Right fellas, as everyone knows, http://bigcoupe.com/phpBB2/viewtopic.php?t=1967&start=30 - my Six is having M635CSi suspension installed   

As of tonight, it looks like the mechanic (a serving BMW technician) has hit a problem.  

Basically, almost all the M635CSi suspension kit is now installed on my car (a standard '83 635CSi) - springs, dampers, top mounts, bump stops,  bushes, pads, etc., plus the 750iL upper control arm bushes. All of that went in OK.

BUT:

Mechanic reports that the anti-roll bars from the dismantled M635CSi do not fit. Apparently the front one in particular (25mm dia) rubs the subframe. This is the first I've heard of this happening, as no one else who has done this conversion has reported this problem. M6s and standard Sixes (from May 1982) used the same subframe.

For the moment, he has put back the original 19mm front/14mm rear and is going to take it for a test run, and will then investigate the parts database to see if anything changed.

I'm surprised, though.

So what might be causing this? Any ideas?

And what might I usefully do to get round the problem?

As far as I can make out you have to change the mounting bracket for the two bolt type as fitted to the M535 E28 chassis. If not the stronger 25mm bar will rip of the 6 series one bolt fitting. This requires welding a new bracket on .  Aslo check the mounted on the shocker if you intend to try the 25mm bar.

Give me a call if I can be of any futher help.

Regards

RossM6/635 wrote: As far as I can make out you have to change the mounting bracket for the two bolt type as fitted to the M535 E28 chassis. If not the stronger 25mm bar will rip of the 6 series one bolt fitting. This requires welding a new bracket on .  Aslo check the mounted on the shocker if you intend to try the 25mm bar.

Right so, this is what it looks like underneath the M635CSi at the front:

The new brackets and bushes I have are the M635CSi ones. Ross, are you saying I should have bought E28 M535i ones instead?

The parts diagram:

is unhelpful because it gives the same generic diagram, whether or not you have E24 635CSi or M635CSi, or E28 M535i or M5

RossM6/635 wrote: Give me a call if I can be of any further help.

I'd do this, but I've mislaid your mobile number

In the end, I went back to the standard Six roll bars for the time being....

...the car's now back, and things are a LOT firmer  ; even so, although it sits lower, and it feels like you're driving by the seat of your underpants, it's not that much lower.

Meanwhile, this is what happens to suspension that's expected to work for 20 years or more: