2010 Mack CXU612

On October 3rd 2010 the Office of Defects Investigation (ODI) received two complaints on 2009 - 2010 Mack CXU612 and CXU trucks for failing bolts that clamp the 5th wheel to the frame of the truck. On January 19, 2011 ODI opened this Preliminary Evaluation.During the course of the investigation ODI took possession of fasteners from the field.These fasteners, taken off subject complaint vehicles, exhibited 'hourglass like stretching' indicating plastic deformation.This same source supplied ODI with new fasteners (for the subject vehicle) that were recently purchased and never used.The bolts supplied by the manufacturer are M16 x 2 Class 10.9 bolts.Per SAE J1199, these bolts should have a proof load 130 kN (~29,000 lbf) and tensile strength of 163 kN (~36,600 lbf).These bolts are not designed to be torque to yield.ODI took possession of these field samples and sent them to (VRTC) Vehicle Research and Testing Center for testing.Some of the new and used fasteners from the field were tested to the SAE J1199 standard and all passed.Other tests at VRTC indicated that the stretched bolts were likely the result of over torque during installation or maintenance.VRTC tested other methods to pre-tension the bolts and found that load indicating washers and turn-of-the-nut method both gave better clamping load control than a torque wrench.In February 2011 Mack started to perform field inspections associated with this investigation in an attempt to understand the cause of the bolt failures.During these inspections, Mack discovered that there was an interference with the bolts used to secure the fifth wheel to the frame.This interference can prevent the bolts from being torqued to specification.If this occurs, the bolt(s) may fail and in extreme cases may result in the fifth wheel coming loose causing the trainer to separate from the tractor.Mack has issued a voluntary Safety Recall 11V-209 for (failure of fifth wheel mounting bolts). However, claims in the field suggest the manufactured supplied fasteners are inferior and stretch regardless of interference.ODI will continue to monitor this issue and follow the completion progress.If failures continue, ODI may open another investigation to investigate future failures.Mack Truck's recall action resolves the issues raised by this investigation and, therefore, this investigation is closed.

THE 5TH WHEEL MOUNT BOLTS ON MY COMPANY'S 2010 AND 2009 MACK TRUCKS ARE STRETCHING AND BECOMING LOOSE. I SAW UNIT 10101 ON SUNDAY, 20 MARCH 2011 ON OUR YARD READY TO HOOK UP. I HAD FINISHED MY SHIFT AND WAS WALKING PAST THE UNIT WHEN I REACHED OUT AND TURNED THE BOLT BY HAND. *TR

NHTSA ID

10392537

Incident

Mar 20, 2011

Mileage

150,000 mi

I AM A MECHANIC FOR A LARGE TRUCKING FIRM. I HAVE BEEN COMPLAINING ABOUT THE 5TH WHEEL BOLTS ON OUR 2008, 2009, AND 2010 MACK TRUCKS FOR TWO YEARS NOW. THE COMPANY HAS YET TO IMPLEMENT A PROGRAM TO CORRECT THIS MATTER, INSTEAD CHOOSING TO THREATEN ME WITH DISCIPLINARY ACTION FOR POINTING OUT LOOSE BOLTS ON OUR ROAD TRACTORS. TODAY (03/15/2011) I PASSED A 2010 TRACTOR ON THE READY LINE. IT WAS UNIT #10289 WITH ONLY 76327 MILES ON IT. THE 5TH WHEEL PLATE HAD BEEN SHIFTING ON THE FRAME AND ALL OF THE FASTENING BOLTS WERE RUSTY. THE TWO BOLTS THAT I CHECKED TURNED EASILY BY HAND - RATTLING LOOSE. THE BOLTS WERE NOT HITTING ANY THING THAT MIGHT HAVE LOOSENED THEM, THEY HAD STRETCHED. THE SHOP FOREMAN ON DUTY WAS THE ONE WHO HAD TOLD ME THAT I WAS "OUT OF LINE" TO LOOK AT TRUCKS THAT I DID NOT HAVE A WORK ORDER ON, SO I DID NOT RISK TELLING HIM. THE HEAD OF OUR SAFETY DEPARTMENT AT THE GENERAL OFFICE HAD TOLD ME THAT "THE COMPANY IS HANDLING IT AND FOR ME TO LEAVE IT ALONE" SO I AM REPORTING IT TO THE ODI. THE 5TH WHEEL BOLTS ARE LOOSE. *TR

