Bentolin Harmonic Balancer Installation Tool for Chevy 350 SBC/BBC — Kit with Thrust Bearing & Aluminum Washers

Bentolin's 66515 harmonic balancer installation tool is a heavy-duty installer kit that safely and accurately fits Chevy 350 SBC and BBC crankshafts to press the harmonic balancer into place without damage.

If you work on Small Block Chevy (SBC) or Big Block Chevy (BBC) 350 engines, pressing the harmonic balancer on straight and square prevents crankshaft seal damage and premature wear. This kit replaces part number 66515 and provides a threaded rod, nut, washers and a thrust bearing designed to align and drive the balancer evenly onto the crank snout. Built from heat-treated steel with galvanized hardware and aluminum washers, it’s made to resist corrosion and stand up to repeated shop use.

How does this installer keep the harmonic balancer from getting damaged?

The tool uses a threaded rod and a thrust bearing that lets the installer draw the harmonic balancer onto the crankshaft using steady, controlled pressure rather than hammering. The included aluminum washers create a sacrificial contact surface while the heat-treated rod resists bending under torque.

• Thrust bearing reduces friction and prevents binding.
• Aluminum washers protect the balancer face during installation.
• Galvanized nut gives even pressure and resists corrosion.
• Threaded rod aligns the balancer for straight seating on the crank.

Which engines and crank types is this compatible with?

Designed specifically for Chevy 350 Small Block and Big Block (SBC/BBC) crankshafts, the kit works with common balancer diameters used on these engines. It replaces OEM tool number 66515 and fits the typical crank snout thread sizes found on many 350 Chevy motors.

• Fits SBC and BBC Chevy 350 crankshafts.
• Replaces tool model 66515 for like-for-like use.
• Suitable for aftermarket and stock harmonic balancers with matching bore.

What is included and what materials are used for durability?

The package contains one threaded rod, one nut, one set of aluminum washers and one thrust bearing — the basic components needed to pull a balancer on safely. Components are made from heat-treated heavy-duty steel, with galvanized nuts and aluminum washers to combine strength with corrosion resistance.

• 1x threaded rod — heat-treated steel for straightness and strength.
• 1x nut — galvanized for wear and rust resistance.
• 1x set of aluminum washers — protect mating surfaces.
• 1x thrust bearing — reduces friction and ensures smooth seating.

How do I use the tool step-by-step?

Thread the correct end into the crankshaft, slide the balancer onto the snout, then rotate the nut so the thrust bearing and washers press the balancer on evenly. Turn the nut slowly and check alignment frequently until the balancer is fully seated against the crank flange.

• Thread rod into crankshaft by hand until secure.
• Position balancer squarely on the crank snout.
• Install washers and thrust bearing, then tighten the nut steadily.
• Verify even seating and remove tool once balancer is flush.

Who is this for? This Bentolin 66515 harmonic balancer installation tool is ideal for professional mechanics, home engine builders, and restoration enthusiasts working with Chevy 350 SBC or BBC engines who want a reliable, low-cost way to install harmonic balancers without marring parts or risking seal damage. It’s compact, simple to use, and built to tolerate repeated shop use, making it a practical addition to any engine service toolkit.