Front Wishbones (LCA's) needing replacement?

[DaanBMW]

Posted this on the N52 E92 forum with somewhat inconclusive replies, and since these are M3 front wishbones (lower control arms) I'll ask here hoping for a more clear answer:

See video below (from dealer). Is this "excessive" play normal or do the wishbones (front lower control arms) need replacement?

https://drive.google.com/file/d/1KjI...usp=share_link

[DaanBMW]

wow M3 forum and no opinions... anyone?

[DukeofAlexandria]

Originally Posted by DaanBMW

wow M3 forum and no opinions... anyone?

Well considering the M3 is a macpherson strut design and not a wishbone (single or double) I’d say noooooo….

But that doesn’t look like too much play and if you think it’s out, change them. You can inspect the bushings on the control arms and vertical stabilizer linkages pretty easily.

If you have excessive roll/sponginess or clicking/squeaking then it’s probably time for new control arms or ball joints.

-Duke

[DaanBMW]

BMW calls them wishbones, here is the link. https://www.realoem.com/bmw/enUS/sho...01#31102283577

Given the video was by a BMW tech during a recent recall, it got me confused, as I have no other symptoms (no squeaking or sloppiness in steering). I'll change anything on my car if needed or preventative, but here I'm a bit stumped...

[IamFODI]

Mine are like that. Though they are also 154k miles old....

I feel like those arms are bound to be able to twist around like that because of how they're mounted. It's just a ball joint at each end in roughly the same orientation. Nothing preventing that kind of twist.

That said, I'm sure there's a limit to how easy it should be. Hard to verify that in the video so you're basically taking the mechanic's word (or not).

What did you end up doing?

[DaanBMW]

I bought replacement M3 arms, and now I'm on the fence if I should go ahead and replace them or not. I have ~100k on them.

Was thinking I will get a deciding answer on the forums, but I'm still unclear if this is an issue or not, or at least how to decidingly test it.

[tdott]

The forces that arm is meant to hold, goes in towards the center of the car and out. That arm isn't meant to hold any twisting forces. So you are checking for play in the wrong direction.

[DaanBMW]

Originally Posted by tdott

The forces that arm is meant to hold, goes in towards the center of the car and out. That arm isn't meant to hold any twisting forces. So you are checking for play in the wrong direction.

I'm not doing any of the checking you see in the vid, it was at the dealer, including the audio saying they have "excessive" play.

Clueless bmw tech? possibly.

How does one confirm the arms are still working as designed? Axially (axis = the line unting the 2 ends of the arm)? if so, some play? no play? in this direction? also, do they need to perform at both ends of the twisting motion shown in the vid? if that twisting motion is a normal/required function, than likely the answer is yes.

these are me best guesses based on all this "no, this not the way to do it", I'm a mech engineer but not a suspension expert.

[tdott]

Originally Posted by DaanBMW

How does one confirm the arms are still working as designed? Axially (axis = the line unting the 2 ends of the arm)? if so, some play? no play? in this direction?

A pry bar on each joint to check for play, there should be none.

[CPWINCH]

I just replaced my thrust arms because I did the monoball conversion and chose to get them pre intalled into new arms. Make sure to buy the Lemforder arms instead of the TWS. TWS is taiwense made now and lemforder is german and has higher quality and more strength.

EDIT: just realized you are talking about the lower arms. If you are non M3 just replace them with fresh m3 arms.

As far as replacing the factory bearing it should last you about 120k miles. When I replaced mine it looked mighty crusty but the bearing itself was probably fine. I attatched photos of the old arm vs the new arm.

[IMG][/IMG]

[IamFODI]

Originally Posted by CPWINCH

Make sure to buy the Lemforder arms instead of the TWS. TWS is taiwense made now and lemforder is german and has higher quality and more strength.

TRW you mean?

I've also heard the new TRWs are different but I hadn't heard about quality or strength. Got any links on that?

Also, any idea of weight differences between Lemförder, new TRW, and original?

[CPWINCH]

Originally Posted by IamFODI

TRW you mean?

I've also heard the new TRWs are different but I hadn't heard about quality or strength. Got any links on that?

Also, any idea of weight differences between Lemförder, new TRW, and original?

Yes TRW, weight is negligible

[Ajolives]

The tech is trying to swindle you. ‘Worn’ doesn’t necessarily mean bad, and even new lowers do the same shit (albeit with a bit more effort).

In the past two months I’ve fielded almost a dozen dealership quotes from my peers at work - they’re all out to get that money. My buddy has a pedestrian Toyota with 15k miles and they tried to sell him $1k in preventative maintenance with fuel additives, injector cleaners, brake flush, etc; the car is not even two years old. Another has a 2013 Jeep Cherokee worth maybe 10k; 5k quote to fix an oil seep/leak.

Watching that video gave me the same vibes of let’s throw some shit at the wall and see if it’ll stick.

That being said, the new arms would probably give you a bit more steering feel simply because they’ll likely perform better than the aged parts on the car.

[DaanBMW]

Originally Posted by Ajolives

The tech is trying to swindle you. ‘Worn’ doesn’t necessarily mean bad, and even new lowers do the same shit (albeit with a bit more effort).

In the past two months I’ve fielded almost a dozen dealership quotes from my peers at work - they’re all out to get that money. My buddy has a pedestrian Toyota with 15k miles and they tried to sell him $1k in preventative maintenance with fuel additives, injector cleaners, brake flush, etc; the car is not even two years old. Another has a 2013 Jeep Cherokee worth maybe 10k; 5k quote to fix an oil seep/leak.

Watching that video gave me the same vibes of let’s throw some shit at the wall and see if it’ll stick.

That being said, the new arms would probably give you a bit more steering feel simply because they’ll likely perform better than the aged parts on the car.

agreed, I don't really go for anything the dealer dishes out (esp. the most frequent: the "tires are near limit" and associated $1,400+ quote). the odd thing about it all is that while the vid hinted at the need for arms replacement, and then a bit later (not in the snip I posted) that they'll give me a quote to replace arms, it never materialized...

I think I'll just wait a bit more and then maybe swap them since I already got new ones in hand. Nothing in the steering feels sloppy ...but then a "boiling the frog" concept of slow and unnoticed changes can be at work too.

And while this whole Lemforder vs TRW now surfaced - for the upper arms not these lower ones - the fact that FCP sells the TRW is for me guarantee enough.

[IamFODI]

Originally Posted by CPWINCH

Yes TRW, weight is negligible

Thanks for posting. That's interesting. Didn't see anything on weight but you're probably right that the difference is negligible between Lemförder and old TRW.

I'd be interested to see the same comparison between old TRW and new TRW.

[studiogroverbeach]

I just replaced my 'lower control arms' (wishbones). The video you posted is a bit hard to see how much play there actually is, because it is low-res, but it looks like the amount of play is excessive, not in terms of the distance of play, but the ease of play (stiffness).

Mine were original parts, 80K miles on the car. After replacement, the steering is much more precise, and no noticeable delay in wheel turning. The turn-in is very sharp and pointed.

I posted more info here: https://www.m3post.com/forums/showthread.php?t=2023530

If you think your steering feels loose or sloppy, definitely replace the LCAs. It's a ~2 hour job if you have the right tools and nothing is stuck. In my case, I had to make multiple trips to the hardware store (broke two T40 Torx bits), and the passenger side LCA was frozen in the knuckle. See my solution = 3 lb sledge hammer!