NHTSA ID

10390328

Incident

Mar 15, 2011

Mileage

76,327 mi

MACK HAS BEEN SELLING OVER THE ROAD TRUCKS WITH SUBSTANDARD BOLTS HOLDING THE 5TH WHEEL TO THE FRAME. AS A MECHANIC WITH ABF, I AM SEEING TRUCKS EVERY DAY WITH 5TH WHEELS THAT ARE LOOSE. ON 22 SEPTEMBER 2010, I WORKED ON UNIT #10222 AT THE LITTLE ROCK SHOP. THIS TRUCK HAD ONLY 4376 MILES ON IT AND I COULD TURN THE 5TH WHEEL BOLTS WITH ONE HAND USING A 10 INCH COMBINATION WRENCH. I TRIED TO TORQUE THE BOLTS TO SPECS, BUT THEY ONLY STRETCHED. I REPLACED THE BOLTS WITH AFTERMARKET BOLTS WHICH TIGHTENED NORMALLY. *TR

NHTSA ID

10358965

Incident

Sep 22, 2010

Mileage

4,376 mi

AS A MECHANIC CONTRACTED TO MAINTAIN ABF ROAD TRACTORS, I WORKED ON UNIT 10064 ON 9/22/2010. I DISCOVERED THAT THE 5TH WHEEL MOUNT BOLTS WERE ALL LOOSE. THIS TRUCK HAD ONLY 51,285 MILES OF SERVICE PULLING PUP TRAILERS! I REMOVED THE BOLTS TO MAKE SURE THERE WAS NO THREAD DAMAGE, LIGHTLY OILED THEM, AND ATTEMPTED TO TORQUE THEM TO MACK SPECS OF 235 FT.LBS. TORQUE. NONE OF THE BOLTS WOULD TIGHTEN PROPERLY, ALL OF THEM STRETCHED. I REPLACED ALL OF THE BOLTS AND TAGGED THE DEFECTIVE BOLTS FOR MACK WARRANTY. AS A CITIZEN WHO EXPECTS THE HIGHWAYS OF THE UNITED STATES TO BE SAFE FOR TRAVEL, I AM ASKING THE ODI TO FIND OUT WHY ALL OF THE MACKS DELIVERED TO ABF HAVE DEFECTIVE 5TH WHEEL MOUNT BOLTS AND TO FIND OUT IF THE MACKS DELIVERED TO MORE DEMANDING CUSTOMERS ( SUCH AS LOGGERS, GRAVEL TRUCKS, CONCRETE TRUCKS, AND TANDEM AXLE FULL TRAILER LOAD TRUCKERS ) ARE ALSO ASSEMBLED WITH INFERIOR QUALITY FASTENERS THAT FAIL PREMATURELY. *TR

NHTSA ID

10357085

Incident

Sep 22, 2010

Mileage

51,285 mi

I AM A MECHANIC FOR ABF FREIGHT SYSTEM. I HAVE OBSERVED THAT MANY OF THE MACK TRUCKS WE USE IN OUR ROAD FLEET HAVE PREMATURE FAILURE OF THE FASTENERS HOLDING THE 5TH WHEEL COUPLER TO THE TRUCK FRAME. I WORKED ON UNIT 10016 ON 9/21/2010 AND CHECKED THE 5TH WHEEL BOLT TIGHTNESS AS A FOLLOW UP TO COMPLAINT #10356665. THE BOLTS WERE LOOSE AFTER ONLY 63,450 MILES OF SERVICE. I TRIED TO TIGHTEN THEM AS I HAD PREVIOUSLY BEEN ORDERED TO DO BUT THE BOLTS ONLY STRETCHED. I REPLACED THE 5TH WHEEL BOLTS. THE OLD BOLTS THAT HAD BEEN TIGHTENED WERE VISIBLY STRETCHED. *TR

