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View Full Version : The wheel balancing experience thread



J.DeFeo
07-12-2007, 09:28 AM
I've searched this forum to death and know all about the shimmy issue with the thrust arm bushings, hubcentric rings, etc. I have a slight rumble at highway speeds and I don't think it's any of these issues, and here's why:

1.) It was very bad on my old tires. I got new tires (and balancing) and the problem got better but still wasn't perfect.

2.) Feels like I'm just running on a very bumpy highway, rather than any side-to-side motion.

3.) Braking has zero effect on the rumble.

4.) It manifests around 55mph and gets a little worse all the way to about 70 mph where there is a bit of a lull. It's not really noticeable at 75 or above.

5.) I have stock wheels, so no hubcentric rings.

6.) There is no noise when going over bumps or when normally driving.

This leads me to believe that my wheels were not properly balanced by NTB. I've read about static vs. road force balancing but I'm not convinced. I've heard conflicting reports about the effect of both, as well as how sensitive the suspension in the e34 is. So I'm asking everyone, what have your experiences been with wheel balancing? I'm sure nearly all of you have had your wheel balanced at some point, so where did you get it done? What method did they use? What were the results?

For me, I got my wheel balanced at NTB when I bought Potenzo G009 tires to replace my Turanzas with 45k miles on them. The rumble greatly improved but it is still present. I've thought about taking my car to the BMW dealership, which has one of those fancy Hunter GS9700 machine to get it balanced again but I don't want to waste money if there's a cheaper, better solution.

Ross
07-12-2007, 09:36 AM
I'll wager anyone here that not only are they improperly balanced but with the wrong weights.
Go anywhere but NTB.

Mitch90535im
07-12-2007, 09:38 AM
I had similar symptons and discovered a bent wheel the last time I took mine for a re-balancing.

J.DeFeo
07-12-2007, 09:45 AM
I'll wager anyone here that not only are they improperly balanced but with the wrong weights.
Go anywhere but NTB.

What do you mean the wrong weights? Is there a way to check this?

bsell
07-12-2007, 11:04 AM
What do you mean the wrong weights? Is there a way to check this?

It could be the tech put on a weight that differs from what the machine called for. Or they were put in the wrong places.

How fast did they spin the wheels/tires? The local guy (Rico) I use uses a machine that has no motor to spin the wheels/tires. He has to give them a spin, then the machine figures out the weights needed. The motor-less theory is that motors induce vibration and thus error into the balance equation and a motor-less rig is more accurate.

Rico uses weights that stick to the inner center (flat) part of the wheel and cuts the weights to spec rather than using the closest weight available.

He did a great job smoothing out my lopsided tire (from bad arms), even at speeds over 100mph. The guy that changed the arms 'balanced' my right side wheels to my chagrin as now I have the 'wookies' on the right side from 60-75 mph, a range I drive through twice a day.

I've been too lazy/busy to get by Rico's to get my right sides fixed as the wookies aren't too bad and the tires should be shaved to make them round again anyway. I could replace them but they have a year or more of wear left and I hate to throw 235/45/18's (91W) away at the drop of a hat...

My suggestion is to find somebody that gives a damn about doing the job right and pay them to protect your new tire investment. It sucks you have to spend the money twice but it will be cheaper in the end (over replacing your newly cupped tires).

Brian

J.DeFeo
07-12-2007, 11:22 AM
It could be the tech put on a weight that differs from what the machine called for. Or they were put in the wrong places.

How fast did they spin the wheels/tires? The local guy (Rico) I use uses a machine that has no motor to spin the wheels/tires. He has to give them a spin, then the machine figures out the weights needed. The motor-less theory is that motors induce vibration and thus error into the balance equation and a motor-less rig is more accurate.

Rico uses weights that stick to the inner center (flat) part of the wheel and cuts the weights to spec rather than using the closest weight available.

He did a great job smoothing out my lopsided tire (from bad arms), even at speeds over 100mph. The guy that changed the arms 'balanced' my right side wheels to my chagrin as now I have the 'wookies' on the right side from 60-75 mph, a range I drive through twice a day.

I've been too lazy/busy to get by Rico's to get my right sides fixed as the wookies aren't too bad and the tires should be shaved to make them round again anyway. I could replace them but they have a year or more of wear left and I hate to throw 235/45/18's (91W) away at the drop of a hat...

My suggestion is to find somebody that gives a damn about doing the job right and pay them to protect your new tire investment. It sucks you have to spend the money twice but it will be cheaper in the end (over replacing your newly cupped tires).

Brian

Good post. Does anyone have a recommendation for a place in or around Worcester, MA?

Tiger
07-12-2007, 11:29 AM
I have ton of experience on wheel balancing... I actually do my own wheel mount and balancing. I find alot of time at general tire store is that they don't calibrate their tire balancer regularly... which goes off when they do volume work.

A few things you can look for yourself...

1. How much weight is installed on your wheel

2. What is the location of where they put it on... like hammer on weights on inside and outside... or stick on in the middle of tire only.

