As a Diesel Motor Mechanic you would maintain, test and repair diesel motors and the mechanical parts of trucks, buses and other heavy vehicles such as transmissions, suspension, steering and brakes.
A Diesel Motor Mechanic will also do any of the following in a normal day:

• Detects and diagnoses faults in engines and parts.
• Dismantles and removes engine assemblies, transmissions, steering mechanisms and other components, and checks parts.
• Repairs and replaces worn and defective parts and reassembles mechanical components, and refers to service manuals as needed.
• Reassembles engines and parts after being repaired.
• Tests and adjusts mechanical parts after being repaired for proper performance, diagnoses and tests parts with the assistance of computers.
• May inspect vehicles and issue roadworthiness certificates or detail work required to achieve roadworthiness