Z4M Suspension explained

[alexman]

I've owned my Z4M for over 5 years now and other fun cars have come and gone but the M has stayed.

Embarassingly however, I've never taken the opportunity to learn and fully understand how the suspension works (and thus be able to identify when there are issues). I've got a horrible metal clangy sound (when I turn corners mostly) and have identified the steering drop link is a little loose so I'm hoping its that rather than something else (both rear springs have been changed). Its in for Inspection II soon so hopefully this'll be it.

In the meantime, can anyone direct me to a good site/thread that explains in full how the suspension works? (no success via search)

 

[Z4M-2006]

Look up John's (Exdos) posts..

He has done a lot of work on his suspension and has some excellent write ups..

 

[hoffrock]

I have a metallic clatter/jangle sound from the rear when I go over bumps. I inspected all of the suspension and cross braces/exhaust etc. Couldn't find the culprit. I have narrowed it down to the handbrake shoes inside of the rear discs.
I found this out when I jacked it up recently and hit the tire upward with a mallet. It made no noise with the handbrake applied but when I released it and repeated I could hear the clatter.

Will hopefully be fitting a new set of shoes and giving the brakes a service this weekend. Fingers crossed it fixes the problem.

 

[Z4M-2006]

^^^^^^^

You sure its not a snapped coil on off the bottom of the spring? The bottom coil is only small..

Sometimes they are hard to spot ..

 

[hoffrock]

^^^^^^^

You sure its not a snapped coil on off the bottom of the spring? The bottom coil is only small..

Sometimes they are hard to spot ..

100% Not the springs in my case. I had both wheels off and checked the top and bottom of both coils. No small snapped off part, the springs are all there.

 

[Z4M-2006]

I really doubt it will be the shoes.. Unless the retaining clips have come adrift.

Have you checked the rear arm bushes and rose joints?

 

[Diderot]

You mean there's actually suspension? Doesn't feel like most of the time It's the only thing I hate about the car - the ride is brutal.

 

[hoffrock]

Ok so I found the solution to the noise I was having. The previous owners had fitted aftermarket pads, the spring clip on the back of the pad that fits into the piston, was very loose and soft. This meant that the pads were clattering inside the calliper. New pads with sturdy springs sorted the noise right out. Problem solved.