Truing a wheel by eye gets you close, but dial indicators measure what your eyes can't see. The Park Tool DT-3i.2 replaces the gauge on Park's DT-3 Rotor Truing Gauge, giving you precise readings when straightening bent disc brake rotors. The indicator measures in 0.01mm increments, which matters when you're chasing the tiny wobbles that cause brake rub and pulsing at the lever.

The DT-3i.2 mounts directly to the DT-3 body and reads lateral runout as you rotate the rotor through the gauge. That level of precision reveals problems that visual inspection misses entirely. A rotor might look straight but still have enough deflection to drag against pads set at proper clearance. The dial indicator quantifies exactly how much correction each section needs, so you're not guessing when you apply pressure with a rotor truing tool.

This is a replacement part for gauges that have seen heavy shop use or taken a hit on the workbench. The indicator mechanism is the precision component in the system, and maintaining accuracy means replacing it when readings become inconsistent. If your DT-3 still measures true, you don't need this. If you're getting readings that don't match what you're seeing, or if the needle sticks or jumps, the gauge has drifted out of spec.... Read More