Mack Granite (GR) Problems by year

Background and Contracted Scope At the recommendation of Mountain West Service Manager Kendall Weaver, I contracted with Mountain West to install an engine-mounted PTO (Power Take-Off) hydraulic pump on Truck #37 for use in a side dump trailer application. Kendall represented that the engine-mounted system would be more powerful and better suited to the truck. A side dump trailer requires bidirectional hydraulic flow - controlled pressure in both directions to operate the dump body. The pump specified and...

The contact owns a 2022 MACK GRANITE (GR). The contact stated while a driver was operating the vehicle they stated they felt a vibration in the steering wheel and had issues with a alignment while holding the steering wheel and going down the road the steering was automatically going right, but if they'd let go the steering go towards the left. A vehicle alignment was done. The contact stated she still felt the vibration between 40 and 50 MPH. The vehicle was towed to Vanguard where it was diagnosed to be a drag link failure came apart. The vehicle was repaired. The manufacturer was notified of the failure. The failure mileage was 154,535.

The power divider lockout failed and the thru shaft broke. The driver was pulling onto the high way and heard a loud bang, there was a loss in power. The dealer confirmed the problem and all work was done under warranty. There were no warning lights

The driver was driving down the freeway and lost all power. The driveshaft fell out of the truck at 70 mph, luckly the truck was working a night shift and traffic was light, only a piece was still attached. The dealer confirmed rear differenial failure. There were no warnings before the failure.

The driver was driving down an arterial street and the thru shaft failed on a blind corner. The driver was able to limp the truck to the shoulder. The drivers safety was put at risk as well as everyone else on the road, there would have been no way to move the trailer if it had been loaded and was blocking the road. The dealer was able to replace the thru shaft. The differential failed 7 months later and broke the drive shaft in half. Luckily the driver was able to get over to the shoulder and the pieces wedged between the crossmember and bottom of the truck so nothing was dropped onto the highway. The dealer performed the repairs under warranty. There was no warning before this happened.

The driver was merging on the freeway and experienced complete loss of power. He was able to get over to the shoulder and out of traffic. One of the rear differentials had failed before when the Bull Gear rollers fell out and destroyed the differential carrier but luckily onsite. (Attached is the history of these failures) The truck was towed back to the dealer and was missing the rear drive shaft, which had fallen out on the freeway. This truck has had differential problems and had the differentials replaced multiple times before and since. The dealer performed all the work, before and after this failure. There was no warning before this happened.