Help needed: DIYing my Tension Struts (control arms) this weekend, questions

james0013 · 03-11-2015, 11:29 PM

Hi all
I am going to DIY my upper control arms (aka the tension arm) bushings. (I am really repplacing the whole control arms as I could not find a shop to press out the old bushing and push in the new one.

I do not have a lift and plan to follow the directions that say "snug busing through bolt but do not torque yet. Replace wheel, place car on ramps and torque busing bolt to spec with suspension under load.

My question is how can I be sure this will give the correct ride height using this method?

Is the ride height governed by the strut and not the bushing?

What will prevent the suspension from collapsing if the bolt on the tension strut is not at the correct torque spec?

I have read the following:
rmEuropean DIY
http://www.rmeuropean.com/bmw-e90-Co...placement.aspx
Bavauto video:

X_Drive · 03-12-2015, 01:08 AM

To answer your questions:

1. I am not an advocate of "snugging," bolts for bushings then torquing them. I leave them loose enough that the bolt itself can still spin when using a wrench. But not so loose that the arm is still flopping around in the mount. This ensures me 100% that I am not in any way subjecting the bushing to any loading when positioning the arm before final assembly. The best way and most safe way to ensure proper ride height is to torque the bolts when the car is completely flat on a level surface, such as an alignment hoist. 2nd best way is to jack up the suspension, as in the video, until the suspension cannot be raised anymore and is now acting against the vehicle. This also mimics the suspension to be in the most laden position. Just be sure that all your equipment is in quality working condition and that you are completely safe. So if you are doing this on your back on the garage floor with jack stands and a jack, place your rims under your car as a "plan b," so you do not end up a safety commercial.

2. Suspension height is mainly governed by the springs, however can be influenced by other suspension components. (i.e. lowering arms, spring mounts damaged/worn components)

3. If you by chance have a bolt break and when I mean break, I mean a full sheering of the bolt, not much other than your wheel and tire slamming into your chassis will stop the suspension from full collapse. If you get to that point then you would already have begun the start of a bad day. However, if the nut and bolt loosens, then the bolt will still connect the arm at the subframe mount and no collapse should occur. Lots of noises though. I personally wouldn't drive very far if that happens.

HTH

hockeyplayer · 03-12-2015, 08:23 AM

OP, you're going in the right direction. This is actually a pretty easy job so don't stress too much over it. I used this Pelican article as a guide: http://www.pelicanparts.com/BMW/tech...eplacement.htm

The biggest PITA of the job was taking off/on the plastic undercarriage. Other than that it went very smoothly. To answer one of your questions...I was never concerned about ride height. I believe that would be more of a concern if you were doing springs/struts.

Good luck!

All4bigAl · 03-12-2015, 08:31 AM

I just had my bushings pressed out yesterday by a local mechanic. Bushings and bolts were $120 and I paid $130 to have them installed, which included a free alignment check. I'm sure if you ask around someone will press them in for you if you wanted to go that route. Nothing wrong with replacing the whole control arm either, though. It would make sense that if the bushing was failing the ball joint wouldn't be too far behind.

Good luck!! You will love how much better your suspension feels!

avocet · 03-12-2015, 08:31 AM

the ride height will only change if you tighten the bolts in a 'loaded' position. lowering the car onto the wheels before tightening puts the bushings into a 'neutral' position. if you tighten them while the car is raised, the bushings will want to spring back to the the position they were tightened at once the car is lowered.

if the bolt is snugged but not tightened nothing will collapse. that bolt will be essentially under a shear load, and tightening it will have no effect on its ability to hold your car up.

mojobmw_e90 · 03-12-2015, 08:44 AM

Quote:

Originally Posted by avocet

the ride height will only change if you tighten the bolts in a 'loaded' position. lowering the car onto the wheels before tightening puts the bushings into a 'neutral' position. if you tighten them while the car is raised, the bushings will want to spring back to the the position they were tightened at once the car is lowered.

if the bolt is snugged but not tightened nothing will collapse. that bolt will be essentially under a shear load, and tightening it will have no effect on its ability to hold your car up.

I did my m3 front end over the weekend and tightend everything while the car was raised. Is this not the correct way of doing it? I pre-installed everything and lightly tightened all the bolts until everything was done, than went again and trq everything.. No weird issues or noise at the moment

doogee · 03-12-2015, 09:11 AM

Both sides of the suspension MUST be compressed before you tighten down the bolts unless you want to destroy your brand new bushings.

mojobmw_e90 · 03-12-2015, 09:14 AM

Quote:

Originally Posted by doogee

Both sides of the suspension MUST be compressed before you tighten down the bolts unless you want to destroy your brand new bushings.

