M3 control arm install HELP!! Which arm goes where (rears)?

Mr Black · 08-09-2014, 07:32 PM

Had to add "rears" in the title so nobody thinks I'm REALLY dumb....

I have the full rear M3 control arm conversion kit from ECS....was pretty sure I got the part numbers right but when I started installing it things looked odd. Cross-referenced the part numbers stamped right on the arms with those on the invoice/shipping list, and in theory I have the correct arms on the correct side. Does this look right? Shorter arm is curved with the ends upwards from the ground, longer arm curved downward (opposite).

This is the LEFT side jftr.....

Anyways, whether this is correct or not, I have run into a major install issue- the outboard (knuckle) ends of both arms have been a real bear to get fastened on because the arms are not aligned with the mounting holes on the knuckle. The longer one I wrestled into place and the bolt went in fairly easily, but I've now stripped the mounting hole on the knuckle where the shorter arm (guide rod?) attaches.

I've added lines to illustrate the misalignment issue. Maybe I was impatient and should have jacked the wheel assembly upwards and the alignment would have straightened itself out?

Anyways I may have to go to a shop to get this side remedied, but I want to make sure I at least have the parts on the right side for when I attempt to do the other side tomorrow. Also, any tips on how to get the suckers bolted up without running into this issue again and ruining another knuckle would be appreciated!

andrey_gta · 08-09-2014, 09:28 PM

The //M logo letter should be right side up. But since you have TRW arms this looks correct

The long arms is curving down and the red and yellow lines are correct. Black Dot on arm means left side, the other side has a Blue X

You may need to loosen the shock carrier arm @ knuckle to pop it in or even at Subframe. I had your issue too, but my car had no shocks and springs to stop my mobility to wiggle

The top short arm curves up and also may need a wiggle to pop into the socket at knuckle

Just noticed see if you can attach the brake sensor line to the opposite side, closer to shock

You will need an alignment

CALWATERBOY · 08-10-2014, 12:24 AM

.

Dude!

HERE

Mine:

Mr Black · 08-10-2014, 09:20 AM

Thx Waterboy....I've seen your post but it wasn't fully obvious from the angle of that photo. Your link makes it pretty clear.

08-09-2014, 07:32 PM	#1
Mr Black Enlisted Member 3 Rep 34 Posts Drives: 2009 335i 6MT Join Date: Aug 2012 Location: Northern Canadia iTrader: (1)	M3 control arm install HELP!! Which arm goes where (rears)? Had to add "rears" in the title so nobody thinks I'm REALLY dumb.... I have the full rear M3 control arm conversion kit from ECS....was pretty sure I got the part numbers right but when I started installing it things looked odd. Cross-referenced the part numbers stamped right on the arms with those on the invoice/shipping list, and in theory I have the correct arms on the correct side. Does this look right? Shorter arm is curved with the ends upwards from the ground, longer arm curved downward (opposite). This is the LEFT side jftr..... Anyways, whether this is correct or not, I have run into a major install issue- the outboard (knuckle) ends of both arms have been a real bear to get fastened on because the arms are not aligned with the mounting holes on the knuckle. The longer one I wrestled into place and the bolt went in fairly easily, but I've now stripped the mounting hole on the knuckle where the shorter arm (guide rod?) attaches. I've added lines to illustrate the misalignment issue. Maybe I was impatient and should have jacked the wheel assembly upwards and the alignment would have straightened itself out? Anyways I may have to go to a shop to get this side remedied, but I want to make sure I at least have the parts on the right side for when I attempt to do the other side tomorrow. Also, any tips on how to get the suckers bolted up without running into this issue again and ruining another knuckle would be appreciated! Last edited by Mr Black; 08-09-2014 at 07:38 PM..
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08-09-2014, 09:28 PM	#2
andrey_gta Brigadier General 318 Rep 4,040 Posts Drives: 130i coupé ;) Join Date: Nov 2011 Location: Bimmerpost iTrader: (1) Garage List 2008 BMW 128i [10.00]	The //M logo letter should be right side up. But since you have TRW arms this looks correct The long arms is curving down and the red and yellow lines are correct. Black Dot on arm means left side, the other side has a Blue X You may need to loosen the shock carrier arm @ knuckle to pop it in or even at Subframe. I had your issue too, but my car had no shocks and springs to stop my mobility to wiggle The top short arm curves up and also may need a wiggle to pop into the socket at knuckle Just noticed see if you can attach the brake sensor line to the opposite side, closer to shock You will need an alignment __________________ 128i Sport 6MT converted to Euro 130i spec, 3.73 diff, tuned by evolve ~220 whp 207 wtq(ft-lb) SAE In-progress: //M front arm, M3 rack, e36M lip Wishlist: Coils, n55 mnts, headers, LSD, e60 finn diff "The 1-series is the last car that BMW engineered before the Germans, as a car-making culture, fell out of love with driving." - R&T 2013 135is
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08-10-2014, 12:24 AM	#3
CALWATERBOY Major 150 Rep 1,160 Posts Drives: 2009 E93 N54 Join Date: Jan 2011 Location: San Francisco iTrader: (0)	. Dude! HERE Mine:
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08-10-2014, 09:20 AM	#4
Mr Black Enlisted Member 3 Rep 34 Posts Drives: 2009 335i 6MT Join Date: Aug 2012 Location: Northern Canadia iTrader: (1)	Thx Waterboy....I've seen your post but it wasn't fully obvious from the angle of that photo. Your link makes it pretty clear.
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