Inspecting and Replacing Subaru Ball Joints

For many people, purchasing a car is an exciting experience. It is particularly exciting when purchasing an impressive sport compact car such as a Subaru STI for sale.

But, such a vehicle needs to be carefully inspected before purchase. One thing to check is the ball joints. Here's how:

Background to Subaru Ball Joints

The ball joint on this style suspension is located at the bottom of the wheel bearing housing. Its purpose is to allow the wheel bearing housing to rotate around the axis of the ball joint. The ball joint supports the bottom of the bearing housing, and lets it rotate with the steering wheel through the steering rack.

Rotation for the top of the wheel bearing housing is handled through the upper strut mount. This mount contains ball bearings in the top that allow it to rotate.

The ball joint is considered by some people to be a weak point in the MacPherson suspension. If the ball joint fails, that wheel will lose steering control and could result in an accident. So that's why it is important to inspect the ball joints regularly and make any replacements or repairs as required.

How to Inspect Subaru Ball Joints

One of the simplest ways for the do-it-yourself Subaru enthusiast to inspect the ball joints on a Subaru STI that is for sale is to lift the front wheels off the ground and set it on jack stands. Naturally getting underneath a vehicle supported only by a jack is not wise.

Then, a cinder block is laid near the wheel bearing housing. Next, a large pry bar is used to try to wiggle the control arm up and down while leveraging against the cinder block. If any free play is noted or felt at the ball joint, it should be replaced. The specifications usually allow one to a few thousands of an inch free-play, but this is essentially nill for all practical purposes.

Replacing Subaru Ball Joints

The pinch bolt at the bottom of the wheel bearing housing is normally the hardest part of the replacement. On older Subaru vehicles or those that have been in the rust belt more than a couple years, this bolt will usually snap off, even if heated and if penetrating oil was used liberally. So then it must be drilled out and re-tapped. Therefore, the services of a professional mechanic are usually sought for this job.