Quote:
Originally Posted by beedub
A few years ago we were at a rally where the organizers were doing the individual weights for the attendees at no charge. I spent some time with the man doing the weights and he said after doing thousands of units, there NEVER has been one that wasn’t different side to side. All RVs going down the road are off to some degree and I would challenge anyone to site a case where this was a contributing factor in an accident.
Coach manufacturers have engineers who design the setup of these coach’s and I can’t believe amateurs are second guessing the manufacturer and making changes to these very complicated and expensive machines. The frame and running gear are made by companies that specialize in this and this is not the same as a fridge or slide issue.
If you suspect a problem with the weight, ride and handling of your coach, take it back to the manufacturer or their dealer and make sure the verdict is documented for future reference.
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Greetings Beedub,
I don't know if you are referring to me being the" amateur second guessing the engineers" or just generalizing. Either way, I worked in two industries that involved engineered plans. I can tell you from 20 years of personal experience building things engineers have designed, that I have no problem second guessing them. And yes, all coaches will be heavier on one side than the other. But remember that ONE chassis design is used on many completely different lengths and floor plans with vastly different weight distributions, and the air ride system is the exact same for all of them. Also, I do have experience with several coaches, and know for a fact that the more balanced a rig is, the better it is.
For those that don't know, there have been many coaches improperly designed by engineers. Or, if not improperly engineered, they were improperly executed. For example, Newmar had to replace the entire front axle on many of their 2016 Dutch Star coaches and Tiffin had to re-design the drive/tag axle air ride system on their Allegro Bus models due to the problems they had. I had to change out both the tag axle air pressure regulators, and the dump valves on my 2014 Allegro Bus 45LP, with new parts that Tiffin supplied, because of front axle weight issues.
Now, I agree completely that the imbalance in my coach, or any other I've seen, is not dangerous in any way, and would not be the cause of an accident. Frankly, I feel that many slide systems are indeed more complex, and they have far more adjustments that all have to be correct for the slides to operate as they should. But, the air ride system on my coach in not in any way complex, complicated, or expensive. It is the same basic analog/mechanical system that is run on every semi truck made. I see no reason that I should not make it better if I can. Especially since my front axle is often at, or over its 19,000 lb. GAWR. I know that with small adjustments to the upper and lower ride height parameters, I can make it better.
I have talked to both Spartan and Newmar about my unit, and their only response has been to check that the ride height is correct, which it is, and to distribute my load differently even though I am 5,000 lbs. under the GVWR. Spartan/Newmar decided to save a few bucks and only use one ride height valve and dump valve on the rear axle. Two would be better and allow better side to side weight distribution. Also, their own engineered air system diagram that they sent to me, shows an air pressure regulator between the drive axle and tag axle air bags to make the tag axle air pressure adjustable, but it's not there. Engineering vs implementation?
So, I have added 12 feet of air line and two $8 regulators to make make that change. Going from the 75 psi the tag axle had, and dropping it down to 50 psi, will take weight off of the front axle and add it to the drive axle where it is needed. Next is a trip to the scales to verify the weights, and to make further adjustments if needed. I am not willing to drive 3,000 miles round trip to Newmar, to fix what I can do in my own driveway in a few hours, with $20 of parts, and a few trips to the scales.
Overall, I am really happy with my Newmar compared to the competition. I do wish none of this was needed, but I feel it is, so I am doing it. I am sure that others might make different decisions. Now, if I could just get all my windows to quit separating, life would be good!
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