RECALLS — MACK GU
Mack GU recalls
Mack GU model years 2010–2023 covered by at least one recall campaign. Pick a year to see the Canadian and U.S. campaigns side by side.
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U.S. NHTSA campaigns are listed on each year page, where they are queried live by model year. The Canadian list below covers every year together.
Transport Canada recalls
23- Lights And Instruments#2023474
5,280 units affected
Issue: On certain trucks, the front turn signals may not be visible from certain angles. As a result, the trucks don't meet the requirements of the Canadian regulations. Safety Risk: Turn signals that aren't visible from certain angles may cause a person not to recognize when a driver intends to turn or change lanes. This could increase the risk of a crash. Corrective Actions: Mack will notify owners by mail and advise you to take your truck to a dealership to install additional front turn signals.
- Structure#2020551
91 units affected
Issue: On certain trucks, the welds that attach the trailer hitch may crack due to improper welding. As a result, the hitch could detach from the truck while towing a trailer. Note: This recall only affects certain trucks with trailer hitches installed by Commercial Truck Equipment. Safety Risk: A trailer that detaches from a truck could create a risk of a crash. Corrective Actions: Commercial Truck Equipment will notify owners by mail and instruct you to take your truck to a dealer to inspect the trailer hitch and repair or replace it, as necessary. You should stop using the trailer hitch until the inspection and repair have been completed.
- Powertrain#2016495
1,690 units affected
On certain vehicles, the cap nut that retains the interaxle driveshaft yoke to the rear axle input shaft may prematurely loosen. If the nut were to loosen and come off, the yoke could separate from the axle input shaft and cause the drive shaft to disconnect. A disconnected drive shaft would result in a loss of motive power, and create a road hazard, both of which could increase the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect the torque on the cap nut, and the nut will be replaced if the torque is found under specification. Note: This is an expansion of recall 2016-079.
- Powertrain#2016079
1,068 units affected
On certain vehicles, the cap nut that retains the interaxle driveshaft yoke to the rear axle input shaft may prematurely loosen. If the nut were to loosen and come off, the yoke could separate from the axle input shaft and cause the drive shaft to disconnect. A disconnected drive shaft would result in a loss of motive power, and create a road hazard, both of which could increase the risk of a crash causing injury and/or damage to property. Correction: Dealers will replace the cap nut, and inspect the threads on the input shaft. If the threads are damaged, the input shaft will be replaced.
- Steering#2016078
130 units affected
On certain vehicles, the roll pin may not have been installed on the upper yoke on the steering shaft during assembly. If the roll pin is missing, the steering shaft may disconnect from the yoke. Separation of the shaft from the yoke would result in complete loss of steering, increasing the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect the steering shaft, and replace it if the roll pin is found missing.
- Brakes#2015373
3 units affected
Certain vehicles fail to comply with the requirements of Canada Motor Vehicle Safety Standard 121 - Air Brake Systems. These vehicles were built with insufficient air tank reserve capacity, which may provide an insufficient air supply to properly operate the brakes during repetitive brake applications. This may result in reduced braking performance which could result in a vehicle crash. Correction: Dealers will install an air tank to increase air reservoir capacity.
- Brakes#2015372
241 units affected
On certain vehicles, The chassis electrical harness and air brake lines may not have been properly secured at the crossmember. This could cause the electrical cables and air lines to fall down and get twisted in the driveline. This could affect safety systems such as brakes, increasing stopping distances or causing unintended parking brake application. This could increase the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect and repair the vehicle as needed.
- Electrical#2015017
32 units affected
On certain model vehicles outfitted with an Automatic Over-Speed Protection system, the system may be incorrectly wired. This presents a potential risk as the operator may not be able to control an unintended increase in the engine RPM if combustible vapors enter through the air intake. If this occurs, it could increase the risk of an engine fire that may cause injury and/or property damage. Correction: Dealers will inspect and repair accordingly.
- Electrical#2014527
11,668 units affected
On certain model vehicles, water around the windshield can migrate into the Electronic Power Distribution Module and contaminate it. As a result, circuits may be bridged creating an electrical short. This could potentially result in a fire, increasing the risk of injury and/or damage to property. Correction: Dealers will inspect the module, and if found contaminated, will replace it. Additional measures will be taken to address the leak if contamination is found. Note: This is an expansion of recall 2014-053.
- Powertrain#2014439
13 units affected
On certain vehicles equipped with Cummins ISL engines, the fuel filter shell and nut plate could separate, causing a fuel leak and also causing the engine to stall. Stalling would result in a loss of motive power, increasing the risk of a crash resulting in injury and/or damage to property. Correction: Cummins-authorized dealers will replace the fuel filter.
- Seats And Restraints#2014390
46 units affected
On certain vehicles, bolts securing the seat belts to the seat frame, cab wall and cab floor may have been insufficiently tightened during vehicle assembly. As a result, bolts could loosen over time and potentially allow the seat belt to detach from its mounting points. If this occurs, the seat belt may fail to restrain the seat occupant in a crash, increasing the risk of injury and/or damage to property. Correction: Dealers will tighten the affected bolts to the specified torque.
- Lights And Instruments#2014146
5,990 units affected
On certain vehicles, the directional/hazard signal flasher may fail. Actuation of the turn signal or hazard lights in this condition would cause them to remain illuminated and not flash as intended. As a result, drivers may not be able to clearly signal their intentions to turn, change lanes or warn others in an emergency situation. Correction: Dealers will replace the turn signal/hazard flasher module.
