https://www.truck-manuals.net/mack/ 110 OPERATION SEAT BELTS DANGER Seat belts should always be secured BEFORE the vehicle is set in motion. Failure to use seat belts can result in SEVERE bodily injury or death. Unbelted riders could be thrown into the windshield or other parts of the cab, or thrown out of the cab entirely.
Seat Belt Operation MACK vehicles manufactured on or after September 1, 1990 must have locking retractable seat belts. For all seating positions in your MACK vehicle, this type of seat belt is a combination lap and shoulder belt. This type of belt is designed to lock (prevent belt travel out of the retractor) only during sudden stops or impacts. This feature allows the operator to move freely under normal conditions. Seat belts cannot be locked by jerking on the belt, except during sudden stops or harsh bumps.
Fastening Seat Belt 1. Pull clip so the belt crosses your shoulder and lap and insert it into the buckle until an audible snap is heard.
DANGER Use the shoulder belt only on the shoulder that is closest to the vehicle door. Never wear the shoulder portion of the belt under your arm or behind your back. Improper use will increase your chances of injury during a collision.
DANGER To prevent possible injury the belt must be positioned low over the pelvis, below the abdomen. If the belt is buckled too high, it will apply force to the abdomen, not the pelvic region, and could cause serious internal injuries during a sudden stop.
