Side Wind Wander

waukenabo · 06-01-2011, 03:43 PM

We recently returned from the maiden voyage of our 2011 Itasca Impulse 26QP Class C. We were very pleased with it overall. The one major disappointment was the degree to which it wanted to wander in cross winds or when being passed by a truck. Our basis for comparison is the 5th wheel we pulled for 7 years which always seemed rock solid. Is this a common problem/complaint or one unique to me? If it is a common problem, how have others addressed it? Are there after-market products that seem to work? There are a couple of things that may or may not be relevant. I have yet to do the recommended after-build front end alignment. I have rear air springs. And, after about 2000 miles it seemed to get easier – I relaxed more and over-corrected less. However, driving the unit still wears me out and takes some of the fun out of getting around in it.

RVRon · 06-01-2011, 06:35 PM

Waukenabo,
When we experienced the same thing you describe with our 31 class C, I installed Bilstien shocks and that cured about 90 percent of my problem. You may have different results.

RV'nOldTimer · 06-01-2011, 06:48 PM

Quote:

Originally Posted by waukenabo

We recently returned from the maiden voyage of our 2011 Itasca Impulse 26QP Class C. We were very pleased with it overall. The one major disappointment was the degree to which it wanted to wander in cross winds or when being passed by a truck. Our basis for comparison is the 5th wheel we pulled for 7 years which always seemed rock solid. Is this a common problem/complaint or one unique to me? If it is a common problem, how have others addressed it? Are there after-market products that seem to work? There are a couple of things that may or may not be relevant. I have yet to do the recommended after-build front end alignment. I have rear air springs. And, after about 2000 miles it seemed to get easier – I relaxed more and over-corrected less. However, driving the unit still wears me out and takes some of the fun out of getting around in it.

Have you weighed the four corners and adjusted the air pressure to the tire manufacturer's recommendations for the load? When we picked up our Journey, it had some of the same characteristics you mention until we discovered the tires had the max pressure allowed. After adjustment according to weight the improvement was substantial.

JT

cliff841 · 06-01-2011, 09:41 PM

Many on the forum have recommended rear track bars as the first aftermarket step to take to solve this problem. I face it as well and I plan on adding a rear track bar and a safe-t plus next week. I was advised from the forum to check my tires and found they were inflated to a much higher pressure than necessary. Adjusting this made a big difference.

cliff841 · 06-01-2011, 09:44 PM

Waukenabo I just realized you have a class C. My post is based on my research on my class A. I don't know nearly enough about the topic to know if my post is relevant. If it is relevant, know that it is based on advice from this forum and some service people I spoke to.

Finhawk · 06-01-2011, 11:13 PM

Check out the SteerSafe web site and then give them a call. Mine did the same thing and that was the cure

waukenabo · 06-02-2011, 01:58 PM

Thank you, everyone. I'm not sure where I'll find a place to weigh all four corners but I can at least start by weighing each axle and adjust pressure accordingly. I'll also look into the products you recommended.

The Shadow · 06-03-2011, 03:21 PM

Quote:

Originally Posted by waukenabo

Thank you, everyone. I'm not sure where I'll find a place to weigh all four corners but I can at least start by weighing each axle and adjust pressure accordingly. I'll also look into the products you recommended.

IF you get it weighed, how about posting details here? We have the same unit and tow an Escape. I did not notice any severe problems with the wind. It moved around a bit but when you watch 18 wheelers getting moved around when loaded down, no reason we'd not be doing a bit of the same in a heavy wind.

I'm surprised you never felt the impact of the wind with your 5er given how much lighter it is than an 18 wheeler and the amount of sail area it has.

This is our 5th MH and its handling is no better or worse than the previous 3. The first was on F53 and was AWFUL on a rough road with a heavy wind. It could take either on their own but with both it was terrible and the steering correction made DW upset just watching me. A Davis TruTrac made a huge improvement.

To this point (to Florida and back on I-75) I've not concluded I want to make any additions. It does have a steering stabilizer (small compared to a Safe-T-Plus) but I've not concluded the heavier unit is necessary. Perhaps if we hit much stronger winds - 25 mph or more - my view will change.

Don

RV'nOldTimer · 06-04-2011, 09:19 PM

Quote:

Originally Posted by waukenabo

Thank you, everyone. I'm not sure where I'll find a place to weigh all four corners but I can at least start by weighing each axle and adjust pressure accordingly. I'll also look into the products you recommended.

If you can't find a way to weigh each corner, weigh each axle (most truck scales can do this), calculate the average weight on each tire, do the weight table thing and add five pounds pressure as a "fudge" factor. That's better than many plans.

JT

offthewall · 06-04-2011, 10:16 PM

Quote:

Originally Posted by waukenabo

We recently returned from the maiden voyage of our 2011 Itasca Impulse 26QP Class C. We were very pleased with it overall. The one major disappointment was the degree to which it wanted to wander in cross winds or when being passed by a truck. Our basis for comparison is the 5th wheel we pulled for 7 years which always seemed rock solid. Is this a common problem/complaint or one unique to me? If it is a common problem, how have others addressed it? Are there after-market products that seem to work? There are a couple of things that may or may not be relevant. I have yet to do the recommended after-build front end alignment. I have rear air springs. And, after about 2000 miles it seemed to get easier – I relaxed more and over-corrected less. However, driving the unit still wears me out and takes some of the fun out of getting around in it.

