Symptoms of bad thurst arms/lower control arms?

sprp85 · 06-04-2018, 04:05 PM

Hey all,

I did search a bit to find indefinite answer on the question of "what are the symptoms of bad thrust arms and lower control arms"

Recently my car developed this odd clunking noise at low speed. It is definitely coming from front of the car whenever I go over a small imperfections on the road, say, joints in parking garages and short, sharp bumps.

Before this odd noise developed, B12 kit along with all brand new hardwares were installed. Since the install (8k miles), it has been dead quite until recently.

When this knocking occurs, I can actually feel it on the pedal and what not, a gentle thud.

So I did check up on end links that were replaced a few months ago and they were on tight with no plays.

So my next target to check out was front control arms. I did not see visible leakage when I checked on it but it does twist with moderate force.

Given that the arms have 108k miles on them....

I do have a set of M3 arms sitting and waiting but wanted to go over what is really causing this issue at the moment, thus I can get it fixed while I do the arms.

So in short, do bad arms cause physically feel-able knock/thud along with audible knocking?

Thank you in advance!

Wolf 335 · 06-04-2018, 04:20 PM

Clunk is likely related to a ball joint.

Bad thrust arm bushings will give you a shake in the steering wheel when you are driving between 80-100km/h or braking in that speed range as well.

Jack the car, grab the wheel at 3 and 9 and push side to side and do the same at 12 and 6 position. Feel for play and listen for noise. If you could have a friend to the pushing and you place your hand on the ball joints at the steering knuckle to feel for movement, it would be a lot easier.

sprp85 · 06-06-2018, 09:44 AM

Both thrust arms and Lower control arm have ball joints at the ends also I assume?

Wolf 335 · 06-06-2018, 11:35 AM

Quote:

Originally Posted by sprp85

Both thrust arms and Lower control arm have ball joints at the ends also I assume?

Yes, ball joint attaches to the wheel carrier, bushings attach to the body frame

sprp85 · 06-06-2018, 05:24 PM

Thank you for confirmation!

JUMAS · 06-06-2018, 07:29 PM

I had a clunk in my front suspension, ended up being a control arm that was not torqued to spec. tightened it, fixed it.

06-04-2018, 04:05 PM	#1
sprp85 Lieutenant 98 Rep 406 Posts Drives: S54/N52 Join Date: May 2014 Location: MA iTrader: (3) Garage List 2006 E46 M3 [0.00] 2007 E91 328i [0.00]	Symptoms of bad thurst arms/lower control arms? Hey all, I did search a bit to find indefinite answer on the question of "what are the symptoms of bad thrust arms and lower control arms" Recently my car developed this odd clunking noise at low speed. It is definitely coming from front of the car whenever I go over a small imperfections on the road, say, joints in parking garages and short, sharp bumps. Before this odd noise developed, B12 kit along with all brand new hardwares were installed. Since the install (8k miles), it has been dead quite until recently. When this knocking occurs, I can actually feel it on the pedal and what not, a gentle thud. So I did check up on end links that were replaced a few months ago and they were on tight with no plays. So my next target to check out was front control arms. I did not see visible leakage when I checked on it but it does twist with moderate force. Given that the arms have 108k miles on them.... I do have a set of M3 arms sitting and waiting but wanted to go over what is really causing this issue at the moment, thus I can get it fixed while I do the arms. So in short, do bad arms cause physically feel-able knock/thud along with audible knocking? Thank you in advance!
	Appreciate 0 Tweet Quote

06-04-2018, 04:20 PM	#2
Wolf 335 Brigadier General 2565 Rep 3,663 Posts Drives: 2007 E92 335i Join Date: Aug 2012 Location: Toronto iTrader: (0)	Clunk is likely related to a ball joint. Bad thrust arm bushings will give you a shake in the steering wheel when you are driving between 80-100km/h or braking in that speed range as well. Jack the car, grab the wheel at 3 and 9 and push side to side and do the same at 12 and 6 position. Feel for play and listen for noise. If you could have a friend to the pushing and you place your hand on the ball joints at the steering knuckle to feel for movement, it would be a lot easier. Last edited by Wolf 335; 06-04-2018 at 04:26 PM..
	Appreciate 1 sprp8598.00 Quote

06-06-2018, 09:44 AM	#3
sprp85 Lieutenant 98 Rep 406 Posts Drives: S54/N52 Join Date: May 2014 Location: MA iTrader: (3) Garage List 2006 E46 M3 [0.00] 2007 E91 328i [0.00]	Both thrust arms and Lower control arm have ball joints at the ends also I assume?
	Appreciate 0 Quote

06-06-2018, 05:24 PM	#5
sprp85 Lieutenant 98 Rep 406 Posts Drives: S54/N52 Join Date: May 2014 Location: MA iTrader: (3) Garage List 2006 E46 M3 [0.00] 2007 E91 328i [0.00]	Thank you for confirmation!
	Appreciate 0 Quote

06-06-2018, 07:29 PM	#6
JUMAS Private First Class 39 Rep 161 Posts Drives: 2011 335i Join Date: Mar 2018 Location: Tampa iTrader: (0)	I had a clunk in my front suspension, ended up being a control arm that was not torqued to spec. tightened it, fixed it.
	Appreciate 0 Quote