Wallowing Beast

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 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 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.

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.

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!

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.

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.

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.

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.

We had an older Class C, about the size of yours, on a Ford E350. Rebuilding the front sway bar with new end links and end bushings, made a big difference in the coach's stability. I replaced rubber with polyurethane.

I helped an OP here on RV.net with installing a Hellwig rear sway bar on a Chevy chassis and he noted a big difference. Even more importantly, his WIFE noted a big difference...

EDIT: From the pic, it doesn't look like the rig is riding low in the rear, but it's certainly possible that the rear leaf springs have gone soft. An RV isn't like a box truck. RV is pretty much fully loaded all the time. That's a lot of weight standing on the springs, 24x7, the whole life of the RV.