BMW E46 Fanatics Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
457 Posts
Discussion Starter #1 (Edited)
So I got new bushings and now the left front wheel is vibrating a bit, is it the ball joints? Replace the control arm? The steering coupler? Wheel balance? Alignment? Any thoughts?

Happens around 40-65 feel it around 30 too

Sent from BimmerApp mobile app
 

·
Premium Member
Joined
·
28,968 Posts
2 words - Bent Wheels!

This is the very first thing you have to rule out. Contrary to popular belief, wheel balancers do not make wheels round again. You can all all the weight you want onto a bent wheel and at the end of the day the balancer can show zero weight required and the wheel will STILL vibrate.

If you have questions, I can explain how to look for a bent wheel, otherwise rule out bent wheels first.
 

·
Registered
Joined
·
5,340 Posts
What kind of bushing did you install, has this started after you installed them?
 

·
Registered
Joined
·
457 Posts
Discussion Starter #5
2 words - Bent Wheels!

This is the very first thing you have to rule out. Contrary to popular belief, wheel balancers do not make wheels round again. You can all all the weight you want onto a bent wheel and at the end of the day the balancer can show zero weight required and the wheel will STILL vibrate.

If you have questions, I can explain how to look for a bent wheel, otherwise rule out bent wheels first.
What should I look for? And it goes away at higher speed.


The bushings were oem, only thing I could get quick enough. It did happen a little bit before them as well


Sent from BimmerApp mobile app
 

·
Banned
Joined
·
2,308 Posts
You only feel a warped rotor under braking. You just have a wheel out of balance. Only problem is, if you've been running unbalanced for a while, the tire will be shaped funny. That means if you get it re-balanced, it may still vibrate and there's not much you can do about it short of getting a new tire.
 

·
Premium Member
Joined
·
28,968 Posts
What should I look for? And it goes away at higher speed. The bushings were oem, only thing I could get quick enough. It did happen a little bit before them as well
Almost all imbalances are speed dependent, they have a resonant frequency and come and go depending on the speed. Your vibration likely will come back at a higher speed, maybe you have just not hit the higher resonant speed??

Anyway, most bent wheels can be identified by eye without the need to special or fine measurement equipment. Some minor bends are harder to find than the major bend. Since it appears the problem is in the front of the car, this makes it a bit easier to check and locate problems. Most bends are usually on the inside of the wheel as this side of the wheel is usually not as beefy as the outside of the rim.

Usually you can just jack up one side of the car at a time. Enough to get the tire off the ground. You spin the wheel and watch in one location the edge of the rim and see if you can visually see any variation in the edge of the rim. Try this from the outside of the wheel first, then do the same for the inside of the wheel. If you have a hard time, get something stationary to put up close to the wheel likely a scrap of wood, a spray can or anything you can use that will stay stationary. Then watch carefully.

The next test it to either put a piece of scape wood directly under the tire tread or just use the pavement as a reference. Then lower the tire tread withing about 1/8" of the wood or pavement and spin the tire while watching the distance between the tire and the scrap of wood or pavement. If you see any significant variation in this distance you likely have a bent wheel. Usually bent wheels will give low spots at the tread line. This will be VERY obvious. I have seen low spots of close to 1/2" an inch before!

The last thing to watch for is tread roll. While spinning the tire, look directly at the tread from the front of the car. Watch the tread pattern carefully and watch for any unusual side to side variation of the tread pattern or any rolling of the tread pattern either on the inside or outside edge of the tire tread. Sometime this may be just a subtle tread roll or variation, but you will likely see differences between a good and bad tire/wheel combination.

The bottom line is any unusual variation in the side to side movement of a wheel or tire and any unusual variation of up and down movement of the tire tread are indication of a problem, usually with the wheel, but it could also be a problem tire.

Tires are consumable, so the will get changed/replaced at some point, wheels are not usually consumable, but they get quite a beating with the low profile tires and the lighter the wheel, the easier is bends.

You could also rotate the tires front to back as a test. I would rotate only side at a time as this helps narrow down exactly what wheel/tire is a problem.

Also keep in mind the best tire balancing will not correct for a bad wheel or tire. The tire balancer can make the tire balanced, but it cannot correct for something that is out of round, just out of balance due to a weight distribution issue. I have personally seen even the Hunter Road Force Balancer display zero weight required on a tire/wheel that had a bend that caused a vibration. A VERY good tire tech using a very unconventional method on the Hunter Road Force balancer can identify a bent wheel, but unfortunately the Hunter Road Force machine by itself cannot flag a bent wheel. This has to be up to a VERY observant tire tech and most tire techs do not pay enough attention to wheel and rim problems.

I have dealt with 8-10 bent rims over the years and I am now VERY good at identifying and flagging bent rims. Sometimes I find them when I am not even looking for them and do not even realize I had a problem!

If it turns out you do not have a wheel/tire issue, then you need to start inspecting your brakes and suspension closer, but problem wheels and tires are a far bigger issue and they do get overlooked ALL the time. Do not rely on the tire techs to pinpoint and solve these problems, you have to find them yourself.
 

