Class c highway handling

[twinboat]

Originally Posted by Kjagger

So with the new sway bar, your wife is comfortable driving??

Yes, she says it's 100% better. Its still not like a car, but she is an ex school bus driver. If I ask she drives it. Thats about 1/4 the time.

[twinboat]

Originally Posted by ransil

I have a 2003 31' either I have settled and accepted how it drives or everyone else's really sucks to drive. The previous owners were truck driver's and had 2 or 3 extra leaves installed into the rear springs, maybe that is helping mine, everything else is still stock.

Extra spring leafs, air bags or sumo will lessen the roll, while stiffening up the suspension.

The sway bar will lessen the roll, with less stiffening of the ride.

As far as a track bar, stand near the rear of the MH and push it, at bumper height, and see how much it moves.
Next, push it at a point, 6 feet or more high, and see how easy it sways. A track bar won't fix that.

[discovery39s]

Been a few years back when we owned a C, moved to DP recently.
Our C handled horribly on the highway. Either trucks or windy days caused the ol white knuckle experience.

Here's what I did and it made a MAJOR difference. Added a front steering stabilizer and most importantly added rear air bags to get the weight back on the front end. The air bags ran at 75 lbs air pressure and provided night and day different. It set the caster and camber where it needs to be when the coach is level. it also transfers more weight on the front tires to assist in tracking.

Another advantage of the air bags is when it comes time to level the coach once on site. you can either leave air in or take out relative to the site conditions.

I installed both myself to save install cost and was pretty simple if your able and willing to do so. Parts were under 600 bucks and the best money I spent on the coach.

Good luck and in hopes this helps your issue.

[TXiceman]

We fought the roll or bump steer on a 31' Minnie Winnie. The Ford F450 chassis suspension is just not heavy enough to handle the weight of the big box on its back.

I put on Air Lift air springs front and back, next I put on Bilstein HD shocks. The last thing I did was to install heavy duty anti-roll bars with urethane bushings. I would attribute the handling improvements as:

Shocks 40%
Roll bars 40%
air strings 20%.

Prior to these changes, I loaded the Rv for normal travel and had it weighed. We were 13,950# on a 14,050# chassis. Since the fresh water tank was aft of the axles, we never carried more than 10 or 15 gallons of fresh water and traveled with the wast tanks empty.

While loaded, we had the front end aligned at an independent truck suspension shop. Ford does not align the chassis chassis properly. I had the alignment checked again after the modifications.

The RV drove easily and no more see-saw steering. The front tires wore evenly.

Good luck.

Ken

[hilgert]

I have a 2017 Sunseeker 2800QSF...a bit under 31 feet in length. Studied studied suspension improvements for over a year leading up to purchasing either a Class A gas or Class C gas. We went with the C as it can get into more of the smaller forest service type parks easier than an A.

I actually ordered front and rear Hellwig sway bars prior to picking up the new coach, as I knew from studying this forum, talking to many other owners at campgrounds (owned a trailer prior) and test driving many coaches that I'd want to address sway and ride quality from the start. I drove it a few times on some test runs before installing the sway bars, and after installing them the difference was WOW!!! The vehicle now corners like an SUV...no bad sway and in-control the whole time.

I also installed Knoi FSD shocks...twice as expensive as Other shocks, but the huge improvement in ride over road bumps/cracks makes them worth every penny. And, as suggested in prior posts, I had an alignment done to put in as much positive caster as possible. With the sway bars, the Koni shocks and the alignment the vehicle feels way more planted on the road than the many A and C gassers we test drove.

We just got back from a 2600 mile trip to Yellowstone, and in Kansas and Wyoming the winds were pretty bad (35mph+ in some places), but we just drove along sometimes at 75 mph, with myself and the wife switching driving every 4-5 hours or so when we got fuel. Had to sometimes hold the wheel turned into the high winds, but gusts and passing trucks were non-events (could feel them enough to know try were there, but never became an issue). I'll probably put in a TruCenter before the next big trip to help with the winds, but in 4 days of driving (2 up and 2 back from Texas, about 650 miles each day) we were never fatigued nor did we experience severe white-knuckle driving.

We were towing a Ford C-MAX 4-wheels-down the entire time.

Total cost for all the suspension improvements was $1400 including the alignment (I installed the Hellwigs myself, and paid the alignment shop $100 to install the Koni's because I was lazy). If anyone is in the fence, just do it...you will have no regrets. The alignment and the heavier front/rear sway bars are obvious; less obvious was the improvement from the Koni's, but I can say the before/after ride improvement makes the extra money for Koni FSDs worth it.

[Murf2u]

It's not just mechanical items either, technique is IMHO just as important.

The 'bow wave' and turbulence behind a large truck is very powerful, but it also dissipates very quickly.

Merely keeping as far away (in your lane of course) from the passing truck will make a HUGE difference in how much steering corrections will be required.

[George Schweikle]

I almost forgot about bump steer. For those of you who don't know, this is a condition where the steering angle changes when the body leans (Racers go to great lengths to eliminate this). I would have assumed that Ford had addressed this condition.

We had a 1983 27 ft. Winnebago Chieftain class A, P-30 chassis, that was so twitchy from bump steer that you could barely take your eyes off the road to tune the radio in any sort of side wind. Our 1995 Safari TREK had the same chassis, but was very stable, so I assumed that GM had made a change in front suspension geometry. I later saw an add for P-30 bump steer correction kit which traditionally changes the length or position of the tie rods to better match the A-arm geometry. The other way to address bump steer is to reduce the amount the body leans as Ken did.

