You were by far the most knowledgeable person on UA-cam that wasn't able to explain anything and properly obtain this information I thank you buddy I have an XI 2010 and it takes a sway bar but I'm going somewhat aftermarket OEM have a good day thank you again
Back almost a year later :) Did the install of the upper two by your guide, as excellent and good time saving. I went for reinforced rubber rather then pillowball for better street usage. I am really happy with the result from the traction strut, quite noticeable reslusts, specially for normal driving. I talked with a friend that works with designing cars and struts (and control arms) at one the larger car brands, he told me that the lower two of BMWs rear control arms have stress concentration and are designed to break of in a collision, as to prevent the gas tank from becoming punctured, that why E90 has a weird looking rear control arms if you seen it, additionally the toe arm is suppose to be able to flex during cornering. So pillowball and solid steel arms are really only for the track and not street use, for the this reason hardrace only make the upper two in reinforced rubber, all for exists in pillowball, this could explain why you wheren't happy with your results. Thanks again for the video.
From the final alignment settings you presented - (1) why did you decide on that specific rear Total Toe setting (i.e. almost identical to that of the front, rather than more toe-in than front) and (2) you have a lot of negative camber on the front (more than rear) is there any specific reason its approx 1.5 x more than the rear camber? Many thanks in advance for your advice/feedback.
Since this is an awd vehicle it doesn't need nearly as much rear toe as a rwd BMW for stability. For the camber, BMWs typically need a degree or more of negative front camber over the rear for better grip in turns. Part of this is due to the Macpherson strut design which tends to lose negative camber as the suspension compresses, so you start with more static camber than you might actually need. The rear suspension multi-link design is the opposite and actually gains negative camber as it compresses.
Hello. I have a F30 from 2020 320i car. I just smashed it at over 70 mph on the side on a roundabout because i was stupid. Now i have to change my front wheel arms and rear wheel arms...Now my car is at an mechanic workshop, which i know he is a fairly good guy i think (in Romania many mechanics guys wanna reap you off). He told me I have to change 3 arms in front, all 5 from the rear and after that to bring it for alignment test. Man I really love my car, what do you think... Is it possible that in the future it will drive differently if he changes al the arms correctly? Or It can be as new, and never have problem again? Sorry for my bad English and long comment. I really enjoyed the quality of the video.
If you're not familiar with the job and figuring out the angles to work around things I'd budget 2-3hrs for the first side, and then half that amount for the 2nd side since you'll be more familiar with it.
All the arms are listed on Megan Racing's site: meganracing.com/suspension/type-suspension-arms/euro?find=bmw-3-series-2017-10617&sid=T6EVuV8rgd The traction strut is the "rear upper front camber arm" MRS-BM-0320
Great video! I have an f30 m sport, currently suffering severe toe angle changes on even the smallest road imperfections. Do I have to replace all five arms? My gut says that it's only the arms with the balljoints that attach to the wheel carrier, so the rollover strut and lower wishbone? Also if that is indeed the case can I not just replace the balljoints on those? Thanks and cheers.
Wow, how were you able to see the toe changing while driving? GoPro mounted in the wheel well? I'd take a look at just the rearmost toe arm first. By chance is the eccentric bolt moving? Could it be possible it's not clamped properly? It's probably cheaper to just get new arms than to try and replace individual ball joints in these arms. Even if the ball joints themselves are cheaper, the labor will likely cost you more.
Lol no I can't see it, but I can feel the rear 'steering itself' on bad/uneven surfaces. Rear just doesn't feel located. On my e46 worn Rear Trailing Arm Bushes caused that. Thanks for the tip, guess I'll just change the arms. Got the car with high mileage (200k KMs), suspension was pretty much toast. So far have fit Koni Yellows, HR Super Sports, HR Trak Plus spacers and new Michelin PS4S all round. Then I found that the driver's side rear sticks out about a half inch more than passenger side and was rubbing. So had to remove the spacers at the rear, no more rubbing. Will tackle the arms now. Apologies for the long reply, not much detailed rear suspension videos for F series. Appreciated!
Some idiot crashed into my car (F36) while it was parked and destroyed my rim (rear driver side). So naturally I was concerned how much damage was done. After I took the destroyed wheel off it appears that only the traction strut is bent. I checked all other control arms and they all look fine. So instead of paying the $1k deductible for my insurance to fix it I can do it myself. The part is about $100. My question is, how do I know what “normal resting position” is? Do I just jack up the wheel carrier until it stops?
If you measure the distance from the wheel hub to the fender with the car on the ground, that's the normal resting height. You'd jack up the wheel carrier to create that same distance with the car in the air. That said, you don't have to get it EXACT, and "close enough is good enough."
@@FaRKle0079 I am running the hardrace front trailing arm and wishbone on my F30, also with Bilstein dampers ;) Looking to doing the rear as well in the future. Could you tell me a bit about the handling difference from changing the rear control arms? I did my front arms independently and had good fun seeing exactly what each of them effected.
