12(12)
7.2.
Rotary hoe blades
The condition of the blades should be checked after every few uses. When the blades are in good shape,
they penetrate to the ground surface better and therefore the hoe needs less power to operate. If the
performance of the rotary hoe has weakened from the original, the blades have probably become very blunt
or some of the blades have been damaged. The blades wear down during normal use and they may bend of
crack as they hit rocks. If the blades are bent, they have deep notches, cracks or similar signs of damage,
the blades should be replaced with new ones.
The blade shaft is consists of pairs of left- and right-
hand blades, and they can be replaced independently
as needed. Highlighted in the adjacent figure are
blades A31979, total of 8 blades fitted on the shaft.
Evenly worn blades can be sharpened. Do not
sharpen the blades razor-sharp, since this will make
them wear down very quickly and over sharpness
does not improve the performance of the hoe. Note
that the blade temperature should remain as even as
possible during sharpening. Excess heating will
weaken the tensile strength and wear resistance of
the steel. Only use blades similar to the original ones.
Abnormal vibration that remains after thorough cleaning of the equipment may be a sign of imbalance of the
blade axle. Replace damaged blades as needed. Imbalance may lead to damage to the bearings. Contact
service, if the vibration persists.
If the blades have large notches or cracks or have worn down excessively, they must
be replaced. Always use good protective gloves when handling the blades.
7.3.
Checking and adjusting the drive chain
1. Lower the hoe on the ground and keep it attached to the
loader. Shut down the engine and disconnect the hydraulic
couplings. Make sure that the hoe is secured against any
movement and is not lowered on its blades, as rotating the
blades creates a risk of pinching between the components.
2. Open the protective housing of the chain on the left chain of
the hoe by removing the two retaining screws. Clean the
housing and the surroundings of the chain. Also lubricate the
bearing of the lower sprocket.
3. Test the tension of the chain by moving it manually in
between the sprockets, as shown in the adjacent figure. If
the chain moves about one centimetre or less, the chain
does not need tensioning, and in this case you may reattach
the protective housing. Lubricate the chain with suitable oil.