OSHKOSH F 1988: SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DRUM

General Information

NHTSA Campaign ID Number: 91V187000

Make Model Year
OSHKOSH F 1988
Date Owners Notified Date Received by ODI Date Added to Database
1991-11-08 1991-10-27 1991-10-30

Production Dates: 1985-01-01 - 1991-04-01

Manufacturers Involved: Oshkosh Corporation

Component: SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DRUM

Potential Number Of Units Affected: 130

Report Initiator: MFR MFR Report

Summary

THESE VEHICLES HAVE FRONT AXLES WITH BRAKE CAM OPERATION OPPOSITE TO THE ROTATION OF THE BRAKE DRUM "CAM OPPOSITE", AND THERE IS A TENDENCY FOR BRAKES TO CHATTER UNDER LOW AIR PRESSURE, RESULTING IN VIBRATIONS. THE VIBRATIONS INDUCE STRESSES IN THE TIE ROD END BEYOND ITS ENDURANCE LIMIT, AND RESULT IN CRACKS IN THE THREADED PORTION OF THE STUD WHERE THE TUBE ENDS.

Consequence

CRACKS IN THE TIE ROD CAN RESULT IN SEPARATION OF THETIE ROD AND LOSS OF VEHICLE CONTROL WITHOUT PRIOR WARNING.

Remedy

REPLACE THE CAM OPPOSITE BRAKE ACTUATION WITH CAM SAME BRAKE OPERATION, BY INTERCHANGING THE LEFT AND RIGHT CAM ASSEMBLIES TO AVOID BRAKE CHATTERING; AND REPLACE TIE RODS.

Notes

SYSTEM: BRAKES AND FRONT SUSPENSION.VEHICLE DESCRIPTION: HEAVY TRUCKS WITH 18000 LBS. DRIVING FRONT AXLES.