The 6.2L diesel engine has 2 flywheels, one to be used for automatic transmissions and one for manual transmissions. The automatic flywheel is made of a heavy steel stamping and the manual flywheel is made of cast iron. See Figure 2-30.
It reduces vibration by smoothing out the power strokes of multi-cylinder engines. Each cylinder delivers power only every fourth stroke. It is absorbing power the other 3 strokes. During the other 3 strokes, the engine tends to slow down. The flywheel resists any effort of the engine to change its speed of rotation because of its inertia. Thus, the flywheel minimizes the effect of the engine trying to slow down or to speed up by absorbing power during the power stroke and then gives it back to the engine during the outer 3 strokes. Thus, the flyweel acts to smooth out the peaks and valleys of power from the engine.
The automatic flywheel (flex plate) should be examined for any signs of cracking. And the ring gear should be checked for worn or broken teeth.
