Tuesday, January 28, 2014

Beware of Tire Wear! (Part 1 of 3)

Towing a camper of any kind adds a large amount of weight to your tow vehicle.  If the weight is uneven, or if there are mechanical issues with the tow vehicle that are not immediately obvious, tire wear may occur.  Analyzing the type of tire wear that appears can help in determining what the issue is, and can prevent major mechanical issues from occurring.  To help illustrate the types of tire wear, our service department has put together an informational binder, available in our service waiting area (and now here online!).

One Side Wear
When an inner or outer rib wears faster than the rest of the tire, the need for wheel alignment is indicated.  There is excessive arching in the front suspension, causing the wheel to lean too much to the inside or outside and putting too much load on one side of the tire.  The car may simply need the wheels aligned, but misalignment could be due to sagging springs, worn ball joints, or worn control arm bushings.  Because load has a great affect on alignment, be sure the car is loaded the way it's normally driven when you have the wheels aligned; this is particularly important with independent rear suspension cars.

Second-Rib Wear
Second-Rib wear is normally found only in radial tires, and appears where the steel belts end in relation to the tread.  Normally, it can be kept to a minimum by paying careful attention to tire pressure and frequently rotating the tires.  Some car and tire manufacturers consider a slight amount of wear at the second rib of a radial tire normal, but that excessive amounts of wear indicate that the tires are too wide for the wheels.  Be careful when having oversize tires installed on narrow wheels.

Cupping
Cups or scalloped dips appearing around the edge of the tread on one side or the other, almost always indicates warn (sometimes bent) suspension parts.  Adjustment of wheel alignment alone will seldom cure the problem.  Any worn component that connects the wheel to the car (ball joint, wheel bearing, shock absorber, springs, bushings, etc.) can cause this condition.  Worn components should be replaced with new ones.  The worn tire should be balanced and possibly moved to a different location on the vehicle.  Occasionally, wheels that are out of balance will wear like this, but wheel imbalance usually shows up as bald spots between the outside edges and center of the tread.

In part two of this section on tire wear, we'll go over 'feathering', 'under inflation' and 'over inflation'!