Sightseeing while driving is something we all enjoy. When your motorhome wanders, it can take the fun out of your journey. You know, you look away for just one second, and your motorhome is on its way out of the lane. It requires constant attention to keep it going in a straight line.
We call this issue “road wander”. Between the steering wheel and the front wheels, there are a lot of components. There are couplings, the steering gear, the sector shaft, pitman arm, drag link, bell crank, tie rod ends, etc. Too much play in one or more of these components can make the front wheels have a mind of their own. To diagnose road wander, first, we take the coach on a Road Performance Assessment (RPA) to see how it behaves. If we can rule out “tail wagging the dog” as a handling problem, then we focus on the front of the coach. For road wander, we’ll pick a nice, straight flat section of highway and hold the wheel straight. If the coach changes direction on its own, we know that wander is the concern.
To diagnose the cause of road wander, we put the coach on a lift and check every single component that contributes to the steering. One of the first things we’ll look at is the steering gear box. Motorhomes use a reciprocating ball type steering box. They usually have a certain amount of play in them by the nature of their design. Next, we’ll look at the "pitman arm". This is steering linkage that attaches to the steering gear box. Some pitman arms have joints that can be replaced if they wear out. Sometimes, the joint simply wasn’t tightened down properly at the factory and has come loose. The “sector shaft” comes out of the steering box and has splines on it. If the nut wasn’t tightened down properly, there could be play in the splines. The shaft may also have been damaged in an accident of some kind.
An Idler arm or Bell Crank supports the linkage in some steering systems. The P32 and the Freightliner XC chassis with a straight axle to be exact. SuperSteer designed and built Bell Cranks specifically for these chassis.
Front axle walk is when the axle moves from side to side. This can cause steering wander on the Ford F53, Workhorse and FRED chassis. These chassis have leaf springs on the front. In these instances, the problem can be rectified by a front Trac Bar. We carry a Roadmaster product for these applications. We are also able build a custom Trac Bar for some of those old John Deere and Oshkosh chassis, as well.
In some instances, the motorhome may have a lot of rear overhang, which makes the coach light on the front axle—especially if the coach has a short wheelbase. The solution here is to add weight to the front axle (while remaining well within the front GAWR) to make the vehicle track properly.
Another consideration for road wander is the tires. Therefore, you should pay particular attention if you’ve just replaced them. We had an experience on the vehicle that we use to travel to shows. We replaced the tires with a different brand than we normally use. The van seemed like it was all over the road. It was so bad, in fact, that we stopped at another dealer, as soon as we could, to exchange the tires for our usual brand. A narrow tire, such as an 8R19.5 can get into ruts. Also, different tread patterns and sidewall construction can also be contributing factors.