RV Suspension and Alignment
There are various suspension systems used on RV trailers with the most common being the leaf spring or "buggy" spring system. This worked well in the horse and buggy days and is a carry over from that time.
It is referred to as a leaf spring because there are several slender sections layered upon each other to provide the required stiffness or load carrying capacity while at the same time being flexible enough to absorb the shocks of road travel.
Either end of the main leaf spring is attached to a spring hanger on a single axle trailer or to a spring hanger and an equalizer on a tandem axle setup. The ends of the springs are rounded into an eye shape to allow them to be mounted onto a bolt and each point must be able to pivot around that bolt. A plastic or nylon bushing (see replacing bushings) is inserted in every pivoting point on the suspension system to take the wear and tear on these parts. These bushings should be inspected periodically, depending on mileage, and replaced as required. As they wear, they allow more "sloppiness" in the suspension, resulting in unnecessary tire wear and other related problems.
The weight of the coach is carried by the ends of the springs and the center of the spring is bolted to the trailer axle which, of course, is attached to the wheels and tires. This whole arrangement provides a smooth ride for the trailer, with the springs absorbing the unevenness of the road surface. Further dampening of road bumps is provided by the use of shock absorbers.
To minimize wear and stress on the wheel bearings and tires, it is imperative that the tires are pointed in the right direction and at the proper angle relative to the road surface. This is called camber and castor by wheel alignment gurus and it is beyond the scope of this writers expertise to explain the complexities of these matters.
However, tire wear patterns will indicate certain alignment problems and suggests the repairs required to fix the misalignment. An out of balance wheel or a bent wheel will cause a cupping wear pattern in the tires circumference. An improper camber alignment will wear the tires on one side more that the other and an improper castor angle will scrub off rubber in various ways.
The average RV dealership or repair facility is not equipped to handle this type of repair and it is definitely not a do-it-at-home project. Only an alignment shop with the neccessary equipment and trained personnel should be called upon to adjust the trailer wheel alignment. Most major cities will have at least one of these specialized shop. Check with your local dealers for a reference.