Rear Spherical Bearings Conversion on Stock Arms

[Redd]

Originally Posted by amg6975

I like this solution a lot. I didn't realize it was an option but I think I'll be going with this.

I would also say, I would not hesitate to run spherical on the toe link, the one on the very back side of the knuckle. I think that will see the most benefit from the spherical, has not had any issues, and doesn't even have the factory taper.

Problem with PU has always been noise. They will dry up and squeak after a few months.

Our M3 stock toe links are already spherical on both ends. The weakness of the stock toe link is the eccentric bolt that is used to set the toe.

[Ghmpin]

Rogue has some similar to what SPL has. It’s a spherical insert, not a washer.

https://www.rogueengineering.com/Rog...-V20_p_92.html

[ENinetyLou]

Originally Posted by kolosy

So I got my missing groundcontrol washers, and ended up with a set of ones meant for the spherical conversion (bought them before changing my mind). it's an interesting comparison

Attachment 3369898

Attachment 3369899

Attachment 3369900

the GC ones are 1.5mm thicker, and have an odd lip on the flat side. i was going to say that it mates up with the spherical bushing inside the arm, but it doesn't -- the opening is smaller than the OD of the bushing. hopefully they aren't just wrong, but not sure what the purpose of that cut out is.

I just got a set of Ground Control Rear Arms and they came with 8 washers like this. After reading about the bolt shearing situations, I'm strongly considering returning these GC Arms and just postponing my control arm replacements.

Going to call GC tomorrow and ask them about this issue and if they've heard about it. Anybody already spoken with them?

[tsk94]

Originally Posted by MaximusB

Has anyone with GC arms managed to shear a bolt?

Originally Posted by Redd

Not to my knowledge but I don't keep track of those things.

I had no issues with mine for ~3 seasons on my previous car. Not saying that means they cannot fail though.
I just bought another set for my new build, so hopefully all is good this time around again...

[ENinetyLou]

Originally Posted by tsk94

I had no issues with mine for ~3 seasons on my previous car. Not saying that means they cannot fail though.
I just bought another set for my new build, so hopefully all is good this time around again...

What kind of bolts did you install with? Factory bolts or ARP? How many track days through those ~3 seasons?

[tsk94]

Originally Posted by ENinetyLou

What kind of bolts did you install with? Factory bolts or ARP? How many track days through those ~3 seasons?

I did new OEM bolts.
~45-50 days on them in that time.

[amg6975]

I got around to doing the Powerflex Black bushing install. I'm a lot happier with this solution. I can't imagine the difference between this and bearings will be noticeable, and these were way easier to install. I used new ARP bolts for this install, torqued to 98ft-lbs.

Again not really a professional opinion but I'll certainly sleep better at night.

[testdriver]

Originally Posted by MineralWhiteF80

after reading this thread three separate times, my current opinion is that leaving my two OEM upper arms alone and dealing with a little more deflection is better than any gains I might see by changing the two rubber outer bushings to bearings with the possibility of suspension failures that lead to crashing Especially if I do the trailing arm and lower spring/camber arms with all bearings.

I'll change the lower spring arm and trailing arm rubber bushings out, but only way I'd mess with the two upper arms is by going with SPL Parts arms (or equivalent). It's just not worth it for my simply HPDE track car.

I have the same feeling as well.

At first I was excited to see this low cost options which can make improvement on our car. But it looks like if you do any track driving/ HPDE, the added washer for putting up the bearing can be a point of risk uncertainly to the whole thing.

In the rear suspension, I already hv the solid bushing subframe. I was planning to change out some bushing to bearing, now after reading all this, I decide if I have to swap bushing to bearing, I only pick those which I do not need to add any spacer/ washer or alter to length of the whole pieces to replace.

I guess one of the example would be the Rear lower control (spring) arm Inner bushing. This can be upgrade to bearing with little worries.


At the end I would like to say THANK YOU to many who willing to share their "successful" and "unfortunate" experience on this topic.

[Redd]

Just finished a trackday Sat night. Drove 55 mins straight at Sepang International Circuit. Zero issues with the sphericals. That said I was only on AD08R tires and no aero, so not extreme amounts of grip. I did ride the kerbs pretty hard tho.

At this stage I'm comfortable with the strength/safety of the spherical conversion for anything up to trackdays. If you're a competitive driver or doing time attack or racing then probably race arms are better.

[bipp]

I've been reading about this approach of removing the rubber while retaining stock arms, but I've found some other "package" approaches to this that take the self-sourcing out of it.

As an example, there's the Laptorr kit (https://laptorr.com/collections/m/E92-M3) and the Schirmer kit (https://www.teamschirmerparts.com/pr...s-gt-rear-axle) that provide full sphericals and eccentric camber arm bearing. Would this be a similar but safer approach? It definitely appears that going spherical isn't the problem but rather the improper use of washers, so maybe a "kit" is likely to mitigate some of that risk? (edit: ignoring the somewhat absurd pricing from both of those vendors, I see that SPL has the bearings for far cheaper)

[Redd]

IND now offers this spherical kit for the rear wishbone and guide rod (the two rear upper arms). Looks like the conical face is built in, so no need to use the custom tapered washer. Might be a stronger solution for the trackies.

https://www.m3post.com/forums/showthread.php?t=2135761

[bipp]

Originally Posted by Redd

IND now offers this spherical kit for the rear wishbone and guide rod (the two rear upper arms). Looks like the conical face is built in, so no need to use the custom tapered washer. Might be a stronger solution for the trackies.

https://www.m3post.com/forums/showthread.php?t=2135761

This looks like this (https://laptorr.com/collections/m/pr...83%BC%E3%83%A0) albeit with the extra ring and costing $400 less. It has the extra piece and is SS throughout whereas Laptorr uses a bearing from Minebea (unknown material?) and a SS housing.

