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-   -   Rear Air bag or trac bar? (https://www.irv2.com/forums/f258/rear-air-bag-or-trac-bar-187249.html)

cjlove 12-23-2013 02:54 PM

Rear Air bag or trac bar?
 
I traded for a Class A; I had never driven a Class A before. It's an Itasca Sunstar 27N (28' 53F chassis, 18000 lbs.). Had an uncomfortable 2 days driving it home. Thought I was going to turn over a couple of times when a big truck passed and I crossed the outside line and hit uneven pavement. I've seen some info on forums and will be taking it to a Ford dealer to check caster, camber, toe, front suspension and steering alignment. The Ford service person on the phone said I may need rear air bags. I've seen on forums to start with front and rear trac bars, nothing about air bags. Service person at Camping World told me it doesn't have sway bars (don't know whether that's true). Camping World also increased tire pressure to 110 psi (which I suppose is the max printed on the tires); Label says 82 psi.
Sway bars, trac bars, air bags, steering stabilizer; which is best to start with for my control problem?

"007" 12-23-2013 04:03 PM

Welcome to irv2.
Tire pressures to high will not get a good foot print on road for traction.
You need to get coach weight, after you have it loaded with your stuff and follow the tire pressure tables for your tires.
A track bar in rear off the drive axel will improve the handling of passing trucks.
Select the bar for chassis you have here.

How one is mounted.

edgray 12-23-2013 04:21 PM

Quote:

Originally Posted by cjlove (Post 1855515)
I traded for a Class A; I had never driven a Class A before. It's an Itasca Sunstar 27N (28' 53F chassis, 18000 lbs.). Had an uncomfortable 2 days driving it home. Thought I was going to turn over a couple of times when a big truck passed and I crossed the outside line and hit uneven pavement. I've seen some info on forums and will be taking it to a Ford dealer to check caster, camber, toe, front suspension and steering alignment. The Ford service person on the phone said I may need rear air bags. I've seen on forums to start with front and rear trac bars, nothing about air bags. Service person at Camping World told me it doesn't have sway bars (don't know whether that's true). Camping World also increased tire pressure to 110 psi (which I suppose is the max printed on the tires); Label says 82 psi.
Sway bars, trac bars, air bags, steering stabilizer; which is best to start with for my control problem?

WELCOME to iRV2.com you've found the right place for all sorts of RV info. :thumb:
Like most new Class A drivers, you'll have a learning curve. But from what you posted you've already gotten some BAD advice and I believe much of your handling issues were CAUSED by CW setting the tires to their MAX inflation allowed rather than for the loaded weight you were driving. Since your coach is on the F53 Ford Chassis, I suggest you visit the Ford chassis forum here on iRV2 and read about the Cheap Handling Fix (CHF) many Ford owners swear by. IMO, air bags should be your LAST desperate attempt to control the beast.

Before spending ANY money, set the tires for the actual weight and see how much difference that makes. Good luck and safe travels!
Ed

cjlove 12-23-2013 05:20 PM

Thanks. I'll try the Ford Chassis Forum. I've never had an RV weighed, so will have to investigate doing that also.

ChasA 12-23-2013 05:27 PM

You don't say what year your rig is. But if it is a fairly recent model it has front and rear anti sway bars. I had a 2006 Sightseer on the 18000 lb F53 chassis. It suffered a lot of rear end push from passing trucks. I went to a Winnebago rally and there was a man named Chip Maddox giving a seminar on suspensions. He suggested that I start by adding a second, bigger anti sway bar on the rear. I had him install one right there at the rally. That fixed about 95% of the push. The name of the company is Rallies R Us. Chip knows his stuff. I think he only works on Winnebago products.

TXiceman 12-23-2013 05:36 PM

First thing to do is load it as for a typical travel and get the rig weighed. Adjust the tire pressure per the manufacturers load/pressure data. While loaded, get the front end alignment set properly.

Now take it for a drive and see how it does.

The air bags and the track bar serve two different purposes. The air bags basically support weight and give you a higher spring rate. The track bar, keeps the axle in position relative to the frame. Anti-roll bars limit the amount of side to side body roll.

MustangGT 12-24-2013 09:42 AM

These are some good suggestions to fix your handling problems. You DO have two problems: 1) keeping your house weight better distributed on the tires and 2) keeping the side-to-side house sway to a minimum while moving. I don't know of any product that will fix both. Up and down AND side to side.
My new 2 me 1997 34' Fleetwood already had air bags front and rear installed by a prior owner, so the "level the house" part was handled, but my RV also suffered from terrible side sway from semi's. I had to steer INTO the side of the trucks then back out juussssttt-riiiiiggght. I fixed that with a heavy steel trac-bar to fix the house to the rear axle. I designed it and a local welder made it. Install was easy. Check here>> Oemy's Web Site - DIY Trac Bar
LOVED that trac-bar on our trip to Colorado last year. No truck sway and we had STRONG southerly prairie winds going out on I40, and stronger northerly winds coming back on I70. It eliminated 90% of the sway problem.
Motorhomes should sport both features as standard equipment. Maybe now-adays they do. good luck

ghutch 12-24-2013 04:03 PM

From personal experience and having gone through what you are now, the handling can be fixed by doing the following:
1. Inflate tires to at least what the Winnebago label says. (probably 80lbs)
2. Preform the Cheep Handling Fix. (look on Ford forum on this site)
3. Invest in a rear track-bar. (This will practically eliminate the semi push.)
4. Maybe invest in a front steering stabilizer. (several mfr's. make them)
5. I'm 99% sure your chassis has front and rear sway bars already instaled from Ford.
Without going into geomety and physics, quick answer is do the things above. I did and now enjoy driving my coach. Read the 100's of handling post on the Ford chassis thread. Good luck.