·
Registered
Joined
·
457 Posts
Discussion Starter #8
Almost all imbalances are speed dependent, they have a resonant frequency and come and go depending on the speed. Your vibration likely will come back at a higher speed, maybe you have just not hit the higher resonant speed??

Anyway, most bent wheels can be identified by eye without the need to special or fine measurement equipment. Some minor bends are harder to find than the major bend. Since it appears the problem is in the front of the car, this makes it a bit easier to check and locate problems. Most bends are usually on the inside of the wheel as this side of the wheel is usually not as beefy as the outside of the rim.

Usually you can just jack up one side of the car at a time. Enough to get the tire off the ground. You spin the wheel and watch in one location the edge of the rim and see if you can visually see any variation in the edge of the rim. Try this from the outside of the wheel first, then do the same for the inside of the wheel. If you have a hard time, get something stationary to put up close to the wheel likely a scrap of wood, a spray can or anything you can use that will stay stationary. Then watch carefully.

The next test it to either put a piece of scape wood directly under the tire tread or just use the pavement as a reference. Then lower the tire tread withing about 1/8" of the wood or pavement and spin the tire while watching the distance between the tire and the scrap of wood or pavement. If you see any significant variation in this distance you likely have a bent wheel. Usually bent wheels will give low spots at the tread line. This will be VERY obvious. I have seen low spots of close to 1/2" an inch before!

The last thing to watch for is tread roll. While spinning the tire, look directly at the tread from the front of the car. Watch the tread pattern carefully and watch for any unusual side to side variation of the tread pattern or any rolling of the tread pattern either on the inside or outside edge of the tire tread. Sometime this may be just a subtle tread roll or variation, but you will likely see differences between a good and bad tire/wheel combination.

The bottom line is any unusual variation in the side to side movement of a wheel or tire and any unusual variation of up and down movement of the tire tread are indication of a problem, usually with the wheel, but it could also be a problem tire.

Tires are consumable, so the will get changed/replaced at some point, wheels are not usually consumable, but they get quite a beating with the low profile tires and the lighter the wheel, the easier is bends.

You could also rotate the tires front to back as a test. I would rotate only side at a time as this helps narrow down exactly what wheel/tire is a problem.

Also keep in mind the best tire balancing will not correct for a bad wheel or tire. The tire balancer can make the tire balanced, but it cannot correct for something that is out of round, just out of balance due to a weight distribution issue. I have personally seen even the Hunter Road Force Balancer display zero weight required on a tire/wheel that had a bend that caused a vibration. A VERY good tire tech using a very unconventional method on the Hunter Road Force balancer can identify a bent wheel, but unfortunately the Hunter Road Force machine by itself cannot flag a bent wheel. This has to be up to a VERY observant tire tech and most tire techs do not pay enough attention to wheel and rim problems.

I have dealt with 8-10 bent rims over the years and I am now VERY good at identifying and flagging bent rims. Sometimes I find them when I am not even looking for them and do not even realize I had a problem!

If it turns out you do not have a wheel/tire issue, then you need to start inspecting your brakes and suspension closer, but problem wheels and tires are a far bigger issue and they do get overlooked ALL the time. Do not rely on the tire techs to pinpoint and solve these problems, you have to find them yourself.
Thanks man, so check for the wheel and then balance it


Sent from BimmerApp mobile app
 

·
Premium Member
Joined
·
28,968 Posts
Thanks man, so check for the wheel and then balance it
This is the simple answer, but even if you do not find a visual problem with the wheels, the person balancing the wheels needs to really know what they are doing to identify a wheel problem. Unfortunately the tire balancers do not really check the wheels automatically and it is up to the tire tech to find problem wheels. They may find a really bad wheel, but a slightly bent wheel may be missed.

Also just because the wheel/tire balances to a zero weight, does not mean everything is 100% straight and really will turn evenly.
 

·
Registered
Joined
·
10,678 Posts
So I got new bushings and now the left front wheel is vibrating a bit, is it the ball joints? Replace the control arm? The steering coupler? Wheel balance? Alignment? Any thoughts?

Happens around 40-65 feel it around 30 too

Sent from BimmerApp mobile app
I recommend that LCAs and LCABs be replaced as a set. Your new bushings may be exacerbating worn ball joints.


Sent from BimmerApp mobile app
 

·
Registered
Joined
·
457 Posts
Discussion Starter #11
I recommend that LCAs and LCABs be replaced as a set. Your new bushings may be exacerbating worn ball joints.


Sent from BimmerApp mobile app
And the ball joints are on the control arm itself right? And do new control arms come with the LCAB's?


Sent from BimmerApp mobile app
 

·
Registered
Joined
·
1,646 Posts
And the ball joints are on the control arm itself right? And do new control arms come with the LCAB's?

Sent from BimmerApp mobile app

Yes ball joints are on the ctl arm but you must order LCABS separately.

Once you rule out tire and wheel issues, checking for a sticky caliper is easy. Next time you have the vibration pull over somewhere safe and check each wheel. If one seems warmer it likely is the problem.
 
1 - 13 of 13 Posts
Top