

If I was to address the ride, I'd probably start with the bushings in the rear. Something to reduce transmitted harshness. Also rolling around with 20 PSI needless extra air pressure in the front tires degrades ride. But I think the front suspension is better isolated from a ride standpoint than the rear.

[ron_dittmer]

Healeyman wrote:
Rob,

Our first RV was a 22' Four Winds on a Chevy 3500 (1 Ton) truck chassis.

When we first got it, the ride was like yours, TERRIBLE!!! We actually had silverware bounce out of the drawer and broke glassware in the cabinet.

One day, I crawled underneath and looked at the spring stack on the rear axle.

The 13 leaves of the spring stack were absolutely FLAT. There was NO arch in the springs. When striking a bump, the rear axle could NOT move UP to absorb the blow.

The air in the rear tires was the ONLY suspension that there was. The axle housing was still 2 inches from the rubber bump stops (POOR design).

I ordered a set of 5,000 lb. capacity Air-Lift air bags (about $200) and installed them myself in a couple of hours. I didn't even have to jack up the body to get them installed. I ran the air inlet tubes to a storage bay.

When I added 55 pounds of air (about 1/2 full) the body actually rose up 1-1/2 inches. Now I had 1-1/2 inches of Tire, spring, and air bag travel.

The bags made it an ENTIRELY new RV. It was wonderful!

Later on, I added Bilstein shocks to the FRONT in order to stabilize and eliminate the "porpoising" on that end.

In the end, the ride was FANTACTIC!!! The ride was almost as good as that of my 3-seat GMC Suburban.

When we upgaded to a 28 ft. Coachmen Freelander, it came with Air-Lift air bags installed at the factory. I have never had to add air to them to use them.

I suggest that you or a shop-guy look at the rear spring stack to see whether or not you have any, or adequate, rear axle UP-travel.

Tim

Healeyman Tim,

Funny, I have the opposite story with air bags. The more air I put into them, the stiffer the suspension became. The less air, the softer the ride, but the worse the handling. Maybe your story is the opposite of mine because of the way your leaf springs were positioned.

I considered Sulastic Shackles for our E350 because we too could benefit from a softer ride. (Everyone could, right?) They are made for an E350/E450 motor home. I liked their bolt-on simplistic approach. I just never could justify the ~$400 cost given our ride is not all that rough.

I have always wondered if a small motor home built on an E450 which suffers from an extremely rough ride, could be taken to a specialty shop and have a leaf spring or two removed to bring the chassis load rating closer to the actual load to get a softer ride.

[wearenh]

klutchdust wrote:
I don't know how to do links but this is what I did .

> Koni FSD shocks installed (updates)

do a search on this forum and see if it could help you, it sure did change my ride dramatically...

WOW ... just back from first long trip since installing the Koni FSDs ... DRAMATIC favorable
improvement in both harshness over bumps, and in overall responsiveness ... do it!



.

[ADOR]

Same thing happened to me. I have my Class C for 3 months now. When we did the PDI, NO ONE told me about the air bags. I only noticed them when I had my metal valves installed last Saturday. I looked around the inside bottom storage units and found one air valve on each side. One had 5PSI, the other ZERO. I inflated both to 70 PSI as indicated on the air bag manufacturer's manual. I have not taken it out for a ride yet.

stripit wrote:
My unit has a set of air bags from the factory that I didn't know were there. I purchased it used and also thought it rode roughish over some roads. I found the air valves one day in the cabinet on the drivers side in front of the wheels stuck in a corner that was hard to see. I put a air gauge on them and found zero reading. Put 40 lbs of air in and went for a ride, what a difference. Added another 5 lbs and drove it again, even better. So since your unit has no air i would suggest a set of air shocks to soften the ride.

[rbreak]

My coach definitely does not have air bags. When I was looking to buy, it seemed pretty random if they came on a coach from the factory or not. The nearest frame shop is a couple of hours away from me, if I can't improve it with the normal air bag and shocks approach, I may look into that.
Thanks again for the responses.

[rockhillmanor]

j-d wrote:
I think it's possible the E450 uses rear springs that are arched opposite of what we usually think. Somebody here may be able to explain that. I mention it now because I am not sure that an E450 spring that is not bowed DOWN has collapsed. Till you have an understanding, don't replace springs on their appearance alone.

X2
That's why I take it to a frame shop they have the trained eyes for that AND they've got these incredible mathematical calculations they work with. When I looked at the leafs they looked fine but they were not to someone who knows that stuff.

They started asking me all what I wanted and spewing all these mathematical figures related to metal at me! I told them to do what they thought was best. When all was said and done the ride as I mention was just unbelievable and as an added bonus it lifted that long rear end up too!

[rockhillmanor]

.double post

[ol__yeller]

I have a 2008 Aspect 26A and it has airbags in the rear. Are you sure yours doesn't have them? My ride is excellent for a heavy rig but it is a big heavy rig and won't ride like your car. I run 80# in the rear bags.

[rbreak]

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/20572936/print/true.cfm

Interesting thread with info on the inverse leaf springs, doesn't really clear anything up, but sounds like it "might" be designed that way from ford.

[rbreak]

From what I have read there is an air pressure range with the air bags that helps the ride but you have to experiment with pressure to find what helps each particular coach. Too much pressure will give a harsh ride and too little doesn't really change anything, but the right amount improves the ride some (again, going from what others have posted, I have no experience myself).

[Magiccat1]

I put air lifts on my 24' class C to raise the rear end so my hitch would clear my drive way.
Did not notice much in the way of improving the harsh ride but maybe I am looking at this wrong. Should I have a higher pressure in the lifts for a less bumpy ride or less? I thought less would help but what do I know. As usual I am confused. Talked to the "tech" people at the air lift company but they were vague. Will be crawling under to look at how the leafs look at stand still......Thanks for any insight.

[rbreak]

Thanks again for all the responses. J-d, I also had read somewhere (can't find it now) that the E-450 leaf pack was an inverse arch design. Seems like a strange concept, I will continue looking for more info on it.