Rear Spherical Bearings Conversion on Stock Arms

[Redd]

This info was collected from various sites and I am just posting it here for reference. Most of the engineering was done by vtl and fe1rx on 1addicts. You can read their full threads at the links below (very informative reads!):
vtl - https://www.1addicts.com/forums/show....php?t=1302309
fe1rx - https://www.1addicts.com/forums/show....php?t=1615006

The stock M3 suspension retains rubber bushes in various locations. These can be replaced with the parts listed in the table below to get a rear suspension with spherical bearings while using stock arms. This would be a good medium between stock suspension vs full race arms (SPL, Turner, etc) while still being relatively maintenance- and noise-free with sealed OEM-style bearings.



Parts Required
A. 1x BimmerWorld Rear Camber Arm Bearing Kit:
https://www.bimmerworld.com/BimmerWo...aring-Kit.html

B. 8x Lemforder 3067901 or Meyle 3147100005 bearings

C. 4x custom tapered washers

(Pic by vtl)

Item C (tapered washers) go in these locations (marked in red):


Item B, needs to be installed offset 3mm to allow space for Item C.

(Pic by vtl)

More details on installation of the guide rod and wishbone bearings with tapered washers here:
https://www.1addicts.com/forums/show...&postcount=293

Tapered washer designed by vtl:


Disclaimer - I'm posting this info for reference. I am still collecting all the parts required to do this conversion so I can't comment on complexity of the job. Will post details/reviews here as I do this mod later.

Edit 16Nov2023 - Custom tapered washers are available for sale from spikenipple . Email him at: ow_dont_pull_that@hotmail.com

[Redd]

I have 8 sets of tapered washers available for sale here at USD30 per set of 4 washers.

https://www.m3post.com/forums/showthread.php?p=26987547

[M43S7RO]

I'm pretty sure the guide rod and wishbone on the M3 uses spherical ball joints at inner and outer locations from factory, no need to replace these unless worn. If they are worn, prob easiest to just replace with oem arms which will have the spherical bushings pre-installed.

[Redd]

Originally Posted by M43S7RO

I'm pretty sure the guide rod and wishbone on the M3 uses spherical ball joints at inner and outer locations from factory, no need to replace these unless worn. If they are worn, prob easiest to just replace with oem arms which will have the spherical bushings pre-installed.

Nope they are not. I have a set of new guide rods and wishbones and they are rubber on the hub-side. Also you cannot press out the bearing on the subframe side as it is swaged into the arm itself. If that bearing is worn out you must replace the arm. That said, I have 130k kms on my car and still on original rear arms. The rubber is showing some cracks but the bearings are fine.

[derbo]

Originally Posted by M43S7RO

I'm pretty sure the guide rod and wishbone on the M3 uses spherical ball joints at inner and outer locations from factory, no need to replace these unless worn. If they are worn, prob easiest to just replace with oem arms which will have the spherical bushings pre-installed.

Can confirm that is not true. The table on the top of this thread is correct.

[tlrid3r]

Where to purchase the bearings tho.

[Redd]

Originally Posted by tlrid3r

Where to purchase the bearings tho.

Lemforders USD35/pc on eBay. Meyle USD18/pc on Fcpeuro.

[GORDON.M3]

Looks good, any idea if when replacing the bushings to bearings should I buy a new part to do it or modify the original ones on my car?

[Redd]

Originally Posted by GORDON.M3

Looks good, any idea if when replacing the bushings to bearings should I buy a new part to do it or modify the original ones on my car?

My arms were 130k kms old, so I got new OEM TRW arms and will be installing the bearings into those. If your car is low mileage I suppose you can re-use the original arms.

[M43S7RO]

My apologies! Wow, washers went quick.

Originally Posted by Redd

Nope they are not. I have a set of new guide rods and wishbones and they are rubber on the hub-side. Also you cannot press out the bearing on the subframe side as it is swaged into the arm itself. If that bearing is worn out you must replace the arm. That said, I have 130k kms on my car and still on original rear arms. The rubber is showing some cracks but the bearings are fine.

[Redd]

Originally Posted by M43S7RO

My apologies! Wow, washers went quick.

I've put your name on waitlist in case any buyer drops out.

[atopa2002]

wait list should in case some one drop out or you make more

[GORDON.M3]

Originally Posted by Redd

My arms were 130k kms old, so I got new OEM TRW arms and will be installing the bearings into those. If your car is low mileage I suppose you can re-use the original arms.

You're probably right, I'll end up buying a new set of TRW arms.

I find it funny how we are swapping non-m bushings in an M car now. When all the other non-M guys are trying to swap in M3 stuff.

[Redd]

Originally Posted by atopa2002

wait list should in case some one drop out or you make more

In case someone drops out. I would have to order another 10 sets for a production run, but I doubt it will be done in time for Jan delivery.

[atopa2002]

Originally Posted by Redd

In case someone drops out. I would have to order another 10 sets for a production run, but I doubt it will be done in time for Jan delivery.

Thanks ok , keep me in mind

To add to this I have done 1 and 2 in the table above using this bavauto tool
It made the job a walk in the park .

https://www.ecstuning.com/b-bav-auto-tools-parts/trailing-arm-bushing-tool-set/b8800101~bat/

[tdott]

Originally Posted by GORDON.M3

I find it funny how we are swapping non-m bushings in an M car now.

I think that is a bad analogy, it is replacing a bushing with a Spherical bearing.

[tsk94]

Very cool. Thanks for posting!

Great option for those who haven't upgraded to full spherical rear arms and want the performance benefits but at a more reasonable price and maintains that 'stock' appearance when looking under the car.

[derbo]

Originally Posted by GORDON.M3

You're probably right, I'll end up buying a new set of TRW arms.

I find it funny how we are swapping non-m bushings in an M car now. When all the other non-M guys are trying to swap in M3 stuff.

Lol the non-M guys also swap the M3 arms in and put this bearing in as stated in the 1 series posts up top. It appears they are the origin of the custom washers.

I like that we are replacing the rubber bushing with an OE Spherical bushing regardless if it is M or not.

[Redd]

Yeah those 1er guys are pretty hardcore. Fe1rx went so far as to reverse engineer the M3 arms, machine his own arms, then stress test them to failure. That's passion right there.

[///Mobbin]

Redd thanks for sharing all of this, very cool!

Just when I thought I was done with my suspension setup

[GORDON.M3]

Originally Posted by ///Mobbin

Redd thanks for sharing all of this, very cool!

Just when I thought I was done with my suspension setup

its never done.

[Redd]

Originally Posted by GORDON.M3

its never done.

Haha I know right? One year ago I told myself there's nothing left to do on the M3. Famous last words.