Be Informed When You Make Joint Decisions

The first sign of trouble in a car is often a barely audible noise, something that a car owner doesn’t even recognize. But those soft nothings often herald big money repairs.

In the case of constant velocity joints, the noise begins as a sort of clicking in the front end that can be barely heard when accelerating in a turn. But soon enough the noise grows and the realization comes that something is wrong down there.

Constant velocity joints allow an axle on a front-wheel drive to bounce up and down with the wheels while being attached to the stationary transmission. Each of a car’s two axles have two joints, an inner and an outer. The joints typically fail when the rubber boot around them splits open and allows dirt and water to penetrate the permanent grease inside.

Faulty joints eventually make horrendous noise. Most motorists replace them long before they catastrophically fail. A vigilant mechanic will often warn a car owner when the boots are getting ready to split and suggest replacing them. The replacement of the boots, however, isn’t cheap and requires nearly as much labor cost as a later replacement of the entire joint--meaning a simple boot replacement can cost more than $200.

Experts advise that a boot replacement is a good value, although many motorists balk at spending hundreds of dollars on such speculative maintenance.

By the time you hear a joint making noise, it is generally too late to perform preventive work, and you are headed for a bill of anywhere from $200 to $1,000, depending on how many joints need repair.

If you are well-informed and do some shopping, you can save yourself hundreds of dollars. You have three options: a new axle assembly, a remanufactured axle assembly or replacing the failed joint on your old axle with a new joint.

Few mechanics will give you a choice, however. They will simply quote you a price for a repair. But you should ask what you are getting and check around to see if an alternative might be cheaper.

Almost nobody suggests that you buy a new axle assembly, although many dealers will try to slip it into a repair job. A good-quality remanufactured axle should be equal to a new axle and cost hundreds less.

The choice between a new joint and a remanufactured axle is a closer call. A remanufactured axle requires less labor than a new joint to install, but the axle costs more. Companies such as Dana, which makes only new joints, insist that a new joint assures a motorist of higher quality.

One advantage of a remanufactured axle is that both the inner and outer joints are inspected, lubricated and get new rubber boots. But there are hundreds of remanufacturers, some of whom use poor procedures. If you opt for this repair, look for parts marketed by a major axle house, such as Moog, Neapco or Federal Mogul.

* Vartabedian cannot answer mail personally but will attempt to respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, 1875 I St. N.W. #1100, Washington DC 20006.