rear-brake-spring-noise-34-013-88-2296-388

Service-InformationM otorcycle BMW NA Service Department Group: 34 . Brakes Rear Drum Brake Spring Noise – R65s, R80s – 1985 and later, and K75s March, 1988 34,013-88 2296) For USA Only Under certain circumstances a resonance of the Rear Brake Spring isaudible to the rider when brakes are applied at slower speeds. Service Information (34 011 86 [2230] January, 1987) recommends the installation of a harmonic damper (34 21 l 457 602 or 34 21 l 457 572) to minimize this noise. The rubber dampers can be installed in all model motorcycles with brake shoes that are 25nm wide. All Boxer models starting with model year 1985 All R80G/S and R80ST models All K75s with drum brake However, under certain circumstances this damper may not be a complete solution. In these cases we recommend the installation of updated brake shoes: 34 21 1 242 401 – Upper Brake Shoe 34 21 1 242 402 – Lower Brake Shoe These shoes have relocated spring attachment points, that produce more spring pressure on the damping block. Brake shoes which have the relocated spring attachment points are identifiable by a cast-in stamp. The ten (10) dots surrounding the “86” in the stamp indicate October, 1986. The spring tension is similar between sand (1986) and die (1987) cast shoes for K75 models. Only reolace shoes if noise persists after the rubber damper is installed. ( ( Important Note: Always renew brake springs, as prolonged exposure to ( Warranty Status: Very truly yours, harmonic vibration could result in spring failure. Relocated Spring Attachment Point Parts and Labor are reimbursable under the prov1s1ons of the BMWLi mited Motorcycle Warranty of three (3) years/unlimited miles, using a normal warranty claim form. BMW of North America, Inc. Frank Stevens National Service Manager Richard Dampf Natior.al Technical Manager FS :jel/492.2 • I