Slasher Maintenance - stay safe!
Jan 12, 2023 Posted by Brittany Cunningham
When doing any type of maintenance on this machine, always follow the safety steps described below. Service should only be carried out by qualified personnel. Use only authorised genuine parts for replacement.
The slasher must be adequately supported under its body on all 3 point linkage machines (Make certain it cannot fall). After 1-2 hours work, check all bolts and nuts and tighten if necessary.
Check all fasteners and guards are installed.
Use the pto cover chain to keep the pto off the ground when not connected. This is done by looping the chain over the top headstock bolt and clipping back onto the cover. This is only suitable when the slasher is stationary and is not suitable for transporting on the back of a trailer/ute.
Gearbox
It is recommended the first oil change occur after 50 working hours; subsequent changes should take place after 500-800 working hours. Periodically check the oil level and top up with HD140 gearbox oil if necessary. Regularly check for leaks by lifting the slasher, turning off the engine and looking underneath the slasher for any oil.
Blades
Check slasher bolts and blades every 8 working hours. Check the blades are not jammed, are sharp and evenly worn and are free of nicks and cracks. If too much movement is apparent, replace the bolts and bushes (if fitted). When replacing blades, make sure they are fitted correctly.
Rotor
Remove any foreign material wrapped around the rotor.
Adjustable skids
Check for any damage and make sure they are set to the required cutting height and secured.
Chain stays
Check for damage or stretching in the chain stays and D-shackles and replace if necessary.
Wheel kit
Wheel must run freely on axle and yoke must be lubricated. Note: Bearings are replaceable if necessary.
Power take off (p.t.o.) shaft
Before operating the machine, check that the P.T.O. shaft is securely attached to the tractor and to the slasher.
Confirm the minimum and maximum working lengths of the P.T.O. shaft. The telescopic tubes must be overlapping at least 150mm. If it is necessary to shorten the shaft, talk to Delmade. Check that the tube guards are not damaged and rotate freely on the P.T.O. shaft. Safety chains must be sufficiently loose to allow free turning of the tube guards.
Check that the angle of the joints on the P.T.O. shaft do not exceed 35 degrees. When machine is not in use, protect or cover the P.T.O. shaft from the weather.
Check all components are fully lubricated before use. Frequently grease all points as shown in Figure 2 below.
Slip clutch setting
Slip Clutches need to be set if one of the following occurs:
- The clutch has been repaired (including replacing the friction discs).
- The clutch is slipping in work (clutch getting hot, burning out friction discs, machine slowing down in work). The clutch is not slipping when the machine hits an obstruction (tractor stalls, P.T.O. breaks).
- The clutch has been freed up after a period of storage.
How to set the clutch
The setting of the clutch is dependent on many variables - the work, the size of the tractor, the size of the machine and so on. It is best to set each clutch individually if possible. The aim is to start with a loose clutch and tighten it up to the exact point where it stops slipping in normal work. If set in this way the clutch will slip if any load exceeds this point, protecting both tractor and machine. It is best to set up the clutch with the machine on the tractor which will normally be used, and in conditions which approximate to the normal work the machine does.
These friction clutches are equipped with special Belleville springs, designed to apply pressure that varies with the amount of compression. The compression of the Belleville springs must be adjusted to compensate for wear of the friction linings and to maintain the desired setting.
Do not over-tighten the bolts. This may endanger the function of the clutch. The table below set out spring codes, thicknesses and compression ‘h’ measured as shown in the figure for standard settings. The height of the spring is measured next to each bolt and may be ± 0.2mm of the listed value. The tables also show the amount of rotation of each bolt required to achieve the next higher or lower setting, relative to the nominal setting (listed with no rotation noted on the bolt). In addition to the listed settings, intermediate settings may be obtained by tightening or loosening the bolts proportionately.
The clutch must be quite loose initially to ensure it will slip. Slipping can be identified by the clutch getting very hot. The clutch will always be quite warm in work as the gearbox gets warm. Run the machine for a short distance (20 metres) in work and check the clutch slips. Then tighten each tension bolt up a turn (more if the clutch was very loose) evenly and run a short distance again. Keep repeating this procedure until the clutch is not slipping - it should only take a few stops. As you get to the point at which the clutch is not slipping tighten the tension bolts half a turn instead of a full turn.
If the clutch still slips when you have set the maximum recommended setting, reduce the load. Reduce your ground-speed or take less cut. Otherwise you risk damaging the machine. Whenever a slip clutch slips take all load off it until full operating speed is regained with zero load. Continuing operations with a slipping clutch results in clutch damage.
Continue to work the machine checking the clutch regularly to see how it is performing. You may want to adjust it for varying conditions. If the clutch is too loose it will slip, wearing out the friction discs, getting hot and possibly damaging the clutch pressure surfaces as well. Remember as the plates wear, the tension on them is reduced. If the clutch is too tight it will fail to protect the tractor and machine when an overload occurs.
How to free up the clutch after a period of storage
Slip clutches can seize up if left for long periods without use. To free up the clutch loosen all the tension bolts until the Belleville spring is free of any tension. Then run the machine into normal work so the clutch slips. With the clutch set in this way the machine will fail to work at all, clutch slip being 100%. Run the machine in this way for 30 seconds to one minute. This cleans the surfaces of the clutch. An alternative to this is dismantling the clutch and cleaning it.
This maintenance is targeted towards the Heavy Duty Slasher, guidelines may vary from slasher to slasher so be sure to give us a call or check your user manual.
For more information on the Delmade Slasher Range call 1800 335 623 or visit Slasher Range.
