This is a common problem for all BMW AWD/4WD vehicles which are designated an X in their title(For example: X3, X5, 325Xi). The front axles on these vehicles are under extra stress as they not only have to flex left and right (to facilitate steering) but also turn spin around as power is directed to the wheel when being driven. As a result, time and road conditions take their toll more quickly and the deteriorating rubber boot eventually tears. Once this occurs, the grease within the boot, intended to lubricate the “CV” joint, leaks out. Once all of the grease has leaked out, the joint will become stiff causing extensive damage to all surrounding parts and can result in the need for the entire axle and shaft to be replaced.
In addition to the damage to various parts, there is a possibility that axle grease could leak onto the inner part of the wheel, and possibly the brake rotor resulting in a significant increase in stopping distance.
To avoid costly repairs, we recommend periodic inspections to ensure that your font axle boot is intact.
An axle boot replacement with using genuine factory BMW parts, cleaning and repacking of joints costs $350 for parts and labor.
On the other hand, a replacement axle alone costs around $500 just for the parts!
That being said, some opt for replacing worn axle boots with generic, non-BMW factory parts. We have found that generic axle boots and parts tend to be of inferior build quality and last only half as long as a genuine BMW part. At BimmerPhD we not only use the original parts, but our BMW factory trained master technicians also use a special factory removal/installation tool that ensures the job gets done correctly and to factory specs.
Lately in our shop we’ve seen the results of other so called “German shops” who execute this job without the correct tools and instead pound the axle boot off and on with hammers and chisels. We invite you to save money and future headaches and bring your car to the pro’s here at Bimmer PhD.