2013 Mack Chu problems

What is wrong

Mack Trucks Inc. (Mack) is recalling certain model year 2010-2014 CHU, CXU, and MRU, 2007 CT and CV, 2008-2014 GU, and 2011-2014 LEU, and TD trucks manufactured February 28, 2006, through November 8, 2013, and equipped Hamsar Electronic Flasher. The hazard warning lights may fail.

Risk

A failure of the hazard warning lights could reduce the trucks visibility, increasing the risk of a crash.

Remedy

Mack will notify owners, and dealers will replace the electronic flasher unit, free of charge. The recall will begin by mid-June 2014. Interim letters went out to owners on June 23, 2014. The recall began on July 25, 2014. Owners may contact Mack customer service at 1‑866‑298‑6586. Mack's number for this recall is SC0379.

Recall number 14V208000 · Recall details

What is wrong

Mack Trucks, Inc. (Mack) notified the agency on February 20, 2014, that they are recalling certain model year 2010-2012 CHU, CXU, GU and TD vehicles manufactured from June 16, 2009, through July 8, 2011. While continuing to research the scope of the issue, Mack expanded the recall on November 18, 2014 to include certain model year 2008-2009 and 2013-2014 CHU, CXU, GU and TD vehicles manufactured from June 16, 2009, through July 8, 2011. Having completed its investigation, Mack once again expanded the recall during February 2015 to include an additional 53,780 vehicles from model years 2007 and 2015. The recall now covers model year 2007-2015 includes CHU, CXU, GU and TD vehicles produced October 13, 2006, through October 3, 2014. In the affected vehicles, the Electronic Power Distribution Module (EPDM) may be contaminated from water leaks in, and around, the windshield. If exposed to water leaks, contaminants such as road salts may deposit on the EPDM.

Risk

Deposits of contaminants may result in the circuits being bridged, creating a high resistance short, increasing the risk of a fire.

Remedy

Mack has notified owners, and dealers will inspect the EPDM. If contamination has occurred, dealers will replace the EPDM and address the leak, free of charge. Owners of model year 2010-2012 CHU, CXU, GU and TD vehicles were initially notified April 24, 2014. Owners affected by the recall expansions were notified in February 2015. Owners may contact Mack Trucks at 1‑336‑393‑2000. Mack's number for this recall is SC0375.

Recall number 14V078000 · Recall details

What is wrong

Mack Trucks is recalling certain model year 2013-2014 CHU, CXU, GU, LEU, and MRU vehicles manufactured with pro-torque axle spindle nuts from August 28, 2012, through August 16, 2013. The pro-torque nut may not have been installed correctly, which may result in a loosening of the nut.

Risk

If the nut comes loose, the hub assembly may separate from the vehicle, increasing the risk of a crash.

Remedy

Mack Trucks will notify owners, and dealers will inspect and repair the vehicles, as necessary, free of charge. The recall began on November 12, 2013. Mack's recall number is SC0371. Owners may contact Mack Trucks at 1‑336‑393‑2000.

Recall number 13V492000 · Recall details

What is wrong

Mack Trucks, Inc. is recalling certain model year 2013-2014 CHU, CXU, GU, MRU, and LEU trucks manufactured July 16, 2012, through march 18, 2013 and equipped with drum brakes. The clevis pin for the brake slack adjuster may be missing a cotter pin. If the cotter pin is not installed, the clevis pin may loosen and fall out causing a loss of brake function on the affected wheel.

Risk

A loss of brake function at one wheel will lead to increased stopping distances and pulling to the left or right when braking, which may increase the risk of a crash.

Remedy

Mack Trucks, Inc. will notify owners, and dealers will inspect the brake slack adjusters and install the brake hardware, as necessary, free of charge. An interim was mailed to owners on June 20, 2013. A second notice was mailed to owners on September 30, 2013. Owners may contact Mack Trucks at 1‑800‑528‑6586. Mack Trucks' recall campaign number is SC0370.

Recall number 13V195000 · Recall details

On April 28, 2020, the Office of Defects Investigation (ODI) opened PE20-005 to investigate reports of 2013-2015 Mack CHU and CXU trucks equipped with mDrive transmissions continuing to push forward when stopping, possibly increasing the risk of a crash. After more field reports were discovered, the scope of the investigation was expanded to cover MY 2013-2016 vehicles. The mDrive transmission is Mack's version of Volvo's I-Shift transmission, an automated manual transmission that allows gear shifting without the use of a clutch pedal. Early I-Shift transmissions were recalled (13V‑268) to address a missing redundant clutch disengagement switch that could prevent the clutch from automatically disengaging when the brake was applied. If a loss of signal from the brake air pressure switch occurred, the clutch would remain engaged while braking.Although Mack's mDrive transmission adopted the latest Volvo I-Shift design and was built with the redundant clutch switch, ODI received field reports alleging that the mDrive transmission would not disengage when coming to a stop like the Volvo I-Shift transmissions in recall 13V‑268.After more than a year of information requests, data exchanges and grouping, and analyzing data, ODI was able to correlate two versions of transmission software (ID 23084009 and ID 23084004), with two frequently replaced parts ('solenoid valve' and 'cylinder assy clutch') as outliers. However, Mack dismissed the replacement parts as being normal service parts for worn clutch systems.According to Mack, unlike the I-Shift recall, loss of one or more of the switches would not keep the clutch engaged but might cause a delay in the clutch disengaging, possibly due to the software/control system settings, the worn parts and system reaction time.To demonstrate the possible switch failure outcomes, Mack outfitted a subject model truck with a panel that could disable each switch on command. During test drives at the Mack facility, the demonstrator truck stopped when the brake was applied each time, and the truck did not stall when the brake was applied, even when the clutch was engaged. Even though failure of one of the switches could delay clutch disengagement, the stopping distance would still be shorter than one of the recalled Volvo I-Shift transmission trucks. With this information, as well as a lack of known crash incidents related to this complaint, ODI concludes that the Mack vehicles do not present an unreasonable risk to motor vehicle safety. Although ODI is closing this PE, Mack/Volvo should continue improving the transmission control unit software to further refine the clutch disengagement strategy. The closing of this investigation does not constitute a finding by the federal safety agency that a safety-related defect does not exist. Claims are still being submitted and the Agency will continue to monitor the issue and reserves the right to take further action if warranted by new circumstances.

PE20005