@@nullpointer1984 To be honest, the rear arms don't do very much. I do notice the rear feeling like it articulates a bit better in very hard driving, like at the track, and maybe a bit better hard braking stability, but there's almost no benefit on the street. Changing front arms has a much greater effect than rear ones.
I'll have a video on just the arms themselves, but the short answer is, no significant handling benefit unless cornering really hard. I think you'd need to be on an AutoX course or HPDE to start to see benefits (which would still be subtle). One nice thing though, is no significant increase in NVH either.
@@FaRKle0079 Hi what are your thoughts on longevity? My stock toe arm bushings are shot after 114k kms. This has resulted in crazy tire wear. I am debating getting these Megan ones over new stock. Also if I do is it worth doing them all as you did? The also for the great vid.
@@trashpandaracing3131 I don't have any concerns about the longevity of these parts. The monoball is fully sealed so you don't need to worry about contamination getting in there. I don't think it's really worth doing all the arms on a street car, there might be a bit of benefit for a track car, but I think it's kind of subtle.
A "floaty" feeling is due to being under damped where the body motions aren't well controlled. Going to different dampers with higher damping will help.
That arm is pretty simple conceptually with the bolt at the wheel carrier side and the other eccentric bolt on the subframe side. For the wheel carrier, damper, and spring parts you can check out my springs and shocks swap video. ua-cam.com/video/p6usLM8-FIQ/v-deo.html For the eccentric camber bolt on the subframe side the torque spec is 165 Nm / 122 ft lbs and should be tightened at normal position. Don't forget to disconnect the ride height level sensor.
You were by far the most knowledgeable person on UA-cam that wasn't able to explain anything and properly obtain this information I thank you buddy I have an XI 2010 and it takes a sway bar but I'm going somewhat aftermarket OEM have a good day thank you again
Back almost a year later :) Did the install of the upper two by your guide, as excellent and good time saving. I went for reinforced rubber rather then pillowball for better street usage. I am really happy with the result from the traction strut, quite noticeable reslusts, specially for normal driving. I talked with a friend that works with designing cars and struts (and control arms) at one the larger car brands, he told me that the lower two of BMWs rear control arms have stress concentration and are designed to break of in a collision, as to prevent the gas tank from becoming punctured, that why E90 has a weird looking rear control arms if you seen it, additionally the toe arm is suppose to be able to flex during cornering. So pillowball and solid steel arms are really only for the track and not street use, for the this reason hardrace only make the upper two in reinforced rubber, all for exists in pillowball, this could explain why you wheren't happy with your results. Thanks again for the video.
Another excellent video. Your voice is so calm and you explain everything in a very clear way. Thanks!
Thanks!
Very very good video happy i found you
Excellent video!
Great vid!
Thanks a lot for the great video!!!
You’re g for that
From the final alignment settings you presented - (1) why did you decide on that specific rear Total Toe setting (i.e. almost identical to that of the front, rather than more toe-in than front) and (2) you have a lot of negative camber on the front (more than rear) is there any specific reason its approx 1.5 x more than the rear camber? Many thanks in advance for your advice/feedback.
Since this is an awd vehicle it doesn't need nearly as much rear toe as a rwd BMW for stability. For the camber, BMWs typically need a degree or more of negative front camber over the rear for better grip in turns. Part of this is due to the Macpherson strut design which tends to lose negative camber as the suspension compresses, so you start with more static camber than you might actually need. The rear suspension multi-link design is the opposite and actually gains negative camber as it compresses.
@@FaRKle0079 thank you. much appreciated.
Hello. I have a F30 from 2020 320i car. I just smashed it at over 70 mph on the side on a roundabout because i was stupid. Now i have to change my front wheel arms and rear wheel arms...Now my car is at an mechanic workshop, which i know he is a fairly good guy i think (in Romania many mechanics guys wanna reap you off). He told me I have to change 3 arms in front, all 5 from the rear and after that to bring it for alignment test. Man I really love my car, what do you think... Is it possible that in the future it will drive differently if he changes al the arms correctly? Or It can be as new, and never have problem again? Sorry for my bad English and long comment. I really enjoyed the quality of the video.
Excellent Vid! just what i needed. just out of curiosity how long did the actual job take?
If you're not familiar with the job and figuring out the angles to work around things I'd budget 2-3hrs for the first side, and then half that amount for the 2nd side since you'll be more familiar with it.
How come I can’t find Megan racing traction arms? No link here either…
All the arms are listed on Megan Racing's site:
meganracing.com/suspension/type-suspension-arms/euro?find=bmw-3-series-2017-10617&sid=T6EVuV8rgd
The traction strut is the "rear upper front camber arm" MRS-BM-0320
How are the Megan arms doing for ya? I'm at 143K miles with the originals and need to replace here soon (a bit squishy in the rear).
