Do not use pliers or pipe wrenches on the adjustment knob. Hand-tight adjustment only.
Proto recommends recalibration at least once a year or more frequently with heavy use. Service and NIST-traceable calibration can be performed at DEWALT Service Centers or specialized Torque Service Centers in Sacramento, Norcross, or Houston. J6342 - Motion Industries proto j6342 user manual
| Problem | Likely Cause | Solution (from manual) | | :--- | :--- | :--- | | Wrench clicks but feels “weak” | Internal spring fatigue or debris | Return for calibration; do not use. | | Locking collar will not turn | Dried lubricant or cross-threading | Clean externally with light machine oil (only on collar threads). If no progress, do not force. Send for service. | | No click when loosening | | The click mechanism functions in clockwise (tightening) direction only. For loosening, use as a standard ratchet – ignore torque marks. | | Adjustment knob is stuck | Locking collar is still engaged | Ensure the spring-loaded knob is pulled OUT before turning. | | Scale markings are hard to read | Dirt or wear | Clean with a damp cloth. If worn, use a paint pen to refresh markings – but do not disassemble. | Do not use pliers or pipe wrenches on the adjustment knob