Ratemytopmountwobble.com

[Yeddheng]

When you buy v3's new they come with top mounts.

I’ve gotten to the point where I’ve realised that now, cheers! Disassembled the top of the strut assembly and at first thought that someone had fitted non-M top mounts, but then looked up pics of the V3s and saw that they come with their own hats. I thought the OEM hats were re-used for some reason - perhaps because people have retrofitted the lower part so that they work with adjustable plates?

I’m struggling to find the right replacement part on the KW site, but even if I do I’ll torque up the 22mm nut properly and see if it is actually bearing play before ordering it.

The KW V3 is delivered with some type of "one size fits all BMW" top coil spring perch.
They are 10 mm wider than the original Z4M top mounts, which is important to keep in mind if you intend to order adjustable top mounts.

[BMWZ4MC]

How did the problem manifest itself MrPT?

I have a bit of a front end rattle when going over speed bumps etc and I've been going through the process of checking everything. No noticeable play in any strut brace, suspension or ARB nuts/bolts/links/bushes, but it's all due a refresh anyway. I also found one, partially backed-out engine mount bolt but I don't think that this is contributing to the noise.

Unrelated to the above, I'm replacing the lower spring perch as a few of the plastic tabs had broken off (£30 for a new one!) and I noticed the top hat wobble during disassembly. The 22mm nut seemed tight when I first checked it, but since then I've obtained the proper tools for removing and torquing the nut properly so will re-assemble and check for play again. I suspect someone gave it a few blasts with an impact wrench during installation and it's never been properly tight.

I wonder whether these bearings are "lifetime", from KWs perspective, because it doesn't look as if you can buy replacements on their site. Either that or they only replace them during a refurb. They are properly crimped using proprietary means, so I don't know why I ever thought their replacement would be a DIY job!

Ah ok, thanks. I asked because I’ve suddenly developed a quite marked clunk from the NS front that I can feel transmitted through the steering wheel. The frequency is related to the rate of rotation of the road wheels rather than being associated with vertical movements of the suspension, so I suspect my NS front wheel bearing is rapidly failing. There seems to be slight play and it’s the only remaining original wheel bearing of the four (probably a consequence of lots of track use with semi slick tyres). I haven’t found anything untoward with the track rod or suspension, but given your experience, I should probably have another look.

[bradz]

I do have some ground force top mounts off my V3's that I'll sell if anyone's interested.

[MrPT]

The KW V3 is delivered with some type of "one size fits all BMW" top coil spring perch.
They are 10 mm wider than the original Z4M top mounts, which is important to keep in mind if you intend to order adjustable top mounts.

This.

Spoke to KW support. Turns out the top mounts are supplied to them by Meyle and were originally produced for the E39 5 series. Looking at the part number (31331091709) I think you are right in that different SKUs for the same part appear to be used on a variety of other models.

So the bearings aren’t replaceable but the whole top mount is for about £25. Progress, thanks all...

[BMWZ4MC]

My Zed developed the clunk I described immediately before we went away for Christmas and the New Year, and I didn’t have much time to analyse it before we left. When I got back to Aus last week and drove the car again, it was fairly obvious that the noise was related to suspension travel as much as it was to wheel rotation. I don’t have many tools in Sydney at the moment (they’re somewhere in the Red Sea on a container ship) so I took it to a well-recommended BMW Indy. Happily, he happens to run KW Clubsports on his E46 M3 race car, so he has a fair bit of experience with them. When he removed the damper, he found the source of the clunk to be exactly the same as with yours MrPT. In his opinion, it probably wasn’t assembled correctly and once he’d torqued it up to spec, the problem had gone

[MrPT]

When he removed the damper, he found the source of the clunk to be exactly the same as with yours MrPT. In his opinion, it probably wasn’t assembled correctly and once he’d torqued it up to spec, the problem had gone

Interesting. Seems to be quite a common story for KW V3s (albeit with only a few examples from Z4 Land). Installers probably just hit the nut with an impact gun and the spring tension holds everything in place, despite the nut being under-torqued.

I've installed the new top mount, correctly torquing with the spring under zero compression and there is no play in the assembly now. The only snag was that the current Meyle part has a smaller opening in the top around the nut that the original, so I had to grind down the injector socket outer surface by about 1 mm.

For reference the shocks are ~25k miles old. One degree of movement over 50cm is 0.9cm, so I think these bearings are probably worth replacing before they start making noises.