They're doing well, no complaints. That said the benefit is pretty marginal, and I don't think they're worth the extra $ for a street car.
Great video!
I have an f30 m sport, currently suffering severe toe angle changes on even the smallest road imperfections. Do I have to replace all five arms? My gut says that it's only the arms with the balljoints that attach to the wheel carrier, so the rollover strut and lower wishbone? Also if that is indeed the case can I not just replace the balljoints on those?
Thanks and cheers.
Wow, how were you able to see the toe changing while driving? GoPro mounted in the wheel well?
I'd take a look at just the rearmost toe arm first. By chance is the eccentric bolt moving? Could it be possible it's not clamped properly?
It's probably cheaper to just get new arms than to try and replace individual ball joints in these arms. Even if the ball joints themselves are cheaper, the labor will likely cost you more.
Lol no I can't see it, but I can feel the rear 'steering itself' on bad/uneven surfaces. Rear just doesn't feel located. On my e46 worn Rear Trailing Arm Bushes caused that. Thanks for the tip, guess I'll just change the arms.
Got the car with high mileage (200k KMs), suspension was pretty much toast. So far have fit Koni Yellows, HR Super Sports, HR Trak Plus spacers and new Michelin PS4S all round. Then I found that the driver's side rear sticks out about a half inch more than passenger side and was rubbing. So had to remove the spacers at the rear, no more rubbing. Will tackle the arms now.
Apologies for the long reply, not much detailed rear suspension videos for F series. Appreciated!
How did the car feel after?
Some idiot crashed into my car (F36) while it was parked and destroyed my rim (rear driver side). So naturally I was concerned how much damage was done. After I took the destroyed wheel off it appears that only the traction strut is bent. I checked all other control arms and they all look fine. So instead of paying the $1k deductible for my insurance to fix it I can do it myself. The part is about $100. My question is, how do I know what “normal resting position” is? Do I just jack up the wheel carrier until it stops?
If you measure the distance from the wheel hub to the fender with the car on the ground, that's the normal resting height. You'd jack up the wheel carrier to create that same distance with the car in the air. That said, you don't have to get it EXACT, and "close enough is good enough."
@@FaRKle0079 awesome thanks for the response I appreciate you.
May i ask what rear control arms help with?
Is Megan racing same as Hard race? Sure looks the same.
I believe Megan rebrands the Hard race part for the US market. There are some other parts they do this for too (like the sway bars).
@@FaRKle0079 I am running the hardrace front trailing arm and wishbone on my F30, also with Bilstein dampers ;) Looking to doing the rear as well in the future. Could you tell me a bit about the handling difference from changing the rear control arms? I did my front arms independently and had good fun seeing exactly what each of them effected.
@@nullpointer1984 To be honest, the rear arms don't do very much. I do notice the rear feeling like it articulates a bit better in very hard driving, like at the track, and maybe a bit better hard braking stability, but there's almost no benefit on the street. Changing front arms has a much greater effect than rear ones.
@@FaRKle0079 wow, that was good information. The four arms do cost quite a lot
What's your take on these so far? Any tangible improvement beyond better adjustability?
I'll have a video on just the arms themselves, but the short answer is, no significant handling benefit unless cornering really hard. I think you'd need to be on an AutoX course or HPDE to start to see benefits (which would still be subtle). One nice thing though, is no significant increase in NVH either.
@@FaRKle0079 Hi what are your thoughts on longevity? My stock toe arm bushings are shot after 114k kms. This has resulted in crazy tire wear. I am debating getting these Megan ones over new stock. Also if I do is it worth doing them all as you did? The also for the great vid.
@@trashpandaracing3131 I don't have any concerns about the longevity of these parts. The monoball is fully sealed so you don't need to worry about contamination getting in there.
I don't think it's really worth doing all the arms on a street car, there might be a bit of benefit for a track car, but I think it's kind of subtle.
@@FaRKle0079 Thanks for the insight. I will just do the toe bar and hope it last longer than the stock one did.
Besides coilovers, what can be done to the rear end to solve the floaty feeling at highway speeds?
A "floaty" feeling is due to being under damped where the body motions aren't well controlled. Going to different dampers with higher damping will help.
I need help with the camber arm
That arm is pretty simple conceptually with the bolt at the wheel carrier side and the other eccentric bolt on the subframe side. For the wheel carrier, damper, and spring parts you can check out my springs and shocks swap video. ua-cam.com/video/p6usLM8-FIQ/v-deo.html
For the eccentric camber bolt on the subframe side the torque spec is 165 Nm / 122 ft lbs and should be tightened at normal position. Don't forget to disconnect the ride height level sensor.
why we need to replace it with the new rod?
You don't "need" to replace these arms, but some people like to for more alignment adjustability, or to reduce deflection movement from the bushings.
@@FaRKle0079 thanks, I see.