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]

Regarding alignment, Fortunately the tracking is very good on it. It doesn't seem to wander at all and the steering is very tight. The tires also have a fair amount of miles on them and show no signs of uneven wear. The problem is really just the top heavy, tippy feeling of it. In any case I'm going to bring it to my mechanic and have him go over the whole thing.

[Snowman9000]

I don't know how you'd feel about $600+ worth of shocks, but the Koni FSD shocks are in a league of their own for RVs IMO. You might start with the rears to save money. They don't just dampen. They have variable valving according the size of the movement. So they do a good job of stopping wallowing. They are made for Chevy Express van series. I have them on my 4500.

[Harvard]

If you are going to an alignment shop pay particular to the caster angle. Yes, I know this is a chevy chassis, AND we have no alignment experiences with chevs. Maybe the caster could be a handling issue maybe not. If the caster is around +3 degrees it may be a problem, +5 degrees of caster is better. Too little caster can manifest itself as "loose steering" and "wandering" at highway speeds no matter if it is on a Ford or on a Chevy.

[enblethen]

I would have a truck type alignment shop look at the front end before spending money on sway bar.
Don't forget about weighing the rig. This will or should tell you how much air in tires rather then guessing.

[BOBS66440]

Yes after all the great advice I think I'll get the rear sway bar and inflate the tires and go from there. Thank you everyone!

[ron_dittmer]

Bob,

You are on the right track with your top two.

Most critical is tire pressure to assure you don't get a blow-out. Based on your dry weight spec of 9400 pounds which is the same as our rig, I would start with 65 psi in all 4 tires as that is what I run with. Maybe even start with 70 psi. If it's too much, you won't do any harm given they are "E" rated tires with an 80 psi max rating. 55 psi seems alarmingly low, at risk of blow-outs and significant handling troubles.

Adding a heavy duty rear stabilizer will do wonders. Don't yield on that addition. A Helwig will be more affordable than a Roadmaster.

Everything else can be done after a thorough evaluation of the top two. If your rig could still use extra help, consider heavy duty RV shocks and a heavy duty front stabilizer bar.

Front & rear heavy duty Helwig stabilizer bars are affordable and are DIY friendly....especially the front bar. Heavy duty shocks can be pricey and not so DIY friendly, primarily due to rusty mounting bolts.

If it were me, I would get the tires up to 65-70 psi and install both front & rear HD Helwig bars and HD shocks. Then re-evaluate afterward. You won't be throwing away any money with that investment of around $750 in parts. Not only for driving comfort, your rig will be much safer to drive. It will remain more firmly planted on the road for improved braking power when on mountain and canyon byways. That is very cheap insurance that unlike all other insurance policies, it also pays in passenger comfort and reduced driver fatigue. It even pays while parked with less need for stabilizer jacks.

If towing anything, you might need to invest in a rear trak bar which eliminates the "Tail Wagging The Dog" condition. That condition is magnified with a long rear RV over-hang, rear of the rear axle along with a standard wheel base.

[BOBS66440]

DrewE wrote:

BOBS66440 wrote:

enblethen wrote:
Have you weighed the rig? Four corner plus front and back.
What tire pressure are you running?

I have not weighed it but the sticker says 9400lbs unloaded. The tires are load rated E. The fronts are at 55psi but I can't even see the rear valves to get a pressure gauge on them. There must be a way to measure the rears?

As with most (all?) duallies, the valve stems on the rear are in between the two wheels. I'm assuming you have daullies; it sure looks like it from the picture, though it's hard to tell with absolute certainty. If the chrome things are wheel simulators (i.e. hub caps), it may be easier to get at them with them removed. The ones I have, and others I've seen, are held on by two of the chrome lug nuts, the remaining ones being fakes. It's not hard to tell which are functioinal by tapping them gently with a wrench or something and listening to the sound.

You do of course need a dual head tire gauge to get at the valve stems of duallies. At least with the Ford wheels, the ones with a straight-on end chuck, rather than an angled one, seem to work better. The angled ones are somewhat more common, though.

It is a dually. I found an extension kit that may help.

[BOBS66440]

photobug wrote:
IMG_2724 by raindancephoto, on Flickr

you can see how heavy the rear sway bar is on mine. it's an e450 but you get the idea

I located one for my application. It seems logical to me that it should help. Thanks

[DrewE]

BOBS66440 wrote:

enblethen wrote:
Have you weighed the rig? Four corner plus front and back.
What tire pressure are you running?

I have not weighed it but the sticker says 9400lbs unloaded. The tires are load rated E. The fronts are at 55psi but I can't even see the rear valves to get a pressure gauge on them. There must be a way to measure the rears?

As with most (all?) duallies, the valve stems on the rear are in between the two wheels. I'm assuming you have daullies; it sure looks like it from the picture, though it's hard to tell with absolute certainty. If the chrome things are wheel simulators (i.e. hub caps), it may be easier to get at them with them removed. The ones I have, and others I've seen, are held on by two of the chrome lug nuts, the remaining ones being fakes. It's not hard to tell which are functioinal by tapping them gently with a wrench or something and listening to the sound.

You do of course need a dual head tire gauge to get at the valve stems of duallies. At least with the Ford wheels, the ones with a straight-on end chuck, rather than an angled one, seem to work better. The angled ones are somewhat more common, though.

[photobug]

IMG_2724 by raindancephoto, on Flickr

you can see how heavy the rear sway bar is on mine. it's an e450 but you get the idea

[donn0128]

Weight and the long rear overhang all can contribute to the problem. Adding a good anti sway bar might help along with really good shocks.

[enblethen]

Our old class C on the chev chassis needed upper control arm bushings. Didn't have that many miles but were worn out.

[IAMICHABOD]

BOBS66440 wrote:
The fronts are at 55psi but I can't even see the rear valves to get a pressure gauge on them. There must be a way to measure the rears?

A good addition and ease of checking your tire pressures are a set of extended valve stems. Tire Man or borg make them and you can check the air pressure in all tires quickly. The Tireman valve stems come with Flow Thru valve caps that makes the chore even easier and faster.

[mgirardo]

You should definitely weigh the motorhome. If you can get each corner, that's ideal. Not all scales weigh all four corners, you might have to settle for front axle and rear axle weights. Then check the tire manufacturer's specs on tire pressure.

You should also have the alignment checked and the ball joints checked. I noticed on our motorhome at the end of the year last year that the front was a little loose and figured it was time for an alignment. Turned out the ball joints were shot. Had them replaced, the front end aligned and the motorhome drives great now. No movement at all.

Our motorhome came from the factory with front and rear anti-sway bars. It amazes me that anything larger than a mini-suv comes from the factory without both front and rear anti-sway bars. A rear anti-sway bar will help with body roll and make it feel more stable.

-Michael

[BOBS66440]

enblethen wrote:
Have you weighed the rig? Four corner plus front and back.
What tire pressure are you running?

I have not weighed it but the sticker says 9400lbs unloaded. The tires are load rated E. The fronts are at 55psi but I can't even see the rear valves to get a pressure gauge on them. There must be a way to measure the rears?