dewalt 20v max drill making a weird clicking noise when i pull the trigger in reverse

Diagnosis

The clicking sound you are hearing when initiating reverse rotation on the DeWalt DCD771C2 is typically the result of the mechanical brake and the forward/reverse selector slider engaging the planetary gear set. In this specific 20V Max model, the trigger assembly is linked to a braking mechanism designed to stop the chuck instantly when the trigger is released. When you shift the direction slider to the reverse position, you are physically moving the gear engagement pawls. The "single click" occurs because the internal components need to seat themselves into the new rotational direction before the motor applies full torque. This is a normal mechanical characteristic of the DCD771C2's drivetrain. You can confirm this is normal behavior if the click happens only once upon the initial pull of the trigger after switching directions, and if the drill maintains consistent RPMs and torque without slipping or grinding once it is up to speed. If the click is a sharp, singular snap, it is the brake releasing; if it is a rhythmic clicking during operation, you have a different mechanical failure.

How to Fix It

Since this is a design feature of the DCD771C2, there is no "repair" needed for a single startup click. However, to ensure the mechanism is operating at peak efficiency and to minimize unnecessary wear on the selector switch, follow these operational steps:

1. Ensure the trigger is completely released and the motor has come to a full stop before sliding the forward/reverse switch. Moving the switch while the motor is spinning can cause excessive wear on the internal pawls.
2. Firmly push the direction selector all the way to the reverse position. If the switch is left in a "half-way" state, the tool will not engage and you may hear a hollow clicking sound without any rotation.
3. Apply a gradual squeeze to the trigger rather than a sudden "slam." This allows the mechanical brake to disengage smoothly from the armature.
4. Check the battery seating. Ensure the 20V Max battery is clicked fully into the rails; a loose connection can sometimes cause a momentary electrical arc that sounds like a mechanical click.

If That Didn't Work

If the clicking is continuous, sounds like metal-on-metal grinding, or is accompanied by a loss of power, try these advanced troubleshooting steps:

• Inspect for Debris in the Selector Switch: Fine drywall dust or sawdust often packs into the crevices of the forward/reverse slider. Use a can of compressed air to blow out the switch gap. If the switch cannot travel its full distance, the gears won't seat properly, causing a repetitive clicking sound as the motor slips.
• Check the Clutch Collar: Rotate the torque adjustment ring (the numbered collar) to a different setting. If the collar is stuck between settings, the internal clutch may be partially engaged, creating a clicking noise that mimics a reverse-gear issue. Rotate it fully to the "drill" icon to see if the noise disappears.
• Lubricate the External Switch: Apply a tiny amount of dry PTFE lubricant to the exterior of the direction slider. This ensures the switch snaps fully into the reverse position without sticking, which prevents the "half-engagement" click.
• Test with a Different Battery: Swap your current battery for another 20V Max pack. A cell with high internal resistance can cause the motor to "stutter" during the initial voltage spike of a direction change, which can sound like a mechanical click.

Heads Up

• Avoid "rocking" the drill back and forth rapidly between forward and reverse under heavy load, as this puts extreme stress on the planetary gears and can eventually turn a normal click into a permanent gear strip.
• Keep the vents clear of debris; overheating in the DCD771C2 can warp the plastic housing around the trigger assembly, leading to misalignment of the reverse switch.
• If you notice metal shavings in the battery terminal area or coming out of the gear housing, stop use immediately as this indicates a failed bearing or gear tooth.
• Periodically wipe down the chuck and the selector switch with a damp cloth to prevent abrasive grit from entering the internal trigger mechanism.