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Discussion Starter #1
When Im driving the car feels ok considering I need tyres... Just a slight wheel vivration at around 65mph.. The problem is when I begin to stop.. When I begin to brake the steering wheel shakes crazy and as I apply more pressure it smooths out.. What is this ? :confused: Im about to fork out $275 per tyre please tell me its not gonna be expensive to fix this too grrrrrrr
 
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atlantisvip said:
When Im driving the car feels ok considering I need tyres... Just a slight wheel vivration at around 65mph.. The problem is when I begin to stop.. When I begin to brake the steering wheel shakes crazy and as I apply more pressure it smooths out.. What is this ? :confused: Im about to fork out $275 per tyre please tell me its not gonna be expensive to fix this too grrrrrrr
Sounds like a problem with your brakes. What you are describing sounds exactly like what one gets when there is a layer of uneven brake-pad deposits on the surface of the brake rotors. The vibration is from the brake pistons clamping down on the uneven surface of the rotor. When you apply significant force, you are less likely to feel the vibration/shudder, as the pistons are eating into the uneven brake deposits. The best solution here is to bed-in the brakes. You can visit www.zeckhausen.com for detailed instructions on how to do this. You may need to purchase a set of coarse brake pads to help remove the old pad deposits, and then switch back to the older pads. Also, your rotors may have been damaged/warped by what has happened.

It does not seem to a problem related to your tires, so I would wait before buying new ones.

Cheers, Daniel.
 

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Discussion Starter #3
The only reason I did not suspect a brake related issue is the fact that I feel no "kick Back" on the brake pedal or anything else for that matter.. But You guys definately know more about these things than I do..

As for the tyres, I do need them.. Mine are all cracked from the insides.. Strange, Ive never seen such bad tyre cracks on any of my vehicles before.. They run from the rim out towards the top of the tyres..

Thanks for the response, Really appreciate it.
 
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atlantisvip said:
The only reason I did not suspect a brake related issue is the fact that I feel no "kick Back" on the brake pedal or anything else for that matter.. But You guys definately know more about these things than I do..

As for the tyres, I do need them.. Mine are all cracked from the insides.. Strange, Ive never seen such bad tyre cracks on any of my vehicles before.. They run from the rim out towards the top of the tyres..

Thanks for the response, Really appreciate it.
Are you running Bridgestone S-03 tires? If yes, there seems to be a known manufacturer's defect that leads to severe cracking.

Regarding the brakes; you should not feel much feedback from the brakes, you will feel it in the steering wheel. I speak from personal experience at Laguna Seca.

Cheers, Daniel.
 

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actually this problem sounds to be past just plain rotor deposit, it sounds as if the deposits have gotten so bad they heated up the rotors and now they are warped.

Pad deposit causes some slight to medium shaking but a warped rotor generally causes the violent shaking hes talking about.

Ive had the same problem...had to replace my rotors. Started with hot spots, from improper pad deposit, but then got worse.
 

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Also it is imparative to torque the lug bolts/nuts to the proper spec. and in an alternating pattern. Uneven torque and excessive heat will warp the rotors! :byee55amg
 

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Discussion Starter #7
You know what, I had my front wheels balanced at some rinky dink place that had to remove the lugs by hand because they're impact wrench did not have enough torque to take them off.. They then used the same impact gun to tighten the bolts back.. So my guess is they did not over but under tighten.. Could this cause issues ? Also its strange because sometimes the vibration is not as bad.. But if I briefly go over bumps or bad roads and back on to smooth highway the vibration gets bad again.. Like something gets loosened up or something.. Im still looking for a good deal on the tires so that will be my starting point on diagnosing this issue.:M5launch:
 

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Here is something to try to determine if your rotors are in fact warpped. Get your car up on jack stands (front wheels up then the back) or a lift to get the whole car up. Slowly rotate the wheel, you should hear a slight constant drag of the brake pads rubbing on the rotor. If the rubbing sound goes away briefly and comes back at the same point on the wheel - you have warpage ouich . Check all wheels, if the sound/amount of drag is constant, your rotors should be fine. Drilled rotors should not be cut as the chamfer of the drilled holes is reduced or removed which can lead to cracking of the rotor. Be safe and replace. Im my 993 Porsche, I was getting modulation in the brake peddle and sterring wheel while applying the beakes. Turned out that both of the rear rotors were bad.
Good Luck!! :thumbsup:
 

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Also, check the front control arm bushings. On older BMWs a shaking at 65 MPH that dramatically increases in severity when braking is often due to worn out control arm bushings.

I haven't heard of this happening much yet on our Beasts, but on e28, e24, and e32 cars this is very common on high mileage cars.
 

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Louv is correct. I have severe vibrations at 61k miles. Changed the thrust bushings and it's now much better. Still slight shimmy and I suspect rotor hot spots. Installed Axxis Delux pads but never had a chance to sest them. Darned MAFS induced power lost and SES lights on hard accelerations. Just changed the MAF last Wednesday and the SES returned on Thursday. Can't get car in until early next week. This is getting to wear on me. :(

CP
 

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Discussion Starter #11
Thanks a million for the tips and advice guys. Im getting the tires replaced this week (hopefully) so while its on the lift I'll check everyting out. Im starting to suspect bushings... Its just too strange that sometimes it will shake bad and sometimes it'll be slight.. We'll see what gives soon..:(
 
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