Guess il have to lift it up, loosen them and redo it with a jack under the rotor to compress it.

hockeyplayer · 03-12-2015, 09:34 AM

Quote:

Originally Posted by mojobmw_e90

Guess il have to lift it up, loosen them and redo it with a jack under the rotor to compress it.

Yes, I just used a floor jack underneath the entire rotor/knuckle and just jacked it up until it was beginning to lift off the jack stand. Then I tightened it down to spec.

I'm not sure what the other comment regarding "both" sides meant...I just did each side individually.

james0013 · 03-16-2015, 12:34 AM

Hi all,

Today I DIYed the control arms, all in all it was a time consuming but simple job.

Where I am stuck is torquing the nut on the end of the ball joint to spec. The left one was fine. However the right hand side is somehow deformed and I can not get the T44 Torx bit into the end of the spindle. The end result is that the nut has gone one so far but I can not torque it to spec (and as luck would have it I can not remove the nut either)

The one on the left is the problematic right side ball joint, the right is the left side ball joint with the nice T45 star in it. It looks like someone has tried to drill out the end of the spindle at some point. God knows why

I am considering drilling and opposite threading a screw or something into the end of the spindle so I can count hold it but I am not sure what that would do it the strength of the ball joint.

Anyone got ant suggestions?

HELP

doogee · 03-16-2015, 07:41 AM

Some clown probably used an air chisel to break it loose at one point.

Get your socket and try to hammer it in, it should break through the metal.

james0013 · 03-16-2015, 02:56 PM

Quote:

Originally Posted by doogee

Some clown probably used an air chisel to break it loose at one point.

Get your socket and try to hammer it in, it should break through the metal.

I am not sure I am ready to start beating on this with a hammer yet, but I see where you are going. Sadly there seems to be a huge size differential between be size of the T40 torx and the remainder of the whole.

It occurred to me that once compressed the ball joint will no longer spin. So if I can use something to compress it enough I can tighten the nut. I was thinking a large pair of channel lock pliers or using a ball joint separator in reverse (people have had success with this or be it on Hondas)

james0013 · 03-18-2015, 04:51 PM

In the end I chickened out and took the car to a local (less than a mile from my house) garage who put in the nut with an air gun.

