Softening the Ride E-450 Class C

[LarsMac]

Sorry to be a techie nitpicker, but "anti-sway bar", "track bar", and "steering stabilizer" are all different things that address different problems. Anti-sway bars have nothing to do with steering, but the other two devices will have some effect on "drift". Probably the track bar is the best bet if the problem is correctly identified as drift. Nothing you have described sounds like a sway bar problem.

I've written an article on Motorhome Handling problems and improvements and in it's in the RVForum Library at Motorhome Handling
If nothing else, it should acquaint you with the types of problems and what addresses them.

Excellent article. Thanks.


[quote author=Gary RV_Wizard]
Shock absorbers are misunderstood by most laymen. They aren't there for ride comfort, they they do have some side effect.  The purpose of a shock absorber is to prevent the wheel/tire from losing contact with the road when the suspension rebounds after hitting a bump or hole.  The suspension absorbs the initial hit by compressing, but then the suspension rebounds, lifting the wheels and throwing passengers upward.  The shock is supposed to dampen that rebound motion. Faulty shocks or inadequate ones allow what is called porpoising, where the suspension repeatedly bounces up/down after the initial strike. Doesn't sound as though you have that problem.
[/quote]

Yep. Back in my days as a wrench-turner, I had to explain that to a number of customers.

[quote author=Gary RV_Wizard]

Your problem very much sounds like excessive tire pressure, but it may simply be that your expectation is a passenger car ride. That ain't gonna happen.
[/quote]

That seems to be the consensus. I have some leeway with tire pressure. Though when we first started out, I found that 70 psi or below, the steering seemed bit mushy, And on the trip back West, I settled on 75 for the return trip. Perhaps dropping the drivers down a few lb might help. I have a road close by that will serve as a test track, and will play with the pressure variations.

I'll keep a log and share if I end up with any useful data.

 

[Gary RV_Wizard]

75 psi doesn't sound excessive, but the only way to know for sure is to evaluate the axle or individual wheel loads vs psi.  I'm guessing you have LT225/75R16E tires with a max load pressure of 80 psi, so 75 is probably about the minimum for carrying a loaded E450.  The fundamental problem is the E450 is pretty close to fully loaded (14,050 lbs) with a 30 ft coach built on top, even before adding passengers and gear.

 

[ChasA]

I recently had my coach weighed (4 corner) at Freightliner in Gaffney.  They also adjusted tire pressure accordingly. I had been running 90 psi in front and 100 psi in rear. They changed to 90 psi all around and the difference is a noticeably smoother ride. I wouldn't have thought a 10 psi difference in the rear would be that noticeable.

 

[Utclmjmpr]

That would be 10 pounds multiplied by 4 times at the rear,,, a significant difference..>>>Dan

 

[Gary RV_Wizard]

That 10 psi may not seem like much, but at the rear duals it is a difference of about 1500 lbs of carrying capacity for your tire size.  You've softened 1500 lbs worth.

 

[matlack]

Air suspension is not a guarantee of a pillow soft ride. The ride on my '05 Dutch Star was horrendous at times on rough roads - bone jarring. A dream on relatively smooth roads, quiet and silky. But my F-250 rides better on rough roads.


I had a four bag suspension system (1 per wheel). I suspect newer, more advanced (and more expensive) suspension systems are better, but I was quite disappointed. A Greyhound bus (i.e., Prevost) rides much, much better. But then, the chassis alone cost nearly as much as my rig did new.

I have an idea to get a Prevost chasis under my '94 Isuzu Safari Trek that I have owned for 16 years. Am I crazy? No rigs are designed for livaboards like me-mainly, no windows. But the full leaf spring suspension of the NPR truck chasis is over for my body. Rather than buy a "camper" for 190,000, I'd be willing to pay for a chassis exchange. Any ideas out there. New member here.

 

[Gary RV_Wizard]

What are you suggesting, Matlack? Physically moving the Trek body to another chassis, or buying a Prevost (or other bus) conversion with its own camper body? If the latter, why Prevost? There are plenty of air suspension coach brands available, built on chassis designed for Class A motorhomes.

 

[matlack]

What are you suggesting, Matlack? Physically moving the Trek body to another chassis, or buying a Prevost (or other bus) conversion with its own camper body? If the latter, why Prevost? There are plenty of air suspension coach brands available, built on chassis designed for Class A motorhomes.

Gary- Yes! I love everything about my old trek except the ride. I crave info from knowledgeble people. I am a big thinker. I would go to great length and expense to preserve my Rig. Maybe we could talk on the phone? I am in Bradenton. also overall length max at 28.
bruce