# Kelderman Air Suspension System



## al3282 (Sep 26, 2008)

Kelderman has a recurring ad in MotorHome on a retrofit air suspension system for the F-53 Ford chassis. Their website claims it changes a dump truck ride to one resembling a Greyhound bus. That analogy pretty well describes the ride we get from our 99 Pinnaclechasssis. The basic parts of their system appears to be softer front leaf springs, an air bag and Monroe shocks. In an attempt to improve our ride we had Monroe's installed about five years age and Goodyear 670RV tires about two years ago. Neither imroved our ride. Anybody out there with any experience on the Kelderman system? I talked with them this AM and they seem to have a lot of experience with what their system does on an F-53 chassis.


----------



## Paul235 (Sep 26, 2008)

RE: Kelderman Air Suspension System



Here's an article by the RV Doctor, Gary Bunzer. He seems knowlodgeable about handling problems. Based partly on his opinion, I replaced "very" worn out shocks with Bilsteins and installed a Davis Tru-Trac. Made worlds of difference with front end. Also check closely how much air is in the air bags in the rear if you have them. I can put 80lbs in mine and turn the coach into a spine shaker. Mine use 30-90lbs depending on weight in the coach. Kind of long but well worth reading. 




   Improving Motorhome Ride, Steering and Handling    *By Gary Bunzer *

   Ever dream of climbing aboard your home on wheels, settling into the driver's   compartment, buckling up and heading off to experience the vast panorama in a   smooth, relaxing, enjoyable driving environment? Tackling the curves as you   would with an equally priced, specialty race coupe, with a latte in one hand   while the other effortlessly caresses the steering wheel and guides your   steed blithely through the twists and turns on endless ribbons of concrete?   Or are you like many RVers who are forced to literally maintain a   white-knuckled death grip on the wheel with both hands, fighting a mere 5 mph   side breeze, constantly correcting the steering wheel, wracking back and   forth so violently your holding tanks always read "Full"? Does the   strain on your back and neck have you questioning whether you are indeed in   your motorhome or on some exotic thrill ride at Wally World? 

   In truth, many, if not most, of today's motorhomes do experience some   not-so-pleasant nuances with ride, handling, steering and suspension.   Typically, it all relates to weight distribution and methods of counteracting   the physics of propelling a motorhome down the road. Thankfully, the   aftermarket is rife with products that can and will address those issues as   they relate to the specifics of each motorhome. Is that to say your motorhome   will gain the uniqueness of that sporty race car? Not quite, but your new   vocabulary will include phrases like, "vastly improved,"   "easier handling characteristics" and "much safer." Plus   that pounding headache will go away.

   Any discussion among veteran RVers will yield an assortment of concerns which   include subjects such as tires, front end wander, rear end sway, rut tracking   and that porpoise-like up and down oscillating. And since every coach   displays different symptoms based on the design characteristics of that   coach, there is no single fix that will fit across the board. What may work   on one RV, may not on another. In fact, because each coach is so inimitable   and each symptom so specific, specialty shops abound that deal exclusively   with improving motorhome ride. If you are an RVer who understands from whence   I speak, take heart, for there are solutions. 

   The first thing to investigate during any preemptive troubleshooting foray   into ride and handling problems centers on weight distribution. Face it, RVs   in general and motorhomes specifically are not created symmetrically nor is   the weight equally placed on the chassis. In fact, John Anderson, Executive   Director of the Recreational Vehicle Safety Education Foundation states that,   "Of all the RVs we've weighed (over 10,000 RVs in seven years); we've never   come across one that was loaded equally on both sides." (emphasis mine)   It is vital then, that the astute RVer know exactly how much the coach weighs   as loaded for travel. In no area is this more important that the motorhome   tires. Knowing how much weight each tire location is carrying is virtually   the only way to know how much air pressure to pump into each tire. Over or   under inflation alone can breed a plethora of steering, handling and safety   worries. Additionally, the Goodyear Company stresses the importance of proper   tire sizing and load range choice for each gross axle weight rating. 

