Kuhn HR 3004 / HR 3504 power harrow service schedule

1. Lower the harrow, disengage the PTO, stop the tractor, take the key out and apply the parking brake.
2. Clean each nipple on the roller bearing housings at both ends of the roller.
3. Pump in grease until fresh grease comes out all round the bearing deflector.
4. Turn the roller by hand to check it runs freely, and look at the scrapers while you are there.
5. Wipe off surplus grease.

Tools: Grease gun, Rags

1. Run the harrow for a few minutes so the oil is warm, then lower it to the ground. Disengage the PTO, stop the tractor, take the key out and apply the parking brake.
2. Lengthen the top link to tilt the harrow backwards.
3. Put a tray under the drain plug. Take out the filler plug and its washer, then the drain plug and its washer.
4. Let the oil drain fully and wait until it stops dripping.
5. Clean the drain plug and refit it with its washer (new if needed).
6. Shorten the top link until the harrow sits level.
7. Fill with 6 L of the right oil through the filler hole.
8. Check the level: with the harrow level, the oil should reach the lower edge of the level hole. Refit the plugs and washers.
9. Look for leaks round the central gearbox and the input shaft seal.

Tools: Drain tray (10 L), Spanners for the plugs, Funnel, Rags, Gloves

1. Lower the harrow and any drill on top, stop the tractor and take the key out.
2. Clean and grease each pivot nipple on the rear attachment.
3. Work the linkage through its travel and wipe off surplus grease.

Tools: Grease gun

1. Stop the tractor, take the key out and apply the parking brake.
2. Unlock and slide the guards to reach the universal joints and guide bushes. Slide the black collar back to reach the two nipples on the transmission tube.
3. Clean and grease the universal joints, the two transmission tube nipples and the guide rings.
4. Check the guards are whole and turn freely, then lock them back and hook the guard chains on.

Tools: Grease gun, Rags

1. Disengage the PTO, stop the tractor, take the key out and apply the parking brake. Wait for all parts to stop. If the harrow is raised, support it on stands.
2. Clear any twine, wire or crop wrapped round the blade holders.
3. Measure each blade. Replace it when it has worn to L = 150 mm (see the figure in your handbook) or if it is bent.
4. To change a blade: clean the holder, turn the lynch pin ring with the unlocking key, take out the lynch pin and the connecting piece, and swap the blade.
5. Fit the right blade for the rotor's direction of turn: left-turning and right-turning blades have different part numbers.
6. Check the lynch pin and replace it if worn. Replace all lynch pins every 2 or 3 blade changes.
7. Do one rotor at a time and check each is locked before moving on.

Tools: Kuhn unlocking key, Rule, Gloves, Stands to support the raised harrow

1. Re-read the operator's manual.
2. Check all nuts and bolts are tight. The hitch bolts are 42 daNm (420 Nm).
3. Check all guards and side deflectors are in place and in good order.
4. With the harrow level, take out the gearbox level plug: the oil should reach the lower edge of the hole. Top up with the same oil if needed.
5. Look for oil leaks at the central gearbox and grease leaks from the trough. The trough is filled for life with NLGI 0 grease and is not normally topped up.

Tools: Spanners and sockets, Torque wrench

1. Wash the harrow with a garden hose.
2. Replace worn or damaged blades and roller scraper plates.
3. Touch up damaged paint.
4. Take off the PTO shaft and service it as its own manual says.
5. Store the harrow under cover in a dry place.

Tools: Garden hose, Paint, Grease gun