How to Pin a Crankshaft

LS Based engines are equipped with a pressed on harmonic balancer that is held on with a torque to yield bolt. There is no keyway or timing mark alignment.  The factory bolt is designed to be used one time as it stretches on installation.  When adding a supercharger it will be necessary to “Pin” the crankshaft to the balancer to prevent it from slipping.

The first step is to remove the balancer bolt.  Next install the drilling fixture to the crank. The large bolt will go through the center of the fixture and bolt on tight. This particular fixture has 2 holes for double pinning. Since there is not a lot of room between the crank and cooling system fans, a 90º drill is recommended.  The supplied drill bit is stepped so it will only go in the amount needed to install the pin.

After the hole is drilled use the supplied reamer to clean out the hole and remove and burs and shaving.  Next install the pin. A hammer and punch makes it easy.

Last step is to install a new Crank Bolt. The LSX Dr. recommends installing ARP 234-2503. This bolt is reusable and much stronger than the factory bolt. This will require the use of a 27mm, 12-point socket.  This completes the crank pinning process and will ensure there is no slippage.