A technician is test driving a heavy-duty articulated dump truck equipped with a powershift transmission. The operator reports that the transmission 'slips' when upshifting from second to third gear under load. Downshifts feel normal. What is the most targeted diagnostic step the technician should take first?

Question: A technician is test driving a heavy-duty articulated dump truck equipped with a powershift transmission. The operator reports that the transmission 'slips' when upshifting from second to third gear under load. Downshifts feel normal. What is the most targeted diagnostic step the technician should take first?

Answer options: ✅ Check hydraulic pressures for the 2nd and 3rd gear clutch packs.

• Inspect the driveshaft universal joints for excessive play.
• Drain and replace all transmission fluid and filters.
• Perform a full recalibration of the transmission control module.

Correct answer: Check hydraulic pressures for the 2nd and 3rd gear clutch packs.

Explanation: Slippage during a specific upshift (2nd to 3rd) strongly indicates an issue with the clutch packs responsible for those gears, likely due to insufficient pressure or internal wear. Checking hydraulic pressures for those specific clutch packs is the most targeted diagnostic step to confirm this. Driveshaft U-joints would cause vibration or clunking, not gear slippage. Draining fluid and filters is maintenance, not a diagnostic. A full TCM recalibration is typically a later step, after mechanical and hydraulic issues have been investigated.