With the economy being what it is, we are seeing more and more RV owners choosing to hang on to their rigs and fix them up, rather than trading up for something new. Realistically, it just makes sense-because for the cost of a couple of payments, you can often make your rig as good as new-or even better in the case of a customer’s rig we have in our shop right now.
He owns an ’02 International 4700 medium duty truck towing an ’02 Travel Supreme triple-axle fifth wheel. The truck has over 115,000 miles on it, and recently returned from a trip to Alaska where it was driven over some pretty rough roads. The customer complained about a rattling noise, and that it was riding “heavy”. The rear air suspension was taking a long time to level out, and he indicated that he was having difficulty keeping the truck in its lane.
Well the original shocks had seen better days, and not being able to fit Road King shocks on this particular truck, we went with Koni shocks instead. This made a huge difference in the way the truck rode. Upon further inspection, we realized the cause of the leveling problem: The rear air suspension was not equipped with an air dryer, and the leveling valves and relay valves were loaded with moisture. This is a fairly common problem on trucks like these that have air suspension, but not air brakes; air brake trucks move enough air so that the manufacturer feels an air dryer is justified. Without an air dryer, the water tank must be drained at least every month or so to prevent water from collecting in the system and you’ve got to crawl under the truck to do it. So we replaced his compressor with a rebuilt one (there was evidence of oil in the ride height valves, too-caused by a compressor that’s going bad), installed new ride height valves and an air dryer to prevent moisture build-up in the future.
Wander is a common problem with straight-axle vehicles, and they often don’t return to a positive center. To combat this problem, we installed a Safe-T-Plus steering stabilizer. In case you’re not familiar with this product, the Safe-T-Plus is a hydraulically dampened,mechanically self-centering device that keeps the vehicle tracking straight. Because it’s self centering, it also greatly reduces rut tracking, where the tires follow grooves in the road. And finally, as I’ve discussed in previous posts, it can even improve mileage and reduce tire wear. How? The less you are working the steering wheel, the less resistance you are creating and the less scrub on the tires.
The owner is now thrilled with his truck, which rides smoother and tracks straighter than it did when it was new. In the next post, we’ll talk about some of the major improvements we made to the fifth wheel as well.