Mack preliminary evaluation PE10042
Failing 5th wheel attachment bolts. NHTSA’s Office of Defects Investigation opened this preliminary evaluation about the fifth wheel assembly on 6 model years (2009–2010). Opened Nov 4, 2010, closed Apr 27, 2011 after 6 months. It led to safety recall 11V209000. became a recall
What NHTSA says
Source: Office of Defects Investigation, as filedOn 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.
A Preliminary Evaluation is the first formal stage: NHTSA has decided the complaints and other information it screened are worth a closer look, and asks the manufacturer for its own data on the condition. The summary is the agency’s own text from its investigation file, unedited; the opening and closing resumes with the full reasoning are on NHTSA’s site under this number.
What this means for an owner
Source: and what happens nextAn investigation is not a finding that a defect exists, and it puts no duty on anyone. NHTSA opens a Preliminary Evaluation when complaints and other reports suggest a condition worth asking the manufacturer about; it upgrades to an Engineering Analysis when the answers warrant testing; it closes either when it recommends a recall, when the manufacturer recalls on its own, or when no defect trend is found. The agency’s own goals are about four months for a petition, eight for a Preliminary Evaluation or a Recall Query and eighteen for an Engineering Analysis; many run longer.
This one became a recall. The campaign page carries the manufacturer’s filed defect, risk and remedy, the build window and every model year covered; whether one specific vehicle is included is settled by VIN at nhtsa.gov/recalls.
Model years it names
Source: as NHTSA filed themAlso named: 2009 Mack CXU; 2010 Mack CXU; 2010 Mack CXU612; 2010 Mack CXU613; 2010 Mack CXU613E; 2010 Mack CXU614.
A vehicle page’s investigation list carries the same action; a name here is the scope NHTSA opened, not a list of affected VINs.
Common questions
Source: NHTSA Office of Defects InvestigationIs PE10042 a recall?
No — it is the investigation that led to one. Recall 11V209000 is the campaign; its page carries the remedy.
Is PE10042 still open?
No. It closed on Apr 27, 2011 and led to recall 11V209000.
Which vehicles does PE10042 cover?
NHTSA opened it on 6 model years: 2009 Mack CXU, 2010 Mack CXU, 2010 Mack CXU612, 2010 Mack CXU613, 2010 Mack CXU613E, 2010 Mack CXU614. That is the scope of the inquiry, not a list of affected vehicles; a recall, if one follows, defines its own population by VIN.