Alamo 02968915C General Information on Flail Mower Vibration

MAINTENANCE

MACHETE BOOM 3/09 Maintenance Section 4-21

MAINTENANCE

General Information on Flail Mower Vibration

EXCESSIVE VIBRATION

Vibration is a MONSTER and if allowed to continu e unchecked, can cause the complete break-u p of a machine

in a very short time.

A properly operated Flail Mower will produce very little vibration. If vibration does occur, the mower should be

stopped and the trouble corrected, as warranty does not cover failures resulting from continued operation after

something happens to cause the mower to vibrate excessively.

Vibration is caused by a rotating part which is out of balance. This could be the cutter shaft or, on those

models having a universal slip joint assembly drive shaft, from th e dr ive shaft.

If the two extrem e end s of the drive sh aft, (the yoke s plines which fit on the tractor power take off shaft and on

the mower gear box driven shaft), are not parallel, vibration will be evident.

This is because of the mechanics of a universal drive wherein the rotational speed thru a universal joint is not

uniform. If the ends of a universal drive shaft are parallel, the uneven rotation effect is cancelled out and the

machine being driven will be driven at a uniform rate of speed. However, if the ends are not parallel, the

uneven rotation effect may be multiplied, resulting in a speeding up and slowing down of the entire mower

system (gear box, extension shaft, pulleys, belt, and cutter shaft) each revolution. This effect can be readily

noticed if the mower, while running, is raised to an extreme height on the tractor lift.

For smoothest operation, the tilt of the mower shou ld be adjusted (on a 3-p oint hitch, by adju sting th e length of

the top link between the tracto r an d the mower ) so that the ends of the d rive shaft are parallel when the mower

is down in operating position. Raising the mower, while running, to extreme heights on the lift should be

avoided.

To check wher e the vibration is originat ing, first be sure the ends of the universal drive shaft are parallel. Then,

if vibration is still present, remove the drive belt and run the mower. If vibration is still present, it most likely is

coming from and caused by a bent drive shaft. If so, the shaft should be replaced or straightened. If the

vibration is gone - the drive portion of the mower is running smoothly - then the vibration is probably coming

from the cutter shaft (it could be a pulley out of balance or a faulty belt with a varying cross section, but this is

not likely).