Mack RM recalls by model year

Reported: 1977-10-12 (October 12, 1977) · Model years: 1972, 1973, 1974, 1975, 1976, 1977

THE FLEX BLADE FANS ON THE INVOLVED VEHICLES MAY DEVELOP CRACKS IN THE LAMINATED STIFFENER AS A RESULT OF FATIGUE DURING OPERATION. IF SUCH A CONDITION EXISTS AND THE CRACKS GO UNDETECTED, CONTINUED OPERATION COULD CAUSE PIECES OF THE STIFFENER TO BREAK OFF.

Remedy: DEALER WILL REPLACE THE ORIGINAL FAN WITH A STEEL FIXED BLADE FAN, FREE OF CHARGE.

Reported: 1975-10-31 (October 31, 1975) · Model years: 1974, 1975

Reported: 1978-04-04 (April 4, 1978) · Model years: 1974, 1975, 1976

AN AXLE "NO BRAKE" CONDITION COULD RESULT FROM AN EATON CONTROLLER INTERNAL ELECTRICAL MALFUNCTION. THIS CONDITION MAY CAUSE THE ANTI-WHEEL LOCK VALVE SOLENOID TO BE CONTINUOUSLY ENERGIZED AND PREVENT THE BRAKES FROM BEING APPLIED ON ONE OF THE AXLES. AS A RESULT, THE ANTI-WHEEL LOCK WARNING LAMP IS NOT ACTIVATED.

Remedy: THE DEALER WILL INSPECT AND, IF NECESSARY, REPLACE THE ANTI-WHEEL LOCK CONTROLLER WITHOUT CHARGE TO OWNER.

Reported: 1976-07-28 (July 28, 1976) · Model years: 1976

Reported: 1977-06-17 (June 17, 1977) · Model years: 1977

THE FRONT WHEEL RIM CLAMP STUDS, INSTALLED ON THE INVOLVED VEHICLES, MAY NOT HAVE BEEN MANUFACTURED CORRECTLY, CAUSING A BRITTLE CONDITION IN THE THREAD ROOT AREA. THE STUDS COULD EVENTUALLY CRACK AND BREAK WHEN WHEEL NUTS ARE TIGHTENED TO SPECIFICATIONS.

Remedy: THE DEALER WILL REPLACE ALL SUSPECT FRONT WHEEL STUDS, WITHOUT CHARGE TO OWNER.

Reported: 1977-10-12 (October 12, 1977) · Model years: 1977

THE INVOLVED VEHICLES DO NOT CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 209, "SEATBELT ASSEMBLIES". ALTHOUGH THE SEATBELTS IN QUESTION PERFORMED MARGINALLY WITH RESPECT TO THE 5000 LB. LOAD REQUIREMENT, ADDITIONAL TESTING CONFIRMED THAT THE ANCHOR COULD FAIL, ALLOWING EITHER THE ANCHOR TO SLIP OVER THE HOLD-DOWN NUT OR THE ANCHOR TO SEPARATE INTO TWO PIECES.

Remedy: DEALER WILL INSPECT AND, IF NECESSARY, REPLACE SEAT BELT ASSEMBLIES WITHOUT CHARGE TO OWNER.

Reported: 1977-11-21 (November 21, 1977) · Model years: 1977

A DEFICIENCY EXISTS IN THE WELDS SECURING THE REAR SPRING INSULATOR BRACKET TO THE AXLE HOUSING. THIS IS DUE TO IMPROPER POSITIONING OF THE WELD, IN RELATIONSHIP TO THE BRACKET AND AXLE HOUSING. FAILURE OF THE WELDS WOULD CAUSE SEPARATION OF THE SPRING INSULATOR BRACKET AND THE AXLE HOUSING, RESULTING IN IMPROPER ALIGNMENT OF THE AFFECTED AXLE.

Remedy: DEALER WILL REWELD THE INSULATOR SPRING BRACKET AT NO COST TO OWNER.

Reported: 1978-10-03 (October 3, 1978) · Model years: 1977, 1978

DELAYS OF UP TO ABOUT 2 SECONDS MAY EXIST IN THE BRAKE APPLICATION TIMES TO THE BRAKES ON THE BOGIE AXLES IN THE PRESENCE OF CERTAIN TYPES OF WHEEL SPEED SENSOR SIGNAL DISCONTINUITIES OR DISTORTIONS THAT MAY OCCUR AS A RESULT OF SENSOR WIRE FAILURE. THIS CONSTITUTES A NON-COMPLIANCE TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 121, "AIR BRAKE SYSTEMS".

Remedy: DEALER WILL INSTALL NEW WHEEL SPEED SENSORS THAT INCORPORATE IMPROVED WIRING AND THE PRESENT BOGIE ANTI-WHEEL LOCK SYSTEM WILL BE CHANGED TO AN AXLE-TO-AXLE SYSTEM FOR IMPROVED RELIABILITY.

