Review on Dorman 594 220 Serpentine Harmonic Balancer by Jason Hutchinson

OEM looks except the center hub is a second design and the original GM 89017622 Front crankshaft oil seal for my 2003 4 engine Trailblazer 0.2 liters required. The difference between the two Harmonic Balancers is that this one has a seal at the end and a step at the hub. The first design is a straight hub with no end seal. If you have pitch on your original harmonic balancer, you don't need a new gasket. It's fine, just add another spare, but it's probably still good to replace the gasket while you ripped everything off.