03-11-2015, 11:29 PM	#1
james0013 Private 13 Rep 59 Posts Drives: 2008 328 X1 Join Date: Mar 2013 Location: Seattle, WA iTrader: (0)	Help needed: DIYing my Tension Struts (control arms) this weekend, questions Hi all I am going to DIY my upper control arms (aka the tension arm) bushings. (I am really repplacing the whole control arms as I could not find a shop to press out the old bushing and push in the new one. I do not have a lift and plan to follow the directions that say "snug busing through bolt but do not torque yet. Replace wheel, place car on ramps and torque busing bolt to spec with suspension under load. My question is how can I be sure this will give the correct ride height using this method? Is the ride height governed by the strut and not the bushing? What will prevent the suspension from collapsing if the bolt on the tension strut is not at the correct torque spec? I have read the following: rmEuropean DIY http://www.rmeuropean.com/bmw-e90-Co...placement.aspx Bavauto video:
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03-12-2015, 01:08 AM	#2
X_Drive Second Lieutenant 8 Rep 263 Posts Drives: E46, E91, F21 Join Date: Apr 2014 Location: Northwest iTrader: (0) Garage List 2017 M140i LCI [0.00] 2005 E46 325xi [0.00] 2011 E91 328i xDriv ... [0.00]	To answer your questions: 1. I am not an advocate of "snugging," bolts for bushings then torquing them. I leave them loose enough that the bolt itself can still spin when using a wrench. But not so loose that the arm is still flopping around in the mount. This ensures me 100% that I am not in any way subjecting the bushing to any loading when positioning the arm before final assembly. The best way and most safe way to ensure proper ride height is to torque the bolts when the car is completely flat on a level surface, such as an alignment hoist. 2nd best way is to jack up the suspension, as in the video, until the suspension cannot be raised anymore and is now acting against the vehicle. This also mimics the suspension to be in the most laden position. Just be sure that all your equipment is in quality working condition and that you are completely safe. So if you are doing this on your back on the garage floor with jack stands and a jack, place your rims under your car as a "plan b," so you do not end up a safety commercial. 2. Suspension height is mainly governed by the springs, however can be influenced by other suspension components. (i.e. lowering arms, spring mounts damaged/worn components) 3. If you by chance have a bolt break and when I mean break, I mean a full sheering of the bolt, not much other than your wheel and tire slamming into your chassis will stop the suspension from full collapse. If you get to that point then you would already have begun the start of a bad day. However, if the nut and bolt loosens, then the bolt will still connect the arm at the subframe mount and no collapse should occur. Lots of noises though. I personally wouldn't drive very far if that happens. HTH
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03-12-2015, 08:23 AM	#3
hockeyplayer Captain 74 Rep 776 Posts Drives: 2006 325i, 2006 325xi Join Date: Oct 2011 Location: NC iTrader: (0)	OP, you're going in the right direction. This is actually a pretty easy job so don't stress too much over it. I used this Pelican article as a guide: http://www.pelicanparts.com/BMW/tech...eplacement.htm The biggest PITA of the job was taking off/on the plastic undercarriage. Other than that it went very smoothly. To answer one of your questions...I was never concerned about ride height. I believe that would be more of a concern if you were doing springs/struts. Good luck!
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03-12-2015, 08:31 AM	#4
All4bigAl Private 6 Rep 63 Posts Drives: E93 M3, F10 550, E70 X5 Join Date: Sep 2014 Location: Wisconsin iTrader: (1)	I just had my bushings pressed out yesterday by a local mechanic. Bushings and bolts were $120 and I paid $130 to have them installed, which included a free alignment check. I'm sure if you ask around someone will press them in for you if you wanted to go that route. Nothing wrong with replacing the whole control arm either, though. It would make sense that if the bushing was failing the ball joint wouldn't be too far behind. Good luck!! You will love how much better your suspension feels!
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03-12-2015, 08:31 AM	#5
avocet Major 252 Rep 1,157 Posts Drives: 2007 328i 2011 X5d Join Date: Sep 2010 Location: Vancouver bc iTrader: (0)	the ride height will only change if you tighten the bolts in a 'loaded' position. lowering the car onto the wheels before tightening puts the bushings into a 'neutral' position. if you tighten them while the car is raised, the bushings will want to spring back to the the position they were tightened at once the car is lowered. if the bolt is snugged but not tightened nothing will collapse. that bolt will be essentially under a shear load, and tightening it will have no effect on its ability to hold your car up.
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03-12-2015, 09:11 AM	#7
doogee Major 748 Rep 1,256 Posts Drives: '08 M3, '09 328xi Sport Wagon Join Date: Oct 2008 Location: Ancaster, ON, Canada iTrader: (0)	Both sides of the suspension MUST be compressed before you tighten down the bolts unless you want to destroy your brand new bushings.
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03-16-2015, 12:34 AM	#10
james0013 Private 13 Rep 59 Posts Drives: 2008 328 X1 Join Date: Mar 2013 Location: Seattle, WA iTrader: (0)	Damaged ball joint can not counter hold to tighten nut to Spec Hi all, Today I DIYed the control arms, all in all it was a time consuming but simple job. Where I am stuck is torquing the nut on the end of the ball joint to spec. The left one was fine. However the right hand side is somehow deformed and I can not get the T44 Torx bit into the end of the spindle. The end result is that the nut has gone one so far but I can not torque it to spec (and as luck would have it I can not remove the nut either) The one on the left is the problematic right side ball joint, the right is the left side ball joint with the nice T45 star in it. It looks like someone has tried to drill out the end of the spindle at some point. God knows why I am considering drilling and opposite threading a screw or something into the end of the spindle so I can count hold it but I am not sure what that would do it the strength of the ball joint. Anyone got ant suggestions? HELP Attached Images
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03-16-2015, 07:41 AM	#11
doogee Major 748 Rep 1,256 Posts Drives: '08 M3, '09 328xi Sport Wagon Join Date: Oct 2008 Location: Ancaster, ON, Canada iTrader: (0)	Some clown probably used an air chisel to break it loose at one point. Get your socket and try to hammer it in, it should break through the metal.
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03-18-2015, 04:51 PM	#13
james0013 Private 13 Rep 59 Posts Drives: 2008 328 X1 Join Date: Mar 2013 Location: Seattle, WA iTrader: (0)	chickened out In the end I chickened out and took the car to a local (less than a mile from my house) garage who put in the nut with an air gun.
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