Reported: 1979-05-31 (May 31, 1979) · Model years: 1977, 1978, 1979

IN THE EVENT OF TURBOCHARGER COMPRESSOR WHEEL FAILURE, ONE OR MORE OF THE FOUR CAPSCREWS THAT HOLD THE TURBOCHARGER TOGETHER MAY BE STRUCK BY PARTS OF THE COMPRESSOR WHEEL, RESULTING IN THE CAPSCREWS BEING DAMAGED. IF THESE CAPSCREWS ARE DAMAGED TO THE POINT THAT THEY ALLOW THE COMPRESSOR BACK PLATE TO DISLOCATE FROM THE TURBOCHARGER BEARING HOUSING, ENGINE LUBRICATING OIL MAY BE ALLOWED TO ESCAPE UNDER PRESSURE, CONTACTING THE ENGINE EXHAUST MANIFOLD SECTIONS OR TURBOCHARGER TURBINE HOUSING.

Remedy: DEALER WILL INSTALL A SHIELD FOR THE HEADS OF THE FOUR CAPSCREWS, ALONG WITH STRONGER SAE 8 GRADE 8 CAPSCREWS, IF NECESSARY, AT NO COST TO OWNER.

Reported: 1979-07-12 (July 12, 1979) · Model years: 1979

THE SPRING SEAT PLATE, LOCATED BETWEEN THE AXLE HOUSING AND THE SUSPENSION SPRINGS, MAY DEFORM DUE TO SPRING BENDING. AS A RESULT, THE CLAMPING FORCE IN THE ASSEMBLY MAY BE REDUCED. LOSS OF CLAMPING FORCE COULD CAUSE SPRING FAILURE AND THE AXLE WILL DISLOCATE. ALSO, THE TIRE COULD COME INTO CONTACT WITH THE SPRING.

Remedy: THE DEALER WILL REPLACE THE EXISTING SPRING SEAT WITH A NEWLY FABRICATED SEAT WHICH IS WELDED TO THE HOUSING. AN IMPROVED SPRING CLAMPING PLATE AND NEW SPRINGS WILL ALSO BE INSTALLED WITHOUT CHARGE.

Reported: 1990-02-23 (February 23, 1990) · Model years: 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988

CRACK MAY DEVELOP ON STEERING ARM THAT COULD PROGRESS AND REDUCE THE FATIGUE LIFE OF THE STEERING ARM.

Consequence: STEERING ARM COULD FAIL WITHOUT WARNING RESULTING IN LOSS OF STEERING CONTROL AND POSSIBLY A CRASH.

Remedy: INSTALL A REDESIGNED STEERING ARM.

Reported: 1988-03-28 (March 28, 1988) · Model years: 1986, 1987, 1988

THE STEERING SHAFT SPLINE ENGAGEMENT IS ONLY .52, THE RECOMMENDED ENGAGEMENT IS 2 INCHES.

Consequence: UNDER IMPACTS SUCH AS ROAD POTHOLES, IT COULD RESULT INSHAFT DISENGAGEMENT. THE DRIVER WOULD IMMEDIATELY LOSE STEERING CONTROLWITHOUT WARNING AND VEHICLE CRASH COULD OCCUR.

Remedy: REPLACE SHAFTS THAT MEASURE UNDER THE MINIMUM ENGAGEMENT DIMENSIONS WITH A LONGER SHAFT.

Reported: 1994-02-15 (February 15, 1994) · Model years: 1987, 1988, 1989, 1990, 1991, 1992

FUEL INJECTION SYSTEM RECONFIGURATION TO COMPLY WITH ENGINE EMISSION STANDARDS CAUSE HIGHER ENGINE VIBRATION LEVELS WHICH LEAD TO EARLY WEAR AND COMPLETE FAILURE OF THE SECONDARY THROTTLE RETURN MECHANISM.

Consequence: IN THE EVENT THE PRIMARY THROTTLE RETURN FAILS, FAILURE OF THE SECONDARY THROTTLE RETURN SYSTEM WOULD NOT PROVIDE PROTECTION AGAINST LOSS OF THROTTLE CONTROL.

Remedy: A NEW PRODUCTION SECONDARY THROTTLE RETURN SYSTEM CONFIGURATION WILL BE INSTALLED.

Reported: 1990-03-16 (March 16, 1990) · Model years: 1989

A TOLERANCE MISMATCH IN THE CRANK ASSEMBLY OF THE BOSCH WINDSHIELD WIPER MOTOR COULD CAUSE INSTANTANEOUS SEPARATION OF THE CRANK FROM THE LINKAGE ASSEMBLY IN THE LEFT HAND CONTROL ARM ASSEMBLY; THIS WOULD MAKE THE SYSTEM INOPERABLE.

Consequence: WIPER FAILURE DURING VEHICLE OPERATION COULD REDUCE DRIVER'S ABILITY TO SEE THE ROAD, AND CREATES A POTENTIAL FOR AN ACCIDENT.

Remedy: REPLACE LEFT HAND CONTROL ARM LINKAGE ASSEMBLY.

Reported: 1993-02-16 (February 16, 1993) · Model years: 1992, 1993

THE CARRIER YOKE BOLTS WERE MANUFACTURED WITH WORN ROLLING THREAD DIES, CAUSING STRESS CONCENTRATIONS WHICH CAUSED CRACKS DURING THE QUENCHING PROCESS.

Consequence: THIS CONDITION CAN CAUSE BOLT FAILURE AND ALLOW THEDRIVELINE TO SEPARATE FROM THE CARRIER ASSEMBLY.

Remedy: REPLACE THE CARRIER YOKE BOLTS.