Fiero L4-151 2.5L (1985)
Balance Shaft: Description and Operation
Typical Balance Shaft Components
The crankshaft has been modified with the addition of a drive gear machined in the area next to the crankshaft timing disc, Fig. 16. This gear drives the
combination in-sump oil pump and balance shafts.
The balancer assembly consists of two eccentrically weighted shafts and gears which are counter rotated at twice the crankshaft speed by a concentric
gear. These weights on the balance shafts reduce vibration at all engine speeds.