- Electrical#2014053
2,462 units affected
On certain model vehicles, water around the windshield can migrate into the Electronic Power Distribution Module and contaminate it. As a result, circuits may be bridged creating an electrical short. This could potentially result in a fire, increasing the risk of injury and/or damage to property. Correction: Dealers will inspect the module, and if found contaminated, will replace it. Additional measures will be taken to address the leak if contamination is found.
- Accessories#2013454
12 units affected
On certain model vehicles outfitted with an Automatic Over-Speed Protection system, the system may be incorrectly wired. This presents a potential risk in applications where the Power Take-Off system is engaged, which could result in injury and/or property damage. Correction: Dealers will rewire the system.
- Powertrain#2013346
61 units affected
On certain vehicles, spindle nuts may have been installed incorrectly and could loosen, possibly resulting in the hub, wheel and tire assembly separating from the vehicle. This could increase the risk of a crash causing injury and/or property damage. Also, should a wheel separate from the vehicle, it could pose a danger to nearby motorists or bystanders, which could result in injury and/or property damage. Correction: Dealers will inspect and repair vehicles as required.
- Steering#2013345
113 units affected
On certain vehicles, the tie rod end clamp bolts may not have been torqued to specification. As a result, the tie rod ends could separate from the tie rod, resulting in a loss of steering control, increasing the risk of a crash causing injury and/or damage to property. Correction: Dealers will inspect repair vehicles as required.
- Brakes#2013161
906 units affected
On certain trucks, the cotter pin which retains the brake slack adjuster’s clevis pin may have been omitted during vehicle assembly. As a result, the clevis pin could loosen and fall out, causing a loss of brake function at the affected wheel. This could cause the vehicle to pull to one side under braking, or increase stopping distance, which could result in a crash causing property damage and/or personal injury. Correction: Dealers will verify cotter pin installation on each brake slack adjuster. Replacement cotter pins and/or clevis pins will be installed as needed.
- Wheels#2012346
On certain vehicles, the wheel rims may have been manufactured incorrectly and could fail. A wheel separating from the vehicle could cause a loss of control and a crash. In addition, the errant wheel assembly could strike a vehicle, stationary object, or a bystander. These issues could result in property damage and/or personal injury. Correction: Dealers will inspect and, if necessary, replace the wheel rims. Note: Further evaluation revealed that no Canadian vehicles are involved.
- Visual System#2012194
66 units affected
On certain vehicles, the hardware used to affix the windshield wiper linkage to the wiper motor may have been subject to rust and corrosion before assembly. This contamination may have prevented the bolt/nut from being tightened adequately. As a result, the bolt/nut may loosen to a point where the linkage detaches from the wiper motor, which would cause the wipers to stop functioning. Loss of windshield wiping capability, should it occur during a rainy/snowy day, may compromise the driver's ability to see the road and its users, which could result in a crash causing property damage and/or personal injury. Correction: Dealers will replace the hardware in question.
- Suspension#2011409
19 units affected
On certain trucks, the drive axle tower bracket may not have been welded correctly during the manufacturing process. This could allow the bracket to detach from the axle, which could result in a loss of vehicle control and a crash causing property damage and/or personal injury. Correction: Authorized service facilities will inspect and, if necessary, repair weld the axle assembly.
- Other#2011261
76 units affected
On certain trucks, the clutch pedal assembly may have been manufactured incorrectly and could fail. This could allow the clutch pedal to fall to the floor, prohibiting clutch operation, and causing a reduction in braking efficiency. Increased stopping distances could result in a crash causing property damage and/or personal injury. Correction: Dealers will replace the clutch pedal assembly.
- Powertrain#2011205
584 units affected
On certain trucks, the driveshaft may not have been welded correctly during the manufacturing process. This could allow the driveshaft to fracture along the length of the tube seam weld when torque is applied. The fractured tube can twist or sever, which could result in additional damage to the driveline, the vehicle to which it is attached, and any additional nearby components. Should the brake air lines become damaged, it could allow spring brake application, causing immediate brake lock-up. If this occurs while the vehicle is in motion, it could result in a crash. Also, failure of the driveshaft would result in lost vehicle propulsion which, in conjunction with traffic and road conditions, and the driver's reactions, could increase the risk of a crash. Either condition could result in property damage and/or personal injury. Correction: Dealers will replace the driveshaft assembly.
- Brakes#2011182
329 units affected
On certain vehicles, the slack adjuster housings may have been manufactured incorrectly, which could allow the housings to fracture and fail. As a result, the wheel brake to which the slack adjuster is attached would no longer function, which could increase vehicle stopping distances. Should a steer axle slack adjuster fail, it could also cause the vehicle to pull to one side during braking. Either problem could result in a crash causing property damage and/or personal injury. Correction: Dealers will inspect and, if necessary, replace the slack adjusters.
Canadian data updated August 24, 2026
Does this recall apply to my vehicle?
Matched by make, model, and model year. Many recalls affect only specific VIN ranges — confirm with your dealer using your full VIN.
What to do
Recall repairs are free at a franchised dealer in both countries. To confirm a recall applies to your specific vehicle, contact your manufacturer or dealer with your full VIN, or use the official channel:
- NHTSA recall lookup (search by VIN) — U.S. National Highway Traffic Safety Administration
- Defects and recalls database — Transport Canada