A properly designed front suspension will not change steering angle if the chassis leans. Assuming that Ford class C chassis have bump steer problems due to body lean, my earlier suggestion of adding a track bar isn't necessarily the first corrective measure.

Originally Posted by TXiceman

We fought the roll or bump steer on a 31' Minnie Winnie. The Ford F450 chassis suspension is just not heavy enough to handle the weight of the big box on its back....Ken

[okcnewbie]

We have a late 90's model 28-29 foot Class C. We live in Oklahoma and almost always have a 20 mph south wind.
We have a little correcting with the really big gusts but other than that it seems to drive much like a large High top van. It's easy to forget you have so much behind you.
Now the mpg's is another thing......ouch!

[hilgert]

Originally Posted by George Schweikle

I almost forgot about bump steer. For those of you who don't know, this is a condition where the steering angle changes when the body leans (Racers go to great lengths to eliminate this). I would have assumed that Ford had addressed this condition.

...

A properly designed front suspension will not change steering angle if the chassis leans. Assuming that Ford class C chassis have bump steer problems due to body lean, my earlier suggestion of adding a track bar isn't necessarily the first corrective measure.

For me, this was 90% solved by the heavier front/rear Hellwig sway bars...made a huge difference in combating lean. After installation it was a night-and-day difference with passing trucks...I could one-hand drive it in the same conditions. On mild corners I don't even take my foot off the gas, and on tighter corners it barely leans if I just slow down a bit (or at least take my food off the gas). We (wife and I) essentially drove this like it was a large fully-loaded SUV (and the wife has a heavy foot...she pushed it past 75mph a few times).

I cannot install a trac bar as I have air bags (it's apparently one or the other), but the rear sway bar seemed to address tail wagging to a meaningful extent (not 90%...maybe the 50% the comes from a sway effect). So some wagging is still there, but it was not an issue in our recent 2600 mile trek with the car in tow. Regarding the air bags, they helped a lot prior to the new sway bars; they help a bit less now since the new bars are doing the majority of the sway control, so they (for me) air bags are for left/right load leveling and ride comfort.

[4x4van]

I have an '88 Jamboree 27' Class C, E350 chassis. For years, it was a white knuckle, E-ticket ride just like the OP describes. I just figured it was because the rear leaf springs were fatigued and allowed the rear to sit lower than it should. Then one day, I got it weighed, front and rear. I had been running about 60-65lbs tire pressure, front and rear. Well, according to the tire pressure charts, while the rear pressure was good, the fronts were too high. I dropped the fronts to 45psi (what the tire chart recommended for the axle weight) and I couldn't believe the difference! It's still not a sports car, but I can actually drive with one hand, eat or drink while driving, and no longer fear big trucks or crosswinds. Of course the rear leaf springs still need to be addressed, but I can now relax while driving.

Lesson? The first thing to do is get it weighed, front and rear, and adjust tire pressure accordingly (ignore the door sticker). 2nd thing to do is a good alignment. If you haven't done either of those two, then it's really kinda dumb to throw money at it yet (shocks, sway bars, etc.).

[hilgert]

Originally Posted by 4x4van

The first thing to do is get it weighed, front and rear, and adjust tire pressure accordingly (ignore the door sticker). 2nd thing to do is a good alignment.

Agree on both. CAT scales are fairly easy to find at larger truck stops. I had mine weighed loaded close to the way we would be traveling, but I still ended up putting (by my choice) close to what the sticker called for (but I know how low I *can* go if desired). Be aware that most tire issues come from under inflation, not over inflation (although ride improves with lower inflation since the tires absorb more of the bumps). My front/rear sitcker is 75/80, and I keep them about 72/78 give or take.

I also have a TPMS for real time pressure and temperature monitoring on all wheels...it's really interesting to see the temperature increase with lower pressure as opposed to higher pressure. Also interesting is the temperature differences between the side of the RV facing the sun versus the shady side.

A proper alignment *for our purposes* would be to add as much positive caster as possible..I could immediately tell the difference in reduced need to constantly adjust the wheel.

[Nia1491]

I have a 16 forester 2251 on Chevy 4500, it drives better when it has full tank of fresh water and gas, its a short and lighter RV, maybe extra weight helps it, i also play around the tire pressure a bit, it also affect the handling ,too. I had a Ford V10 28ft before, did many upgrades on it , and its still gets push around on freeway, especially when its windy, that thing is all over the place. I think when you drive a big box 65miles per hour, can't fight with the wind.

[Traxless]

Last week, we took our '09 MB to a highly regarded alignment shop in Fort Worth. The shop took the LD for a test drive, inspected the complete suspension, and then performed an alignment which included alignment kits. According to this shop, the E450 has limited options to adjust the Caster and the alignment kit allows more options. According to the Service Manager, caster adjustments will improve steering effort and high speed steering/stability. After this service, I drove about 15 miles with some of those miles at 55 mph. There is less play in the steering and steering corrections are less often and smaller. It feels like I have better control and I certainly felt more relaxed.

We're leaving on a longer trip next week, which will include some freeway miles. I'm looking forward to that drive and will report back any feedback.