Re-indexing after spring install

MikeD9 · 03-30-2021, 09:49 PM

I don't see many posts about this, but just wanted to see what people do when putting on new nuts and bolts to re-index the bushings. I'm having a hell of a time figuring out how some of the bolts can be pulled out with the subframe still on the car (specifically the rear ones). Also what's the trick to tighten the bolts when the suspension is under load, there is a lack of space to get a torque wrench in there when trying to do it from the bottom, my next attempt will be to drop the car down with blocks under the lower control arm to compress it with the wheel off and tighten it that way hopefully. Additionally, are people only doing bushings that are vertical, or horizontal ones too?

Lastly, I ran into a situation where the control arm that attaches to the hub came out and I noticed little dimples sticking out of it and small indents on the hub that they fit in, I tried to align them but in a scenario where they are not pressed together, is there risk of failure?

Thanks!

FaRKle! · 03-30-2021, 11:41 PM

Yes, it's an absolute pain to work on the rear control arms, but it is doable without lowering the subframe. I replaced almost all the arms on my F31. You do need to torque them at ride height, and you can use a jack to lift the wheel carrier up to the normal position.

You may have to get creative with torquing them such as using crows feet wrenches or offset torque tool. I was able to do all of my F31's with crows feet.

As for the little dimples on the ball joint face, don't worry about indexing those, it's not needed.

You can see my F31 rear arms swap in the below video:

Quote:

Originally Posted by Index

0:00 Intro
0:29 Wheels and covers removal
0:46 Rear suspension arms overview
3:13 Trailing arm removal and installation
7:33 Positioning the wheel carrier assembly in the "normal" position
9:37 Traction strut removal and installation
13:21 Wishbone arm removal and installation
18:40 Toe arm removal and installation
22:18 Covers, lines, and wheels installation
22:51 Alignment change after arms swap

MikeD9 · 03-31-2021, 12:20 AM

@FaRKle! Thank you!

ROBM2C · 03-31-2021, 10:06 AM

I have heard by very very reputable mechanics that none of this needs to be done . So many people just swap coilovers in and have zero issues .

M Fifty · 03-31-2021, 02:32 PM

BMW don't suggest it with the MPS - but then the lowering isn't huge.

Although the instructions say torque them up at ride height (which can be achieved in a number of ways), if you do them up enough to seat them at ride height - so they won't move if you jack the car up - you can then torque them fully with the wheels in the air.

03-30-2021, 09:49 PM	#1
MikeD9 Private 43 Rep 47 Posts Drives: M2 Competition Join Date: Apr 2020 Location: New Jersey iTrader: (1)	Re-indexing after spring install I don't see many posts about this, but just wanted to see what people do when putting on new nuts and bolts to re-index the bushings. I'm having a hell of a time figuring out how some of the bolts can be pulled out with the subframe still on the car (specifically the rear ones). Also what's the trick to tighten the bolts when the suspension is under load, there is a lack of space to get a torque wrench in there when trying to do it from the bottom, my next attempt will be to drop the car down with blocks under the lower control arm to compress it with the wheel off and tighten it that way hopefully. Additionally, are people only doing bushings that are vertical, or horizontal ones too? Lastly, I ran into a situation where the control arm that attaches to the hub came out and I noticed little dimples sticking out of it and small indents on the hub that they fit in, I tried to align them but in a scenario where they are not pressed together, is there risk of failure? Thanks! Attached Images
	Appreciate 0 Tweet Quote

03-31-2021, 12:20 AM	#3
MikeD9 Private 43 Rep 47 Posts Drives: M2 Competition Join Date: Apr 2020 Location: New Jersey iTrader: (1)	@FaRKle! Thank you!
	Appreciate 0 Quote

03-31-2021, 10:06 AM	#4
ROBM2C Lieutenant 314 Rep 438 Posts Drives: BMW M2C , DATSUN 260z, Porche Join Date: Dec 2019 Location: Ottawa Canada iTrader: (0)	I have heard by very very reputable mechanics that none of this needs to be done . So many people just swap coilovers in and have zero issues .
	Appreciate 0 Quote

03-31-2021, 02:32 PM	#5
M Fifty Banned 847 Rep 1,962 Posts Drives: M2 & 330CI Join Date: May 2018 Location: The Interweb iTrader: (0)	BMW don't suggest it with the MPS - but then the lowering isn't huge. Although the instructions say torque them up at ride height (which can be achieved in a number of ways), if you do them up enough to seat them at ride height - so they won't move if you jack the car up - you can then torque them fully with the wheels in the air.
	Appreciate 0 Quote