Re: Harmonic Balance Install
End play is easy, attach a dial indicator to the block with the indicator in contact with the crankshaft snout.
Pry the crank forward and backward until you have a end play reading.
Check it against the specs in your rebuild manual.
Balancer is a little harder...
Inspect the hub and ring VERY closely for cracks. If you find one, you need a new balancer.
If the balancer is used, start by looking to see if the rubber is 'domed up' above the metal halves, or if the rubber has visible cracks.
In both cases the balancer is shot. You need a new balancer.
You can also pull (hands only) on the outside ring of the balancer to see if it moves. (sliding on the rubber instead of moving with the rubber).
If it does, you need a new balancer.
Roll your engine over to TDC on #1 compression. You will need to use a wooden dowel rod in the sparkplug hole to find TDC. (chop stick works really well)
(this is a good time to verify your distributor timing, rotor should be pointing at #1)
See if the balancer is pointing to TDC ( Zero '0'). If it is not, you need a new balancer.
(Everyone should do this test at every tune up. It's fast, easy, and finds the problems before they find you...)
You will have to preform this check several times after running the engine to see if the outside ring is 'slipping'...
(slipping, rubber bond broken between outside ring and hub, letting the outside ring move around the hub)
Luckily, it's real easy, find compression stroke on #1, and use your wooden dowel rod to find TDC of the piston.
If the ring comes up anything but '0' (Zero) you need a new balancer.
(Piston to Crankshaft Position never changes, so that's your constant, check everything else against that constant.)
So many cats, so few recipes...