An operator is using a wheel loader on a construction site. While attempting to dig into a pile of granular material, the loader's engine RPM drops significantly, but the machine does not move forward with the expected force, and the transmission feels like it's slipping. There's no unusual noise from the engine or transmission itself. What is the most likely cause of this issue?

Question: An operator is using a wheel loader on a construction site. While attempting to dig into a pile of granular material, the loader's engine RPM drops significantly, but the machine does not move forward with the expected force, and the transmission feels like it's slipping. There's no unusual noise from the engine or transmission itself. What is the most likely cause of this issue?

Answer options: ✅ A worn or damaged torque converter.

• Low hydraulic fluid level in the steering system.
• A clogged transmission oil filter.
• An over-pressurized hydraulic pump for the bucket.

Correct answer: A worn or damaged torque converter.

Explanation: A slipping transmission combined with a significant engine RPM drop without corresponding movement or typical engine issues points strongly to a failing or damaged torque converter. The torque converter transmits power from the engine to the transmission, and if it's not effectively transferring power, the engine will labour while the wheels don't receive adequate torque. Low hydraulic fluid in the steering system would affect steering, not drive. A clogged transmission filter could cause pressure issues, but slipping is a more direct indicator of a torque converter problem. An over-pressurized hydraulic pump for the bucket would primarily affect bucket functions.