[Farmall] Farmall 504 diesel engine

[Kevin Bish]

When taking the crankshaft out of a 504 diesel. What is the unit that is 
bolted to the bottom of the block in the center of the crankshaft for. It is 
driven by a gear in the center of the crankshaft, and has 2 other gears 
inside the housing that look like they are some kind of counter balancer. I 
don't have a repair manual for this engine, as was just curious what this 
setup is for.Thanks for any information. Kevin.