Brakes - Steering Wheel/Body Vibration
Group 34Brakes
Bulletin Number
34 O2 93 (3855)
Woodcliff Lake, NJ
July 1994
Product Engineering
This bulletin supersedes S.I. 34 02 93 (3855) dated March 1994, which should be removed from your S.I. binder and discarded. It provides revised information in the shaded areas.
SUBJECT:
Brake Induced Vibration Felt in Steering Wheel
MODELS:
All Models
Situation:
Some cars, especially those equipped with Jurid 506 brake pads, may exhibit a vibration in the body and steering while braking. When the brake discs are checked for runout, they frequently are found to be within specification.
This vibration is caused by the hard composition of the Jurid 506 pads, which amplify any variations in the brake discs, and the vibrations are transmitted into the body and steering.
New brake pad compositions have been developed and tested for various models which greatly reduce the tendency to cause vibrations.
The new style pads have been phased into production approximately as follows:
E36 5/93
E34 M50 5/94
E34 M60 3/93
E32 M60 9/93
There will be no production changes on the E31, E32-M70, or Motorsport models.
Correction:
In case of customer complaint, replace the front brake pads and discs. The list gives the part numbers of the latest compound brake pads for front axles. It is not necessary to replace the rear pads or discs to cure a vibration complaint. If the rear pads and discs currently on the car are not beyond specifications they do not have to be replaced.
Whenever pads are replaced, all metal to metal contact points of the pad and caliper should be lubricated with Plastilube, BMW part number 81 22 9 407 103.
To prevent cold brake squeal when replacing pads on the E3G models only, all edges of the front pads should be chamfered with a file, cutting in 2 mm to a depth of 3 mm. Apply Permatex Disc Brake Quiet to the back of the front pads, as per the manufacturer's instructions on the can.
Warranty Status:
Brake pads and brake discs are covered for defects in materials or workmanship by the BMW New Vehicle Limited Warranty.
Recent analysis of brake rotor claims indicate that this bulletin is being interpreted by some dealers as a field action. Please consider that:
1) The customer complaint must be for brake induced vibration with Jurid 506 pads installed hence, add-on repairs by the technician, whether approved by management or not, are ineligible.
2) The front brake motors must be above minimum thickness. Since the bulletin's repair instructions are to place rotors and Jurid 506 pads with a customer complaint of steering vibration, checking run-out is redundant and not claimable.
3) Rear brake pads and rotors do not fall under the provisions of this bulletin.
Deviations from the above procedure requires regional authorization.