At 12:46 PM 8/30/2003, sertan wrote:
> How can I understand balljoint failure ?How can check it? When I press the brake pedal hard (panic braking) My car moving head left to right.
> 86 928s 4,7 16v Thanks

To check the lower ball joints: Jack the car with the jack placed on the lower suspension arm as close to the lower ball joint as possible. When the tire is off the ground, use a pry bar under the tire to lift the tire and check for movement in the ball joint. Some movement is acceptable.

To check the upper ball joint, use a very large pair of slip-joint pliers to squeeze the upper suspension arm down on the spindle and check for movement between the suspension arm and spindle. There should be almost no play in the ball joint.

Other things that can cause darting under braking:
Loose tie rod ends, either inner (at the steering rack) or outer (at the steering arms at the wheels).
Loose steering rack support bushings.
Poor alignment - if the car is jacked before or during the alignment, the alignment is wrong.
Incorrect tire pressures.
Loose front wheel bearings.

Wally Plumley
928 Specialists