Control arm replacement

For the M Powered Z3 derivatives

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Grazza
Joined: Wed 24 Sep, 2014 11:38
Posts: 39

  M roadster S50

Control arm replacement

Post by Grazza » Sat 18 Nov, 2017 18:24

Hi

I'm going through the process of repairing my Z3M and also replacing the suspension all round at the same time.

I had to replace the control arm on the passenger side as it was damaged so thought I would do the same on the drivers side but I'm struggling to get to the nut for the middle ball joint on the drivers side. Even if I manage to get it off I'm even more concerned about getting the new one (lemforder) on as it needs an allen key in the centre of the bolt to lock it whilst you tighten the nut. Does anyone have any advice on this?

Thanks

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Gazza
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Joined: Tue 04 Oct, 2005 21:58
Posts: 9203

  M roadster S54
Location: East London/Essex

Re: Control arm replacement

Post by Gazza » Sat 18 Nov, 2017 20:35

Gazza

"Understeer is when you hit the wall with the front of the car, oversteer is when you hit the wall with the rear of the car. Horsepower is how fast you hit the wall and torque is how far you take the wall with you"

S54 M roadster Image, BMW Z1, BMW M3 CSL, Mustang Fastback

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Grazza
Joined: Wed 24 Sep, 2014 11:38
Posts: 39

  M roadster S50

Re: Control arm replacement

Post by Grazza » Sun 19 Nov, 2017 18:13

Gazza, thanks for the link. I had watched that video and tried in on the passenger side but the bolt was still turning even when I ended up at the point where I was worried about the car coming off the jack stand and given I was underneath trying to do up the bolt I did not feel comfortable continuing.

I have read on a couple of websites that some people disconnect various components in the engine bay to enable access from above but I can't see any way to do this for the drivers side as it doesn't look like there is any space between the engine and the car bodywork (admittedly I was just out doing this in the dark with a torch so I might be mistaken)

The middle ball joint of the control arm bolts onto the Front Axle Support, is there any reason why I can't unbolt and drop this so I can attach the control arms? It looks like all I would need to unbolt in order to do this in addition to the Front Axle Support would be some sort of frame (protecting the bottom of the engine?) unless there is something else attached to the Front Axle support that I can't see (again looking in the dark with a torch so can't be sure)?

Thanks for your help

Del
Joined: Sat 19 Nov, 2011 18:35
Posts: 2122

  Z3 roadster 1.9

Re: Control arm replacement

Post by Del » Mon 20 Nov, 2017 23:07

Are the M ones significantly different from the non-M cars? If so, I apologise. When I changed mine (non M car), I clipped together two 6 inch extensions and a flexi joint and attacked the inner retaining nut (from above) from the engine bay. This set-up gave sufficient "wriggle room" and I know others have used the same tools. Once the nut was removed I separated the arm from below with a "pickle fork" as shown in the video. I was replacing the full arms and bushes so was not worried about damage to the old ones.

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Koolflyer
Joined: Fri 05 Jul, 2013 16:51
Posts: 574

  Z3 roadster 2.8

Re: Control arm replacement

Post by Koolflyer » Tue 21 Nov, 2017 07:46

Like Del mine is a non-M, and I tackled the nut in exactly the same way from above using a combination of extensions etc. It was a bit of a pig but we got it done...note there were two of us! Afterwards I nipped down to my local 'indi' who just double checked the torque for me.
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1997 Z3 2.8 (M52) Roadster Montreal blue
2013 330d (F31) M Sport Alpine White

Grazza
Joined: Wed 24 Sep, 2014 11:38
Posts: 39

  M roadster S50

Re: Control arm replacement

Post by Grazza » Fri 24 Nov, 2017 13:12

Hi, thanks for your replies.

Not sure if the M is different but I can't see anyway of getting to the nut from above on the drivers side (might be possible on the passenger - I can sort of see it) as the engine is right up against the chassis at the point I would need to try and get to the nut. Even if I could get to it the replacement control arm bolt needs an allen key in the top to stop it rotating whilst you tighten the nut so you can't sue a socket set!

Does the idea of removing the front axle support have some issues I am not seeing? It seems relatively simple (he says naively!). I've watched loads of videos, read articles, bought a load of tools (including the pickle fork) and I'm stumped!

Thank for the continued advice.

Juvvajuvva
Joined: Sun 06 Nov, 2016 16:52
Posts: 49

  Z3 roadster 2.8

Re: Control arm replacement

Post by Juvvajuvva » Tue 28 Nov, 2017 23:02

Take the front bumper off and the inner arch liner.Use an Allen key in the Center and a ratchet ring spanner.

Juvvajuvva
Joined: Sun 06 Nov, 2016 16:52
Posts: 49

  Z3 roadster 2.8

Re: Control arm replacement

Post by Juvvajuvva » Tue 28 Nov, 2017 23:07

You can’t just drop the engine support bar off as the engine mounts sit on it. You need to undo them while the engine is supported.
It is way easier to pull the front bumper and arch liner off.
Obviously the front wheel needs to come off too. Drop the front two bolts from the protection cover and the brake ducts.Anything in your way.

PaulI
Joined: Sun 28 Dec, 2003 19:37
Posts: 20

  Z3 roadster 2.8
Location: Weybridge, Surrey

Re: Control arm replacement

Post by PaulI » Wed 29 Nov, 2017 16:03

I'm just about to embark on the same job! I too have got to the point where everything is disconnected, except the central ball joint. This is mainly due to my 22mm socket being just too chunky to fit on the nut with the knuckle joint above it, so I'm in the process of buying a smaller profile socket, and a 22mm ring spanner, and ratchet spanner too. What did you find was the easiest way in the end? Taking the bumper off, does this allow direct horizontal access to the nut? I don't mind taking the bumper off if its the best way!

Juvvajuvva
Joined: Sun 06 Nov, 2016 16:52
Posts: 49

  Z3 roadster 2.8

Re: Control arm replacement

Post by Juvvajuvva » Wed 29 Nov, 2017 20:13

No,
You can't do it with a socket from below the car if the ball joint is spinning . I use a ring spanner in 1/8th turns,ish as it is very confined and an Allen key/tool in the top.
Have you tried applying pressure to the bottom of the ball joint to stop the ball joint spinning?
This negates the need to use the Allen key, but you still need to do it with a ring spanne if you are doing it from under the engine.
I have done loads of them this way.
It is possible with flexy drives if you have them.

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