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View Full Version : Do these symptoms sound like worn/loose thrust arm bushings?



AllanS
05-10-2004, 12:10 PM
Lately, i've been getting the shakes again, from 45-60mph. The steering shakes badly when hitting small, frequent bumps, especially while turning, and there a clanging, vibration like noise on said small bumps, usually audible from the right hand side at lower speeds.

I gave everything a cursory checkout last week, and nothing was loose, or looked like it might be trouble, but when I changed the thrust arms last time (750 arms), I didn't torque the bolts under full load, but simply jacked up the hub while the wheel was off. I'm thinking that this might have something to do with it, since there are no other real possibilites that I can see. Any suggestions would be great-

Thanks!
Allan

Jazzman
05-10-2004, 01:01 PM
If you did not torque the bushing bolts while down on the tires and loaded normally, you probably destroyed your new bushings. The bushing angle of play is based on the whole arm in the normal loaded position. If you tightened it down in the angle where it was jacked up you were basically trying to twist the bushing to the normal loaded angle, which unfortunately will stress it to the point of tearing. Just follow Bruno's instructions and everything will be OK. Noise when hitting a bump with followed by the shaking is normally due also to worn out ball joints.




Lately, i've been getting the shakes again, from 45-60mph. The steering shakes badly when hitting small, frequent bumps, especially while turning, and there a clanging, vibration like noise on said small bumps, usually audible from the right hand side at lower speeds.

I gave everything a cursory checkout last week, and nothing was loose, or looked like it might be trouble, but when I changed the thrust arms last time (750 arms), I didn't torque the bolts under full load, but simply jacked up the hub while the wheel was off. I'm thinking that this might have something to do with it, since there are no other real possibilites that I can see. Any suggestions would be great-

Thanks!
Allan

632 Regal
05-10-2004, 01:10 PM
yep thrust arms/ball joints possibly on the control arms also, check the steering ends good. you will get shake if anything has play including worn shocks.

AllanS
05-10-2004, 01:16 PM
Jeff, how do you tell if ball joints are worn, do they just have a lot of play in the joint itself? Do you know if it's side to side, or one particular direction?

AllanS
05-10-2004, 01:18 PM
I guess I'll be buying new thrust arms, then. 150$ is a damn expensive way to learn to follow directions properly. Would it be a good idea to swap out the control arms as well?

ryan roopnarine
05-10-2004, 01:27 PM
calipers will check the up/down play, doubt common "side to side" wear occurs, you could also check it with clay/playdough and a spark plug gauge if you don't have a caliper around.....after looking hard for wear specs, i'd say within .030 is an acceptable amount for the ball joints in the e34, even though that is more likely appropriate for an e28.....ymmv may vary with play specifications. ( i know at least one state that fails bmw 5 series for .035 and over on their MOT).


Jeff, how do you tell if ball joints are worn, do they just have a lot of play in the joint itself? Do you know if it's side to side, or one particular direction?

AllanS
05-10-2004, 01:29 PM
Thanks Ryan

AllanS
05-10-2004, 01:33 PM
Would it be logical to also change the tie rods and center tie rod while I'm down there? Is it possible that they might have been damaged as well?

Bill R.
05-10-2004, 02:04 PM
sitting on the jack, I mean you started to lift it off the jack stands then I would say the the suspension was easily loaded enough and the thrust arms are probably fine... Also checking ball joint play with calipers would be a major pain in the ass and its not likely to work very well. You would typically put a dial indicator on the joint and use a big pry bar to load/unload the joint to measure the play... I would visually inspect the thrust arm bushings and see if they are visibly damaged, if you had the suspension that far unloaded when torquing you should be able to see some tearing on bushing.... Then if that looks ok, I would check (with the car raised up and suspension unloaded) the wheel bearings, grab the tire with one hand on top of the tire and one hand on the bottom and rock it back and forth pushing with one hand and pulling with the other. IF there's play there its most likely the wheel bearings, then grab the tire at each side halfway up the tire so your hands are at equal points on the tire halfway up and push pull again... Any movement here beside actually moving the steering wheel would be worn tie rod ends or center link ball joint wear or idler arm wear... sometimes its easier if you have someone else push/pull on the sides of the tire while you look at each tierod and at the center link where it connects to the pittman arm on the steering box and at the idler arm, sometimes visible play is obvious and that could be the cause of your shaking. ... Then i would check the big nut on the strut and tighten it some with a pipe wrench to see if thats the clunking and then inspect the ball joint ends on the sway bar links... usually if you tap on the sway bar with a rubber mallet out by the links you'll hear the links rattle if the joints are bad.





Would it be logical to also change the tie rods and center tie rod while I'm down there? Is it possible that they might have been damaged as well?

AllanS
05-10-2004, 02:38 PM
You're a wealth of knowledge, thanks Bill. I'm going to try all that out tonight and see what I find. I've noticed that I can wiggle the wheel at the sides like you mention, using my feet when it's sitting on the ground as usual. If this happens while the wheel is locks or held stationary, would it be an indicator of tie rod/center link ball joint wear?

If so, would a standard array of pickle forks be good enough to get all that off in order to install new parts, or do you think a real tie rod puller would be necessary?

