Correct bump stops for 2003 M-sport II with Bilstein B8 Struts

[Jay M.]

Hi all,

I'm in the midst of installing Bilstein B8 struts and the H&R sport springs all around in my 2003 540i M sport. I bought new strut mounts, spring pads, and front bearings to compete the install. I planned to re use the original boots and bump stops. This was no problem in the rear. When I removed the front struts (Also old Bilstein B8s, Part number 35-114093), I was troubled to find no bump stops installed by the previous owner.

Bilstein says to use the OEM bump stops with no modification for this part number. This M Sport II suspension is challenging to find a parts list for, but after some searching of build lists (and seeing as these B8s are M5/540 compatible) I ordered the 31332226674 M5 Front bump stop.

Needless to say I'm writing this post and the parts don't fit. Specifically, the inner diameter of the bump stop (30mm) does not come close to during over the large diameter stanchion of the B8 strut (40mm). The bump stop only fits on the 16mm upper spindle, and installing it here means I need to compress the bump stop, not the spring, in order to install the upper strut components. There is no way that's correct, and I have no good way to do this without compressing the damper.

To the folks on here running Bilstein B8s (PN 35-114093) with or without H&R sport springs (50464), what bump stops are you running? It seems the previous owner encountered the same problem I have and just decided not to run bump stops altogether. Trying to get some advice before cutting these parts a larger inner diameter, or ordering a different stop. Thanks for your help guys!

Edit: See image of front strut with M5 bump stop. Note large diameter stanchion prevents further install of the bump stop. I cannot install the upper strut hardware with the stop in this position.

DD421C97-E8ED-46F2-B14C-114A85B074D2.jpg

[RosieE39]

B6’s and B8’s have internal bump stops so external ones are not needed or necessary.
That’s also why the dust boot covers the complete shock shaft.

[balidawg]

I’m just about to install B8 struts and Eibach springs front and rear and didn’t order bump stops yet.
Glad I just happened to read this thread!