# Replaced 10piece front suspension E34 94 540i, still vibration?



## kdog03 (Sep 26, 2006)

Here is what the problem is. It***8217;s a 1994 540i bad front end vibration at 50-60mph. Car has 185,000.

Clue 1: Vibration was getting very bad after 15" oem wheels were remounted once after I had the car for about 2 months. I lessened the vibration by examining and re-torqueing the nuts down to proper spec. I sheared a nut adapter off the torque wrench when I tried to loosen the nuts from the brake shop. They were tighter than 250lbs. When I tightened them down properly, the shimmy was tolerable, not quite gone, you could still sense it at those speeds still.

Clue 2: When I bought 16" BMW rims with snow tires after 2 years, the vibration was back and worse than ever at 50 mph, un-drivable at this speed, I have not gone above 60. The whole front end feels like its wobbling and vibrating, almost exactly like the 15" wheels 2 years ago before I re-torqued them. I took in the car with the bad vibration to a recommended mechanic and he said I needed to replace the lower control arms and tie rods, they were very worn. I decided to replace those and the upper thrust arms (there had always been a deep clunking noise going over bumps). In addition I replaced the left and right sway bar link, idler arm, and center tie rod assembly as well.

Clue3: After the suspension replacement, I drove it down the road and the vibration is still there and just as pronounced but the vibration seems stiffer. The clunking noise is gone and the steering feels much firmer so obviously it needed some of these components. I even kept all the old parts and noticed that almost all the boots were torn and the bushings for the upper thrust arms were heavily worn. I went ahead and balanced the wheels and tires and also had them check for any bent wheels, everything was fine. I still have'nt done the wheel alignment yet becuase I am nervious more things might need to be replaced. What do I do now? I felt like I just spent a grand for no reason and I am very frustrated.

Other thoughts: The mechanic did say that the round plate above one of the shocks was a little loose and might need to be fixed after this. Also, is it possible that the one of the wheels is not flush against the hub or the hub against something else, maybe some gunk or rust, which is making the wheel wobble and making the vibration at those speeds? Is there something else causing this? Why would putting a larger rim on the car make the vibration so pronounced?


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## mytorque (Jul 24, 2008)

hi mate, i nad a the same problem was driving me nuts, being a mechanic for over 25yr i had changed everything in the front end over a few months and vibration still returned. had a few good mates that were bmw experts try as well but vibration kept coming back. finaly i removed the pitman arm and aplied some loctite to it vibration seemed to improve dramticaly ' than i tighten steering box adustment to the tight side while steering was on half lock.steering on the firm side now but hey presto. vibration at 75kmh to 85kmh has totaly gone. this is after changing control arms,thrust arms, bushings, tie rod ends. track rod. wheel bearings, strut inserts, idler arm, wheels, 3 wheel alighnments, 2 on car wheel balances, 3 off car wheel balances and 2 bmw experts. if vibration returns i will be replacing the steering box and pitman arm i am confident that was the root cause of the issue. even though after systematicaly replacing all the above parts.vibration imroved but always returned. till steering and pitman arm repair and adjustment. hope this will help


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## dannydoo (Jul 6, 2007)

I went thru the same thing.Being a mechanic myself.
In the beginning I put new rotars,then changed whole front end,wheel balances etc etc/
My front end shook so hard the tires seemed like they were gona come off @55mph
I put my old rotars on and the shimmy disapeared almost 100% I think the last of it is in my tires or struts


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## Test_Engineer (Sep 11, 2004)

Did you ask the place that check your wheels if they actually checked the rim runout? I say this, because I had/have a similar shake around 45mph. I took all the wheels off and ran them on our balancer here at work. It is a Hunter road force machine that measures the force variation. Typical practice is to run the road force procedure and if it comes out high, then you actually check the wheel runout. But if the road force is fine, you typically assume the wheel is fine. I did it this way about 6 months ago, and didn't find a problem with balance or road force. I even swapped the wheels front to back, but my vibration still remained. After replacing control arms(ball joints bushings....), Rotors and pads, I even rebuit the calipers incase they were sticking...... NOTHING helped! So after over $1,000 in parts and a lot of my time spent on this, the other day I got so pissed off, I pulled off all the wheels again, took off all the wheel weights and actually measured the wheel runout...... 2 bent wheels! The road force measurement was fine, and balance was fine, but the 2 wheels were bent to hell. One was 1.57mm and the other was 1.91mm bent. The Road force machine doesn't apply a full vehicle load, so if the tire is "worn" to the bend, it won't show up as a problem. One was on the front and one was on the back, so when I swapped front to back, the problem remained. 

If you have done a ton of work on the car to fix this and it hasn't gotten better, have the wheels checked again, and make sure they actually measure the wheel runout, and not just check it with Road Force Variation.


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