Thanks,
Allan

Bill R.
05-10-2004, 02:48 PM
wiggle it side to side with it up in the air...Then there are only a few things in the order that it can be... One is a certain amount of play in the steering box itself, the next is the tierods and center link joint. Then idler...I would have someone else wiggle the tire from side to side while you look from underneath on a creeper at each connection to determine where the play is....sometimes for example on the outer tie rods by the spindle you can wrap your hand around the joint and the spindle portion that it connects to.. that way you can detect movement in the joint itself ... hard for me to explain, its much easier to show you... And because you can move it with your feet while the wheel is locked wouldn't be a good indicator.. there's enough steering wheel movement when its in the locked position to make that not accurate...





You're a wealth of knowledge, thanks Bill. I'm going to try all that out tonight and see what I find. I've noticed that I can wiggle the wheel at the sides like you mention, using my feet when it's sitting on the ground as usual. If this happens while the wheel is locks or held stationary, would it be an indicator of tie rod/center link ball joint wear?

If so, would a standard array of pickle forks be good enough to get all that off in order to install new parts, or do you think a real tie rod puller would be necessary?

Thanks,
Allan

AllanS
05-10-2004, 07:15 PM
I just checked out the thrust arms, and here's what I found...

Out of the box, the bushing arrow on the green plastic is pointing at a mark on the arm itself, so it's centered in effect, as shown in the first image attached.

On my car, when jacked up and with the wheels dangling, it looks like it does in the second picture, where the arrow isn't aligned.

Do you think that this is because of how I torqued it improperly?

Paul
05-10-2004, 07:48 PM
I chased this same ghost for over a year. vibration 10 mph either side of 60. Replaced center bearing in driveline,thrust arms, tie rods,new tires,and numerous balance and alignments.Nothing made much of an improvement.
In researching what to try next, on this, the best forum on the internet, I would often find reference to a loose steering wheel shaft coupling nut. Of course this seemed too simple, so never paid much attention. Finally it got bad enough that I was able to feel a click in steering shaft. So I take the trim off , locate nut on shaft, tighten about one full turn, and car is now smooth as new..........lesson, do the easy stuff first.

Bellicose Right Winger
05-10-2004, 08:12 PM
The arrows will only be aligned when the weight of the car is on the tires. Can you see the arrow under these conditions or after you've driven it onto car ramps? If you stand on the brakes, and I mean hard but without engaging the ABS, at 30 mph or so do you hear any banging? How many miles since you changed the bushings? What's the mileage on car and have any other front suspension or steering parts been changed? Stock or aftermarket wheels? When were front tires balanced?

Paul Shovestul


I just checked out the thrust arms, and here's what I found...

Out of the box, the bushing arrow on the green plastic is pointing at a mark on the arm itself, so it's centered in effect, as shown in the first image attached.

On my car, when jacked up and with the wheels dangling, it looks like it does in the second picture, where the arrow isn't aligned.

Do you think that this is because of how I torqued it improperly?

AllanS
05-10-2004, 08:17 PM
Also, I think I narrowed that clunking/vibration down to the brake caliper. When I nudged the wheel at the sides like you said, I could hear something clanging. I had my brother step on the brake pedal while I moved the wheel and the sound went away. I also took a stethoscope and put it up to the brake caliper, control arms, tie rods, etc., and it was loudest at the caliper. He also nudged the wheel while I checked out the tie rods and control arms, and nothing was out of place.

I'm going to try going over some bumps in a crappy parking lot tomorrow and see if I can reproduce the sound, and then do it again while gently touching the brakes. The problem is that it could be 2 different noises altogether.

AllanS
05-10-2004, 08:52 PM
I'll check the position of the arrows under load tomorrow, and see if there's any banging under hard braking.

The arms are lemforder with 750il bushings, and were just put in under 5k miles ago, along with Mtech springs and sway bars. Everything functioned perfectly up until maybe 500-1000 miles ago. The car has 125k miles right now. Wheels are 17" Breyton Magics. Front brakes are single piston 850i.

I've had the front and rear balanced once right after I swapped spings, and once before this when I first bought the car. The wheels themselves were balanced when I got new tires a little while after I swapped the springs/sways/arms. It had a shimmy originally, which went away when I changed thrust arms and springs.

Thanks,
Allan

NoSpeedLimits
05-26-2004, 01:48 PM
I am currently chasing this ghost and want to check this easy item before I strain the bank account any further...or my car shakes apart -- the shimmy is getting worse by the day.

What trim do I need to remove in order to verify if my steering wheel shaft coupling nut is loose?

Sorry for dredging this old post back up to the top, but I was searching through the archives and found this thread and got excited about putting an end to my problem.

AllanS
05-26-2004, 02:18 PM
I tried messing with the steering nut under the dash, to no avail. It's as tight as it can get. Maybe you could try the other nut at the steering box itself?

NoSpeedLimits
05-26-2004, 03:01 PM
Sorry to hear...Did you need to remove any items to check the steering nut under the dash?

AllanS
05-27-2004, 07:15 AM
Yep, you need to remove the 2 trim pieces beneath and around the steering column. The one up top gets taken out first, then the bottom one. The top one is screwed in by 1 screw near the door (hard to see, half hidden), a number of screws behind the 2 wood trim pieces (which get pried off), and a couple at the bottom.

Then the black one at the bottom comes off- 2 thumbscrews hold it on at the rear where the pedals are, and a couple screws are up top. You have to sort of fanagle it out, unless you remove the black plastic duct from the top of it first.

Once it's all out, you can see the large nut on the steering shaft, and adjust it at will. I think I used a 7/8 wrench, but I'm not sure on that.