The CTA Manufacturing Flywheel Holder for 6.6L Duramax, No. 5455, locks flywheel in place when removing harmonic balancer. For use on 6.6L Duramax engines with Allison automatic transmission. Instead of having to remove the starter, technicians can save time by locking the flywheel at the transmission for water pump replacement, the company says. The tool includes a 36mm 12-point socket with 3/4" square drive that is used to remove the harmonic balancer bolt and to re-torque during installation. Applications include Chevrolet Silverado 2500, 3500, 4500, and 5500.