NHTSA ID

10356871

Incident

Sep 21, 2010

Mileage

63,450 mi

I AM A MECHANIC FOR ABF. FOR THE LAST THREE YEARS, MACK HAS SOLD TO ABF ROAD TRACTORS WITH DEFECTIVE 5TH WHEEL MOUNTING BOLTS. THE BOLTS STRETCH AND BECOME LOOSE WITH USE (USUALLY WITHIN THE FIRST 30,000 MILES). FOR UNKNOWN REASONS ABF HAS NEVER HELD MACK ACCOUNTABLE FOR THIS PROBLEM, PREFERRING TO TIGHTEN THE BOLTS WHEN A DRIVER COMPLAINS AND REPLACING BOLTS WHEN THEY PULL IN TWO. I HAVE REPEATEDLY WARNED MY SUPERVISORS THAT THESE BOLTS SHOULD BE REPLACED RATHER THAN REPEATEDLY RETORQUED, BUT HAVE BEEN REBUFFED DUE TO MANAGEMENT DISTRUST OF UNION EMPLOYEES. NOW OUR 2010 MODEL TRUCKS ARE GETTING 20-50K MILES ON THEM AND I AM SEEING NEARLY 100% WITH LOOSE 5TH WHEEL MOUNT BOLTS. WE PURCHASED REPLACEMENT BOLTS FROM MACK AND DISCOVERED THAT THEY WOULD NOT TAKE THE TORQUE SPEC THAT MACK GAVE US, THEY SIMPLY STRETCHED UNTIL THE CROSS SECTIONAL AREA WAS ABOUT HALF NORMAL AND THEN BROKE! WE THEN ACQUIRED AFTERMARKET BOLTS LOCALLY AND HAD NO PROBLEMS TIGHTENING THEM TO MANUFACTURER'S SPECS. IT IS MY THEORY (AND FEAR) THAT MACK'S SUPPLIER HAS PROVIDED BOLTS OF INFERIOR QUALITY FOR YEARS AND THAT THOSE BOLTS HAVE BEEN USED IN THE ASSEMBLY LINES AS WELL AS IN MACK PARTS DEPARTMENTS NATIONWIDE. I AM ASKING THE NHTSA TO INVESTIGATE THIS PROBLEM BECAUSE ABF MANAGEMENT SEEMS UNWILLING TO VIGOROUSLY SEEK A SOLUTION. AFTER THREE YEARS OF BOLT FAILURE OUR LARGEST ABF PARTS DEPARTMENT ONLY STOCKS ENOUGH BOLTS TO FIX ONE TRUCK AT A TIME. I AM ALSO CERTAIN THAT THESE BOLTS ARE IN SERVICE IN MANY OTHER FLEETS ACROSS THE NATION, SO IT IS NOT A PROBLEM THAT ABF SHOULD HAVE TO SOLVE ALONE. I HAVE PHOTOGRAPHS AND SAMPLES OF THE DEFECTIVE HARDWARE AND CAN OBTAIN MODELS AND VIN'S IF NECESSARY. *TR

NHTSA ID

10356665

Incident

Jan 10, 2010

CBR -Telematics Gateway (TGW) Connect Ability Issues

CBR - Active "Set Park Brake" Message On Drivers Information Display (DID).

CBR - Automated Manual Transmission ( AMT ) Flywheel Pilot Bearing Wear On Input Shaft.

TSB: Mack Trucks now offer an improved HD Inter-Axle Through Shaft for the CRD 125, 150, 180, and 200 family carriers. The new HD shaft went into production on January 23rd, 2023 for 2.54 - 3.50 axle ratios and April 1st, 2023 for 3.56 - 3.98 ratios. The new HD through shaft is an upgrade over the current standard shaft and can now be used as a replacement part instead of the standard shaft. The new HD shaft has a new design to increase strength, longevity and life over the standard shaft.

TSB: Air Restriction Indicator

TSB: Barksdale Leveling Valve, Leak Test