Laptorr also has the trailing arm bearing. I think those are the last two I need to replace to de-rubber the rear end of my car (albeit still sticking with OEM diff mounts).

[Redd]

Japanese tuner parts are crazy expensive. Even Schirmer uses the $15 Meyle bearings for trailing arm position. So I think that's more than good enough.

[darren p.]

Originally Posted by Redd

Japanese tuner parts are crazy expensive. Even Schirmer uses the $15 Meyle bearings for trailing arm position. So I think that's more than good enough.

Getting ready to source everything.

FCP has these Meyle bearings that you listed on the 1st page for the trailing arms but its not showing compatible? https://www.fcpeuro.com/products/bmw...ing-3147100005

Are these the correct ones for the trailing arm?

Going to get the RevShift Trailing arm as well...or the Fall Line if someone wants to comment on which is better? Fall line are almost twice the cost.
https://ind-distribution.com/product...ailing-arm-set vs https://revshift.com/products/rear-t...8aAk8CEALw_wcB



Going to go with the GC Guide Arms, Wishbone Arms and the Toe Arms too
https://groundcontrolstore.com/colle...nt=35876177539

[Redd]

Originally Posted by darren p.

Getting ready to source everything.

FCP has these Meyle bearings that you listed on the 1st page for the trailing arms but its not showing compatible? https://www.fcpeuro.com/products/bmw...ing-3147100005

Are these the correct ones for the trailing arm?

These bearings are not official replacement parts for E9x M3 so they won't show as compatible. But they work.

I'm using ECS trailing arms. I think any will work. Based on how weak the stock trailing arms are I don't think there's a need to over-engineer the part.

[Scharbag]

Just completed this job. Wow - what a bit of a job. Also threw some Ohlins in at the same time - along with Ground Control camber plates, solid subframe bushings and purple diff bushings.

Wanted to say thank you to all the posters on this thread - a great help and such a neat re-use of other parts and little bits and bobs. Need to get an alignment and then give it a good shakedown.

I think I got the ride height OK. Took 4 tries... Bleh. But we got it done.

I do regret not buying the proper pulling kit as boy oh boy, the amazon special was not helpful in some situations. But 32mm chrome sockets worked well... Don't judge me

Cheers,

[houtan]

Originally Posted by Scharbag

Just completed this job. Wow - what a bit of a job. Also threw some Ohlins in at the same time - along with Ground Control camber plates, solid subframe bushings and purple diff bushings.

Wanted to say thank you to all the posters on this thread - a great help and such a neat re-use of other parts and little bits and bobs. Need to get an alignment and then give it a good shakedown.

I think I got the ride height OK. Took 4 tries... Bleh. But we got it done.

I do regret not buying the proper pulling kit as boy oh boy, the amazon special was not helpful in some situations. But 32mm chrome sockets worked well... Don't judge me

Cheers,

Nice job. There are multiple options discussed in this thread. Which one did you go with?

[Redd]

Nice! Give the Ohlins 500 miles to settle then give it a final ride height adjustment.

[Scharbag]

Originally Posted by houtan

Nice job. There are multiple options discussed in this thread. Which one did you go with?

So I bought the spherical bearings from FCP and the sleeve thingers and conical washers from M Arter. Given this will not see the track, I am not too worried about breaking bolts.

For the subframe bushings, I went with RevShift 2 piece aluminum as I did not want to have to deal with installing solid aluminum ones as it looks like a total PITA. Just getting the stock ones out sucked major bag.

Diff bushings I went with PowerFlex Purple. Regretting that a little bit as I seem to have some increased NVH at highway speeds. But I knew there was a risk. Debated just replacing the factory one - may still do that if the noice bothers me too much.

While I was in there, replied the transmission mounts - waste of time and money there. At 99TKM, the original ones could likely be resold as new. But, such is life. Also did my flex disk - looked in pretty good shape but might as well when in there.

So far, feels good. The Ohlins are tight, may back them off a little as they are set right in the middle of their adjustment range. Feel is excellent and more settled in the twisty bits. Happy I did all that work - and it is a lot of work.

Cheers,

[D989]

Originally Posted by darren p.

Getting ready to source everything.

FCP has these Meyle bearings that you listed on the 1st page for the trailing arms but its not showing compatible? https://www.fcpeuro.com/products/bmw...ing-3147100005

Are these the correct ones for the trailing arm?

Going to get the RevShift Trailing arm as well...or the Fall Line if someone wants to comment on which is better? Fall line are almost twice the cost.
https://ind-distribution.com/product...ailing-arm-set vs https://revshift.com/products/rear-t...8aAk8CEALw_wcB



Going to go with the GC Guide Arms, Wishbone Arms and the Toe Arms too
https://groundcontrolstore.com/colle...nt=35876177539

What are your thoughts on the GC rear arm set? I need to replace the stock upper arms and don't want added NVH. I also need a good toe arm. I am having trouble sourcing German made m3 arms so I now I am considering the American aftermarket brands.

[Redd]

Can recommend the Dinan rear toe arms. I bought mine used from a track driven M3, and have had them for 8 yrs, 65k kms now so they must be at least 10 years old by now. Zero issues, zero NVH.

[ThatKidDavid]

Sub’d