First off. Make sure you are running the correct tire pressures for your weight. Start with the door sticker pressures until you can get a four corner weigh. Get a wheel alignment, Class C MH's are always off when delivered. If you are still unhappy after an alignment and pressure adjust, consider changing shocks and steering dampener with higher quality units (Monroe or Blisten). After that, you can upgrade your front and rear stabilizer bars.

We did all of the above, with the help of an experienced truck chassis guy and it transformed the handling of our 31' class C from scary to VERY comfortable. These class c truck chassis are running at their limits and need to be fine tuned if you want a comfortable drive.

waukenabo · 07-18-2011, 01:53 PM

Thanks everyone for the advice you've offered. A couple of you asked for feedback on the steps I've taken. I had the post-build alignment done. Although I've since driven only 150 miles in a moderate wind, there seems to be a noticeable improvedment in handling. The alignment specialist also told me that the alignment was off by enough that I would have had significant wear on my front tires. So, there are a couple of good reasons to do the recommended post-build alignment on Class Cs. I also weighed all four corners and softened pressure both front and rear by 10 lbs according to Michelin's recommendations. I was pleased to see that the side-to-side weight difference was only about 200 lbs. I have no experience yet with the softened tires. However, we leave on a 3000 mile trip this week so I will certainly have an opinion by the time we get back.

The Shadow · 07-18-2011, 04:03 PM

Quote:

Originally Posted by waukenabo

Thanks everyone for the advice you've offered. A couple of you asked for feedback on the steps I've taken. I had the post-build alignment done. Although I've since driven only 150 miles in a moderate wind, there seems to be a noticeable improvedment in handling. The alignment specialist also told me that the alignment was off by enough that I would have had significant wear on my front tires. So, there are a couple of good reasons to do the recommended post-build alignment on Class Cs. I also weighed all four corners and softened pressure both front and rear by 10 lbs according to Michelin's recommendations. I was pleased to see that the side-to-side weight difference was only about 200 lbs. I have no experience yet with the softened tires. However, we leave on a 3000 mile trip this week so I will certainly have an opinion by the time we get back.

Would you might posting the weights by corner and let us know what you were carrying with respect to water, fuel, "stuff" etc?

Don

TXiceman · 07-18-2011, 06:03 PM

Steer Safe and other steering stabilizers cover up the problem and do not fix it.

Start by weighing the rig when loaded for travel, adjust tire pressures accoring to actula loads, do not carry more than 1/4 tank of fresh water and get the front end alignment check by an independent truck shop while loaded.

If these steps do not help, the next thing to do is Roadmaster or Hellwig anti-roll (sway) bars with urethane bushings and Bilstein shocks.

The E450 chassis is woefully short on roll controll and has a tendency to roll from side to side which requires steering corrections.

we went through these issues with the our 31' class C and after the ant-roll bars and shocks, it was a dream to drive.

Ken

waukenabo · 07-19-2011, 01:02 PM

Don,
My weights were:
LF: 1880
RF: 2020
LR: 4000
RR: 4080

I had less than 1/2 tank of gas, a nearly full fresh water tank, empty black and grey water tanks, and a full propane tank. I was also loaded as we normally travel except for food and clothing. When I estimated total traveling weight for figuring tire pressure, I added 300 lbs for additional fuel, 100 lbs each for clothing and food, and 400 lbs passenger weight. I divided that evenly between left and right (a guess) and 1/3 to the front axel and 2/3 to the rear (also a guess). By the way, I tow a Honda CR-V so you and I travel in very similar fashion.

The Shadow · 07-19-2011, 03:59 PM

Quote:

Originally Posted by waukenabo

Don,
My weights were:
LF: 1880
RF: 2020
LR: 4000
RR: 4080

I had less than 1/2 tank of gas, a nearly full fresh water tank, empty black and grey water tanks, and a full propane tank. I was also loaded as we normally travel except for food and clothing. When I estimated total traveling weight for figuring tire pressure, I added 300 lbs for additional fuel, 100 lbs each for clothing and food, and 400 lbs passenger weight. I divided that evenly between left and right (a guess) and 1/3 to the front axel and 2/3 to the rear (also a guess). By the way, I tow a Honda CR-V so you and I travel in very similar fashion.

Thanks. Those numbers leave lots of room and tie in nicely with the weight sticker on my 26QP. I figured that if the UVM (unloaded vehicle mass as it states on the sticker) was close to the sticker, there was no way we'd ever have an overweight problem - or anything even close. The only aspect I wondered about and was going to have it weighed for was front/rear and left/right distribution. Now, I'm not even going to bother with that since mine should be virtually identical to yours.

Thanks again.

Don

BTW, there is a YAHOO group for Winnie-Itasca Class C motorhomes now. Click the link below.