vsheetz 12-24-2013 06:14 PM

Quote:

Originally Posted by ghutch (Post 1856746)
From personal experience and having gone through what you are now, the handling can be fixed by doing the following:
1. Inflate tires to at least what the Winnebago label says. (probably 80lbs)
2. Preform the Cheep Handling Fix. (look on Ford forum on this site)
3. Invest in a rear track-bar. (This will practically eliminate the semi push.)
4. Maybe invest in a front steering stabilizer. (several mfr's. make them)
5. I'm 99% sure your chassis has front and rear sway bars already instaled from Ford.
Without going into geomety and physics, quick answer is do the things above. I did and now enjoy driving my coach. Read the 100's of handling post on the Ford chassis thread. Good luck.

Need to know what year your chassis is to provide specifics. This outline is very similar to what I have done and the results with my 2001 F53 my coach.
Do ensure all the stock components are good and properly configured, and tire pressures are correct per weighing before doing any additions.

Finally Time 12-25-2013 06:42 PM

Winnebago Vista 27N
 
I have the '13 Winnebago version of your Itasca. Mine tracks very well down the highway and doesn't get pushed around too much by the big trucks passing. It handled pretty well off the lot, but I did have the front end aligned. Made some improvement. I keep the tire pressure at 82 lbs. I think if you have the alignment done and lower the tire pressure you won't have any problems. Try doing that before spending any more money on a trac bar, air bags, or steering stabilizer. I didn't find them necessary.

cjlove 12-26-2013 04:56 PM

Thanks, everyone. This is a 2013 Itasca Sunstar 27N on the F53 Chassis. I'll be taking it to a Ford dealer next week to check caster, camber, toe-in, front suspension, steering alignment, sway bar bushings and brackets, and maybe the cheap handling fix. I asked Ford Service about the CHF on the phone, and he had never heard of improving handling by moving the sway bars to the inside holes or by increasing the caster. Doesn't give me a lot of confidence (he's the one who suggested the air bag) but I don't know where else to take it.
I'll get it weighed with full gas tank (if I can get it to fill--another problem) and propane, but no water because it's winterized and also not fully packed for a trip. Camping World changed psi to 90 (label says 82 and tires say max 100). BTW, when I had the handling problems, the tires were underflated at around 75 psi from the La Mesa dealer.
I'm planning to post about a tow plate on my Jeep. Camping World thinks we may have had a Roadmaster tow bar previously, but the records I've found say we purchased a Tow-Me Combination from Safe Tow in 1997. Googling Safe Tow turned up nothing. Has anyone ever heard of Safe Tow?

Myssdragn 12-26-2013 06:31 PM

Check the max inflation on your tire sidewalls. I suspect that you have a higher load range tire than originally supplied with the chassis and that would explain the 110psi CW put in contrary to the plate inside the coach(one load range higher) and yes low tire inflation will contribute to the sway you experienced. I would definatly install or make a rear track bar as this will increase the stability and give a more car like feel to driving your coach. Make sure you do the cheap handling fix also at least on the front sway bar, this no cost improvement can be found by searching for cheap handling fix on the forums. If the above changes don't improve your coach then look into a front track bar but I believe your 2013 came from the factory with one.

cjlove 12-26-2013 08:49 PM

I'm so confused right now, not sure I know anything, but I think Itasca said it has front and rear anti-sway bars. I still haven't looked up the difference between sway bars and track bars, but I don't think it has a track bar. I printed the load/inflation info for my tires and don't understand that either. Double the lowest single PSI (80) is more than the front GAWR, and 4 times the dual is more than the rear GAWR. I want my little Class B+ back!

Myssdragn 12-27-2013 06:35 PM

1 Attachment(s)
I'm pretty sure that you have front and rear sway bars from the factory. These help to control body roll from side to side (rocking motion) and attach to both sides of the suspension. They twist when the body rolls side to side. The further they twist the more they resist the rolling motion. They twist in rubber mounts attached to the axle. Older Fords like mine (2003) are notorious for the rear sway bar mounting rubbers disintegrating. Track bars (Panard rods or bars) attach from the vehicle frame(stationary) to the suspension (moves up/down with the axle. In the attached picture you can see my rear track bar (painted black). This keeps the frame centered over the axle and prevents the large overhang behind the axle from allowing the spring stack to lean every time you turn the steering wheel or a passing trucks air pushes on the body. In the same picture at the bottom you can see the new blue sway bar bushings that I installed because the old ones had deteriorated. Your sway bar may pass over the top of the differential rather than under like mine but they have the same effect. The rear track bar(the black one) is easily the single best handling improvement I made to my coach after insuring correct tire pressure. Hope this helps.


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