Lowering the car and bushings

jwzimm · 11-25-2013, 07:00 PM

Hey everyone,

I have been doing my research in prep for installing coilovers on my car and I have come across something interesting. I noted in the ECS tuning video (

) they note you need to loosen the bolt for the control arm bushing and then tighten it with the suspension loaded. I wonder if folks here know this.

It actually makes a lot of sense. These bushings are trapped when the bolts are tight and are not allowed to rotate with the suspension as it travels. This isn't normally a big deal as they are set with the suspension loaded at the factory and the deflection isn't too much depending on vehicle load out. When the car is lowered you have effectively changed the unladen loaded ride height of the car. If these bushings are not reset to this ride height they will be constantly preloaded. This can lead to premature wear and ride harshness.

The task is a little difficult to do but it is very important I think. You basically have to get the car up on ramps once you have set your ride height. You then get under the car and loosen and then retorque the bolts for the suspension pieces with bushings in them to reset them.

Anyone care to comment? I know I will be doing this during my install for sure! I believe this needs to be done on both the control arm and the toe arm but I will verify when I am under the car.

ajsalida · 11-25-2013, 07:40 PM

Yes it is very important. Some folks call this indexing the bushings. People who assemble suspensions and tighten everything with wheels hanging in the air wonder why they don't go as low as they want or can't hit alignment specs or other bad things that happen eventually.

jwzimm · 11-25-2013, 07:43 PM

It is interesting how little it is mentioned in the DIYs then. I am debating doing a full DIY while I install my coils. Shouldn't be too hard. Just have to remember to take photos along the way.

Hops128i · 11-25-2013, 08:53 PM

http://blog.bavauto.com/14344/

I used this video to install camber plates, very detailed.

jwzimm · 11-25-2013, 09:23 PM

Thanks for the link. I think the ECS Tuning video is more applicable though as I will be doing a full coilover setup.

The main point I am making in this thread is that the bushings need to be re-indexed when you install lowering springs or a coilover system.

edirtaynine · 11-25-2013, 11:22 PM

i always do that to my suspension installs after my friend taught me it

11-25-2013, 07:00 PM	#1
jwzimm Colonel 692 Rep 2,770 Posts Drives: '16 M3 Join Date: Jun 2011 Location: Renton, WA iTrader: (17)	Lowering the car and bushings Hey everyone, I have been doing my research in prep for installing coilovers on my car and I have come across something interesting. I noted in the ECS tuning video ( ) they note you need to loosen the bolt for the control arm bushing and then tighten it with the suspension loaded. I wonder if folks here know this. It actually makes a lot of sense. These bushings are trapped when the bolts are tight and are not allowed to rotate with the suspension as it travels. This isn't normally a big deal as they are set with the suspension loaded at the factory and the deflection isn't too much depending on vehicle load out. When the car is lowered you have effectively changed the unladen loaded ride height of the car. If these bushings are not reset to this ride height they will be constantly preloaded. This can lead to premature wear and ride harshness. The task is a little difficult to do but it is very important I think. You basically have to get the car up on ramps once you have set your ride height. You then get under the car and loosen and then retorque the bolts for the suspension pieces with bushings in them to reset them. Anyone care to comment? I know I will be doing this during my install for sure! I believe this needs to be done on both the control arm and the toe arm but I will verify when I am under the car.
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11-25-2013, 07:40 PM	#2
ajsalida Colonel 229 Rep 2,387 Posts Drives: 95 M3, 02 R1150GSA, 09 335xi Join Date: Aug 2010 Location: SW USA iTrader: (2)	Yes it is very important. Some folks call this indexing the bushings. People who assemble suspensions and tighten everything with wheels hanging in the air wonder why they don't go as low as they want or can't hit alignment specs or other bad things that happen eventually.
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11-25-2013, 07:43 PM	#3
jwzimm Colonel 692 Rep 2,770 Posts Drives: '16 M3 Join Date: Jun 2011 Location: Renton, WA iTrader: (17)	It is interesting how little it is mentioned in the DIYs then. I am debating doing a full DIY while I install my coils. Shouldn't be too hard. Just have to remember to take photos along the way.
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11-25-2013, 08:53 PM	#4
Hops128i Captain 74 Rep 675 Posts Drives: 2010 128i, manual, sport pkg Join Date: Aug 2010 Location: Silver Spring, Maryland iTrader: (0)	http://blog.bavauto.com/14344/ I used this video to install camber plates, very detailed. __________________ 2010 128i manual, sport package, performance exhaust, Vorshlag camber plates, Bilstein B6 struts/shocks, 245/40/17 ZIII square on et 40 with rolled rear fenders.
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11-25-2013, 09:23 PM	#5
jwzimm Colonel 692 Rep 2,770 Posts Drives: '16 M3 Join Date: Jun 2011 Location: Renton, WA iTrader: (17)	Thanks for the link. I think the ECS Tuning video is more applicable though as I will be doing a full coilover setup. The main point I am making in this thread is that the bushings need to be re-indexed when you install lowering springs or a coilover system.
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11-25-2013, 11:22 PM	#6
edirtaynine Major General 84 Rep 6,088 Posts Drives: e92 Join Date: Mar 2011 Location: SoCal iTrader: (0)	i always do that to my suspension installs after my friend taught me it __________________ e90post killed plastidip Just say no to painted stock wheels jm3as hooks it up
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