(ET) Mower deck vibration

["agodfrey" <algodfrey home com>]

Many thanks for all the suggestions and proposed remedies that I received
concerning  this problem.   I also checked it with Bill Gunn.
For the benefit of the  ET list members  with deck vibration concerns, I
will summarize  my findings.

1. According to Bill Gunn, out of balance blades and bent motor shafts
    are the cause of most problems, particularly in decks powered with
the small motors ,(which are about 3 -3/8 in. diam and more easily
identified by the top caps which are secured by screws rather than nuts
which are used on the larger 4 in. dia motors.)

2. If vibration persists on the small motor decks, it is according to  
Bill,
almost certainly caused by motor bearings. He also suggests that replacing
the bearings is a lot less expensive than new motors.

3. On the decks equipped with the large motors, he says this harmonic beat
vibration can generally be damped by installing a flange on the center 
motor
shaft.  (the additional mass alters the resonance).

4. Motor bearings are key to this condition. Mine seem good when run
separately but Bill suggests this can be misleading  due to the dynamic
conditions.

So,   I am convinced again that Bill Gunn and Technical Services are
a valuable and beneficial asset to be supported by those of us who are
intent on nursing these 30 year old beauties.

Al Godfrey