Xoutpost.com - Shimmy, shimmy ko ko bop ...

About 8 months ago I replaced both outer CV joint boots on our 2001 X4 4.4 w/sport package – thanks to the X5world article by “hayaku” the boot R&R was reasonably easy. I also under the heading of "PM" replaced the tension struts, ball joints, wishbones, anti-roll bar links and tie rods with parts bought as a kit. The job was finished with a dealer wheel alignment.

2 months ago in a span of about 100 miles the truck developed a severe "road induced" steering wheel “shimmy” between 40 and 55 mph and for the first time there was brake “judder” when stopping. In an attempt to fix the shimmy/judder problem the front tires were spin balanced and checked for run-out (no help) followed by new Pirelli Scorpion tires with a Hunter road force balance (significant reduction in shimmy but the issue was still present).

I decided to R&R the tension struts and with the help of our friends at Morristown BWM a set arrived promptly )and at lower cost than catalog replacements). I pulled the right tension strut first and found that the “almost new” ball joint was “looser than a Goose” – with at least 1/8” of axial free play. Gen BMW ball joints were obtained and both the right and left side components were replaced. The result: no shimmy and no judder.

My advise from all of this … buy gen BMW parts – I didn’t and paid for my mistake. Upon reflection I realized that some of the parts in the front suspension kit were “name” brands but some – ie. the ball joints – had no identification of origin. Also, if you have a shimmy/judder issue replace both the tension strut and ball joint - remove the strut and ball joint as an assembly and you don’t have to worry about a “separator” tool.

A note on ball joints:

The installation torque is 45 lb-ft for the two mounting screws and 60 lb-ft for the nut that joins the ball joint to the strut. BTW it appears that BMW fastener installation torque specs in the “TIS” are “dry” – no oil.

On my 2001 X5 the OEM mounting screw had a “male” Torx head and removal was accomplished with an E12 Torx socket. The gen BMW replacement screws have a “female” button head that takes a T50 socket – use 3/8” drive tools and you won't have a problem accessing the screws with the brake dust shield in place.

Cheers,
Gary Hansen