If the problem was not there before the repair then I would be looking at the repair itself. Could the pistons be installed backwards? Was it the correct crankshaft without a doubt? Did you match the casting numbers? Balancers only give a problem if the rubber between the 2 pieces comes out.
The crankshaft pulley unbolts from the harmonic balancer. The harmonic balancer can be removed from the crankshaft with a 3 bolt puller.
The harmonic balancer is located on the front of the crankshaft
On any motor, the harmonic balancer is on the front of the crankshaft. It is what the pulley is bolted to.
The harmonic balancer is attached to the crankshaft using a Woodruff key or a square key and center bolt.
Harmonic balancers are located on the crankshaft, usually the belt side of the engine.
it is behind the harmonic balancer.
behind the harmonic balancer
Crankshaft Pulley !
behind the harmonic balancer on the left side
The crankshaft damper is behind the crankshaft pulley.
A pulley on the end of the crankshaft, where you find the harmonic balancer on your vehicle.
Behind the harmonic balancer.