Swaying and rocking

[Davidkallan989]

New to motorhomes, but experienced campers, towed and camped with TTs for years.

Our Sightseer seems to have a little “lean” to the right and IMHO seems to sway and rock quite a bit.

FYI - My brother in-law owns a newer model Sightseer and the gap from his rear tires to the whelk well is 2-3” less than our 2012 Sightseer model 35J.

Thoughts

 

[Mark_K5LXP]

Your chassis will have a spec for the distance of the frame to a point of the suspension for correct clearance. Wheel well distance isn't hard and fast because the body and tires can be different for disparate models.

Mark B.
Albuquerque, NM

 

[Onyrlef]

New to motorhomes, but experienced campers, towed and camped with TTs for years.

Our Sightseer seems to have a little “lean” to the right and IMHO seems to sway and rock quite a bit.

FYI - My brother in-law owns a newer model Sightseer and the gap from his rear tires to the whelk well is 2-3” less than our 2012 Sightseer model 35J.

Thoughts

My MH was heavy on one side and developed a list to that side. I did two things. Added a leaf on that side ( you can also add a thicker block under the leaf springs on that side) and installed air bags. The unusual sway and rocking could indicate the springs have lost arch or rocker ( the opposite of camber).

 

[Ray-IN]

Sway and rock is an indicator of worn-out shocks. MIleage and AGE slowly destroy shocks. The shocks on my MH were bad at 23,000 miles and 13 years old. I replaced them with the same brand and model. Immediately the ride was smooth, even, and steering was easier as a result.

 

[Kirk]

The first thing that I'd do is to get weights for not only each axle but also each side as it is probably heavy on the low side and may well be over the weight limits for the axles or the individual tires. I am assuming that you bought it used and don't know if it was always that way? I would also agree with Ray that you probably need to replace the shocks as rocking usually means that they are bad but that will not correct the side to side issue. Gas chassis motorhomes tend to be near the max GVWR most of the time and weight distribution is often made worse when the owner loads his stuff into it. With a 12 year old motorhome it could also be experiencing tail sag issues, especially if the previous owners ran it overloaded. Because the body of most gas chassis motorhomes is extended well beyond the trailing end of the factory frame rails, in time the rear springs begin to sag and the heavy side will sag most. There are a lot of things that could be done to improve things but you first need to know the weight and weight distribution.

 

[Onyrlef]

Cat Scales ( policy) aren’t going to allow side weighing so that could be hard to accomplish. Ordinarily RV’s, like Manufactured Homes ( double and triple wide sections especially) have what is termed “the wet side”. For example when you see two sections of a Manuf. Home going down the highway the “wet” or heavy side will have additional axles. Unfortunately in a MH the heavy side and the lighter side ( if that’s the case) are supported identically. Over time the additional weight may cause the springs on that side to weaken. Especially if it’s being compounded by fresh water, black and gray water, fuel and misc. weight distribution. As Kirk says, if you’re in a gas chassis it doesn’t take much to be overweight. New shocks won’t fix a listing issue, but they could address the swaying and rocking.

 

[dktool]

My current '92 Flair had a 3/4" spacer block on the left leaf spring pack, I guess they thought it needed it due to the waste tanks being in that corner.
All it did was make that corner high and contributed to possible worse handling, I removed it and it sits level now and does drive better.

 

[Gary RV_Wizard]

Your situation is quite common on motorhomes that have a leaf spring suspension. One side of a motorhome is often heavier than the other and leaf springs are not self-adjusting like the air suspension of a diesel pusher. You may be able top have some effect by relocating heavier objects in the storage bays, but more likely you will need a chassis shop to manually adjust (shim) the suspension. Or maybe even add a leaf to the springs in extreme cases. I suggest getting "corner weights", i.e. weighing the coach side-to-side and front-to-back to calculate the load on each wheel "corner". Some scales can do individual wheel corners directly.

Sway & rock is also a common problem. Moreso with leaf springs than air, but present in both. Higher end models with more capable chassis suffer less from this, but it's a matter of degree. No motorhome will be the equal of a modern car or SUV.

Shocks dampen the speed of the suspension rebound but don't actually do much to stop sway or rock. The coach is top heavy and literally leans on turns and even lane changes. Stiffer shocks can reduce the effect at the cost of a harsher ride on bumpy roads. There are suspension upgrades that can help, e.g. Sumo Springs, the Ford chassis "Cheap Handling Fix" (more about this later), heavier duty anti-sway bars, etc.
Henderson's Line-Up, the gurus of motorhome handlng & suspension, recommend against the CHF. See Cheap Handling Fix

 

[Onyrlef]

Cat Scale

 

[Professor David]

I haven't done this yet but would like to soon. Simple explanation on how to weigh each corner on a CAT scale.

 

[Professor David]

the Ford chassis "Cheap Handling Fix" (more about this later), heavier duty anti-sway bars, etc.
Henderson's Line-Up, the gurus of motorhome handlng & suspension, recommend against the CHF. See Cheap Handling Fix

I went with just beefing up the front anti-sway bar rather than the "CHF". Easy switch out but did cost me $539 for the new beefed up part.

Amazon.com

 

[Onyrlef]

I haven't done this yet but would like to soon. Simple explanation on how to weigh each corner on a CAT scale.

That’s brilliant, in order to weigh one side only you need one side only on the scale. That’s fine but it’s against Cat Scale Policy. Besides after you’ve initially weighed both axles and if you can do math all you’d need is the weight of either the driver or passenger side.

 

[Ray-IN]

I haven't done this yet but would like to soon. Simple explanation on how to weigh each corner on a CAT scale.

He didn't mention the RV must sit level during the one-side weigh, otherwise the results are not accurate.

 

[Gary RV_Wizard]

He didn't mention the RV must sit level during the one-side weigh, otherwise the results are not accurate.

True, but maybe not of great importance for this purpose. The low side will be a bit heavier than when level, but you must use the heavier axle-end weight for both ends anyway, so at worst you may be inflating a bit higher than what a level-scale would have shown. That's probably a good thing.

 

[Ray-IN]

True, but maybe not of great importance for this purpose. The low side will be a bit heavier than when level, but you must use the heavier axle-end weight for both ends anyway, so at worst you may be inflating a bit higher than what a level-scale would have shown. That's probably a good thing.

Well, yes, except if the high side is the scales.