3. If you want to verify if your wheels are straight then jack up the car... put a stationary object near the tire and maybe a rod to get closer to the wheel and spin it... to see if the wheel goes in and out as in bent...

Another bent wheel is look at the wheel to see if you got 'flattened part of the wheel" where it is supposed to be round.

Tiger
07-12-2007, 11:31 AM
In your case, I highly suspected your upper control arm is shot... if not the bushing then the ball joint on the thrust arm. The symptom you have is classic thrust arm bushing torn.

At 55MPH or 60MPH... what happens if you hit the brake at that speed? Does it feels like your front end will all fall apart?

You can visually look at the bushing with strong flashlight to see if you got any rip in it.

spyrot1
07-12-2007, 11:37 AM
I had the same problem... I had my wheels balanced at a local shop (or so I thought) but I still had issues at certain speeds. My winter basketweaves were fine, but my summer style 5's had issues.

Took it to a Wal-Mart and had them balance the wheels... viola! the car drives great again. And it only cost $15 to balance them... I figured $15 was good a price to pay to test the theory that the wheels were unbalanced and the previous shop either didn't know what they were doing or just didn't do it.

J.DeFeo
07-12-2007, 11:38 AM
In your case, I highly suspected your upper control arm is shot... if not the bushing then the ball joint on the thrust arm. The symptom you have is classic thrust arm bushing torn.

At 55MPH or 60MPH... what happens if you hit the brake at that speed? Does it feels like your front end will all fall apart?

You can visually look at the bushing with strong flashlight to see if you got any rip in it.

Like I said in the OP, braking has absolutely no effect at any speed (well besides slowing the car down). Thus why I don't think it's a bushing issue. Also, I believe the thrust arm issue only manifests between 50-60 MPH, and once you get above 60MPH is not noticable. This is noticeable all the way up to 75 MPH which just screams wheel balance to me.

spyrot1
07-12-2007, 11:43 AM
Like I said in the OP, braking has absolutely no effect at any speed (well besides slowing the car down). Thus why I don't think it's a bushing issue. Also, I believe the thrust arm issue only manifests between 50-60 MPH, and once you get above 60MPH is not noticable. This is noticeable all the way up to 75 MPH which just screams wheel balance to me.

My balance problem showed itself at 65mph and 85mph... and this was after I replaced the thrust arms with new Lemforders with the 750 bushings.

BMWCCA1
07-12-2007, 11:57 AM
Balancing is a combination of the machine and knowing WTF you're doing. I'm happy to pay a shop their going rate for balancing if they'd just let me do the labor myself. Here's a shot from my 318ti recent tire installation done at a local Tire Rack Recommended Installer (HAH!). I've never seen anything like this. Thankfully they're currently on the rear of the car. Check out the number, mix, and location of the weights, especially the stick-ons on the lateral surface!:
http://i31.photobucket.com/albums/c378/BMWCCA1/DSC_0233.jpg

Tiger
07-12-2007, 12:01 PM
Then it is wheel balance issue. This is assuming your wheel is in good condition. Look at your weights... if you see like 2.5 oz on one side... on the edge of wheel (not the tape weight in center) then good possibility that your wheel is not true.

I have seen incredible amount of weight on a small 15" steel wheel... which tells me bent wheel.

The most you should see on the edge of the wheel weight is like 1.5 oz... I'd like to see all of them much lower than that... Sometime, I am stunned that I don't need any wheel weight. I'd like to see all like less than 1 oz.

Tiger
07-12-2007, 12:05 PM
Holy mackeral... That tire is balanced off a bad tire balancer... either not calibrated or bad parts inside the balancer. I have been throught that experience many times. You must have spun it like 4 times to get that balanced.

Also, the stick on, on the side of the wheel will spin off the wheel... it would never hold.

bmwrp8
07-12-2007, 12:08 PM
I had a problem before no shimmy but vibration from 55miles up...try checking your guibo and center bearing...it worked for me...http://bmwe34.net/e34main/Maintenance/Transmission/CenterBearing.htm

J.DeFeo
07-12-2007, 12:13 PM
I had a problem before no shimmy but vibration from 55miles up...try checking your guibo and center bearing...it worked for me...http://bmwe34.net/e34main/Maintenance/Transmission/CenterBearing.htm

That was my other thought but I'm replacing both of those next week so we'll see how that goes. The guibo was replaced about 21k miles ago by the previous owner.

I'm also going to check wheel roundness while I have the car up on stands and the driveshaft disconnected, but I'm pretty sure the wheels are fairly straight since I don't recall any particularly large weights on the wheel.

bmwrp8
07-12-2007, 12:28 PM
That was my other thought but I'm replacing both of those next week so we'll see how that goes. The guibo was replaced about 21k miles ago by the previous owner.

I'm also going to check wheel roundness while I have the car up on stands and the driveshaft disconnected, but I'm pretty sure the wheels are fairly straight since I don't recall any particularly large weights on the wheel.

If your center bearing was shot your guibo Might be affected even though it was replaced 21k miles earlier :) yup while at it check the roundness of your rims and tires aswell...others also your wheel bearing and rotor disks