My mower is vibrating very bad and parts on my mower are breaking for no apparent reason.

Both of these problems are caused by a bent crankshaft. When the crankshaft is bent, the engine is thrown out of balance and will vibrate violently. If the problem is not repaired ASAP, the high frequency vibration will cause all of the metal and hard plastic parts of the mower to fatigue and crack (much like bending a paper clip back and forth until it breaks). It may also rip the oil seals out of the engine and cause the engine to lose most or all of the oil.

Although a bent crankshaft is a serious problem, it can be repaired in most cases as long as the problem is caught early. If you suspect that you have a bent crankshaft, bring your mower in as soon as possible so it can be checked. If you continue to use the mower with a bent crankshaft and parts begin to break due to fatigue, it will no longer be cost effective to repair the mower.