55-60mph shimmy

[Scott C]

One last source of shimmy folks and it is too bad it took me so long to figure it out.... (Refer to my post last year on all the parts i replaced).

The Caliper pistons were sticking... I had not replaced or rebuilt them because they seemed okay but in fact were not. (I had cleaned the slider pins - they were perfectly fine). So lesson learned. I should mention that the vibration caused by the front brakes felt "very" alive and harsh (high frequency) and was clearly noted in the steering wheel. I also need to mention that the brakes when applied were smooth so it was a pad skipping (with no brake pedal force applied) that caused this vibration as best I can tell AND it was intermittant!.

Secondly, after the replacement, I then drove the car over the winter and sure enough the vibration came back (this was after I replaced the calipers). I took the brakes off and found the "new" sliders were rusted to crap. I polished the 15 year old originals, put them in and smooth as silk now.

The only vibration i have now is from 48-53 mph and it is from the drive shaft (rebuilt and I have tried multiple times to align it better and have adjusted the center bearing every which way from Sunday). It is very small in amplitude is not present at any other speed. I can definitely live with this...

Cheers!

Scott
(and my desire to get a 2005 BMW 525 is waning now)