   As for all other steering, handling or sway issues, always begin by ensuring   your rig is set up with the correct front end alignment at factory specs   before adding equipment and components. Also, according to Kevin Healy, owner   of one of the preeminent specialty shops, East County Alignment & Brake,   always have the stock springs tested and evaluated prior to slapping on   replacement parts. Granted, aftermarket products will indeed improve   drivability, but having the correct spring rate is vital to knowing which   combination of aftermarket products will do the most good. Since it could be   a substantial investment to rectify all ride and handling ills, the smart   RVer will seek the biggest bang for the buck.
             No talk of front end remedies   omits the name Bilstein. Simply put, if your coach is not already equipped   with Bilstein shocks, get some. This upgrade is the most common aftermarket   replacement component in use today. For the larger diesel pusher rigs, it's   not uncommon to find four Bilsteins added to the rear end also. 

   More front end improvement is realized with the addition of the Davis   TruTrac(tm) Bar. Developed by RV chassis expert Eric Davis, this bar allows   for a stricter control of the motorhome with less effort exerted by the   driver. The TruTrac(tm) holds firm the contemptible front axle side to side   movement that can turn a leisurely RV excursion into a driving nightmare. If   front end wander or rut tracking are frequent experiences for you, the   TruTrac(tm) Bar is a necessity. 

   To avoid worry over severe tire oscillations on bumpy roads, or loss of   control during a front tire blowout or a sudden shudder caused by a passing   truck, there are a couple of cures to consider. Steer Safe and Safe-T-Plus   are the front runners in the steering damper area. Designed to keep the front   wheels between the ditches at all times, either of these two comparable   add-ons are on most RVers want list. Coupled with the aforementioned Bilstein   shocks and Davis TruTrac(tm), the inclusion of either of these steering   stabilizers rounds out the most popular, three-component upgrade package for   motorhome front ends today. Though each addresses basically the same steering   symptoms, the Safe-T-Plus employs sealed components which could be a factor   if you travel in areas where salt, ice and moisture are prevalent. 

   Do you constantly over-steer your motorhome as you travel down the road? The   need to continuously wrestle the steering wheel just to stay straight could   also be caused by a not-so-pristine steering control mechanism called the   bell crank. Thankfully Henderson Line-Up Brake & RV has developed a   superlative replacement product, the Super Steer Bell Crank. Many motorhomes   built on the older Chevrolet and GM chassis especially are prone to rapid   bell crank fatigue due to inferior bearing design. The result was a need for   a rebuild or a replacement after just a few thousand miles. The   maintenance-free Super Steer Bell Crank uses precision tapered Timken   bearings and is completely sealed against road debris and moisture. 

   Ah, but not all ride and handling problems are limited to just the motorhome   front end. Rear end sag or sway, the tail wag the dog syndrome, are also   problematic for many coach owners. Again the aftermarket proffers up the   fixes. Air bags and a heftier rear stabilizer bar will effectively address   the sway problem and body roll tendencies of boxy motorhomes. Once again the Henderson   brothers bring a solution to the mix with their Super Steer Rear Stabilizer   Bar. A larger diameter bar and improved, high-strength polyurethane bushings   are all features of most aftermarket rear sway bars. It's seldom argued that   virtually every motorhome will ride better with a larger sway bar.

   Air Lift air bags just may be the solution if your rig is drastically out of   balance front to rear. Rear end sag is not only unsightly on people, but   likewise on motorhomes. Plus this imbalance reduces the downward force on the   front axle, thereby negatively affecting the front end suspension and   steering characteristics. The obvious fix is to raise the rear end, shifting   some weight forward onto the front axle resulting in better steering and   handling up front. Simply adding leaf springs, however, creates a stiffer,   less flexing alternative. If your driveway displays the tell-tale gouges in   the concrete from the ball mount on your motorhome, or you look like Flipper   going down some roads, perhaps it's time to consider a rear air bag system.   Do remember there is an Air Lift kit for every motorhome.

   Without a doubt, RV owners of yesteryear never had as many aftermarket   opportunities to improve upon ride and handling as do RVers of today; most   just suffered in silence, drifting from RV to RV hoping for a better ride at   each trade. Thanks to the diligence and ingenuity of some bright minds, there   are better mousetraps out there. Indeed today's coaches are better than ever,   but with each body size, floor plan design, wheelbase dimension, weight   distribution variance, and chassis brand, comes the need for pinpoint   troubleshooting to determine which products will offer the best possible   solution for common front and rear ride tribulations. Once that is   determined, one quick trip to your local RV Service Center will have you   sipping that latte in no time while allowing the blood to finally flow to   your knuckles once again.


----------

