[XVar]

I'm replacing my rear suspension with Bilstein B8 shocks and Eibach Pro Kit springs but I'm not sure about the correct bump stops to use. The shocks didn't come with any bump stops so I ordered a set of OEM ones that I'm pretty sure are far too large - they prevent over 50% of the travel distance of the shock.

So my questions are:

a) Are they too large?
b) If so is cutting them shorter a good idea? They seem quite specifically engineered with conical ends - cutting them would remove this at one end - does this matter?
c) Alternatively, are there any suitable stock bump stops from another car that I should use instead?

Photos of the bump stops on the new shocks attached, any advice would be greatly appreciated!

 

[NZ00Z3]

They look like the bump stops for the front shocks. The shaft on the front shocks is thicker than the rears shocks.

The rear shock bump stop is incorporated in the rear springs. Have a look at the top spring rubber pad, there should be a bump stop there. See the attached photo.

 

[XVar]

They're definitely for the rears - see here: http://www.incarmotorfactors.co.uk/...bmw-meyle-dust-cover-kit-rear-3147400002.html

I'm aware of the spring pads/bump stops but don't they serve a different purpose to the bump stops on the shocks? Everything I've read says that Bilstein B6 and B8 rear shocks need bump stops but aren't supplied with them.

Edit: You might be right in that they're the wrong ones (if they're at all needed) as I've found another eBay listing where the same part number isn't marked as suitable for the Z3, only the E36 3-series (which doesn't have the divorced spring setup from the E30 that the Z3 has at the rear).

Can anyone confirm absolutely whether the bump stops are needed or not then?

 

[XVar]

Having looked at the rear suspension exploded diagram on RealOEM it seems there aren't any bump stops listed, just "Stop buffer" (part no.3 on the linked diagram) which looks like a large plastic washer, but there is a dust cover. How does this attach without a bump stop?

http://www.realoem.com/bmw/enUS/showparts?id=CJ32-EUR---Z3-BMW-Z3 2.8&diagId=33_0459#07119905374

 

[vintage42]

I did mine three years ago. I think the stop buffer is the bump stop, is rubber, and it goes under the dust cover. The friction of the tight rubber buffer on the rod is what holds the dust cover up against the upper mount.