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Brake Induced Vibration



Here is a Technical Service Bulletin I was able to get a hold of that
should be of general interest as it applies to ALL models.  I happen to be
having this exact problem.  Anyway when I get more info on
how/where/when/if we can get all of these I will post the info. here.

Bulletin Number
34 02 93 (3855)

Woodcliff Lake, NJ
March 1994
Product Engineering

This bulletin supersedes S.I. 34 02 93 (3855) dated January 1994. It
provides revised rear pad application information on the attachment. Please
remove S.I. 34 02 93 (3855) dated January 1994 from your S.I. binder and
discard.

SUBJECT: Brake Induced Vibration Felt in Steering Wheel

MODELS:
A11 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, without
causin~ problems such as rapid wear, brake dust, and noise that are often
associated with softer compound pads.

The new style pads have been phased into production approximately as follows:

E36
E34 M60
E32 M60

5/93
3/93
9/93

The E34 M50 will be phased into production in the near future. 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.

<Part number list not included.>

The list gives the part numbers of the latest compound brake pads for both
front and rear axles; however, 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. When the vehicle eventually requires replacement of the rear
pads, the pads listed should be installed so that front and rear pads both
match latest recommendations.

NOTE: The newer composition pads can be installed on the front axle while
leaving the Jurid 506 pads on the rear axle. However, newer composition
rear pads should never be installed on the rear axle while leaving Jurid
506 pads on the front axle, as this could cause premature ABS activation
under certain conditions.

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 E36 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.


Jimmy Shrake
Current: '93 318is
Previous: '85 325e (150k)

jim@domain.elided