Claas Disco 4000 / 3600 / 3200 / 2800 Contour rear disc mowers service schedule

1. Switch off the tractor, take the key out and wait until every part has stopped.
2. Look at the main gearbox and angle drive around the bearing seals, filler and check screws, drain plugs and breathers. Areas wet with oil and dust mean a leak. Have a leaking gearbox repaired by a workshop.
3. Wearing gloves, check each knife for wear, cracks and bending (see the knife task) and check the knife holders.

Tools: Gloves, Rags, Torch

1. Switch off the tractor, wait for everything to stop and wear gloves.
2. Measure each knife 10 mm in from the edge: it must still be at least 36 mm wide. The drilled hole may be widened from 18 mm to 20 mm at most. Check for cracks and bending and never straighten or weld a knife.
3. Take the spare knife box out of its bracket (unhook the spring). It has one place for anti-clockwise knives and one for clockwise knives.
4. Put the fixing lever between the knife holder and the disc, turn the disc until the holder is exactly over the dip in the skid, push the lever down and remove the knife. Clean the area.
5. Fit the new knife with its sharp edge down, the arrow on the knife matching the disc's direction of turn. The holding pin must touch and lie straight in the disc hole.
6. Make sure the knife swings freely and moves easily both ways. Take the fixing lever off.

Tools: Fixing lever (supplied), Gloves, Vernier calliper

1. Replace a knife holder if its contour is worn down from 15 mm to 12 mm, its thickness has worn from 3 mm to 4 mm, the welds on the holding pin are cracked or heavily worn, it is bent, or the pin is no longer straight or is worn to 13 mm.
2. Replace a cutting disc if its knife holes are widened, worn or damaged anywhere.
3. Fit discs with the long axis at right angles to the neighbouring disc. Coat the bolts with Loctite 243 and tighten the disc bolts and cover screws to 85 Nm.
4. Adapters and cutterbar skids: clean the faces, fit the new parts and tighten bolts and nuts to 85 Nm with Loctite on the nuts.
5. Check the anti-wrap guard sits evenly 8–10 mm clear of the feed cylinder.

Tools: Vernier calliper, Spanners, Torque wrench

1. Clear the drain holes in the feed drums so water can run out.
2. Check the bolt-on wear bars and replace them in pairs when badly worn.
3. Replace a missing or damaged cover plate straight away.
4. Replace a damaged sealing washer and refit the discharge plate offset by 90°.

Tools: Spanners, Screwdriver

1. Switch off and secure the tractor and clean the nipples.
2. Grease the points in each hour group when due: 8, 20, 100, 250 and 500 hours. The lubrication plan in your handbook shows the points in each group.
3. At 20 hours, grease the first nipple on the universal drive shaft, turn the shaft 180° and grease the second.
4. At 100 hours separate the drive shaft for greasing. Remove the plug, turn the cutting discs until the nipple shows in the hole, grease it and refit the plug.
5. At 250 hours pull the black rubber collar back to grease the drive shaft.

Tools: Hand grease gun, Rags

1. Park on level ground with the mower in working position and the mower head horizontal. Switch off and secure the tractor.
2. Undo the bolts on the cover and take the cover off the main gearbox.
3. Unscrew the dipstick, put a container under the drain plug and take the plug out. Drain all the oil.
4. Clean the drain plug and refit it tight.
5. Top up through the filler opening until the oil is between the A (maximum) and B (minimum) marks on the dipstick. Rest the dipstick in place without screwing it down to read it.
6. Screw the dipstick in tight and refit the cover.

Tools: Drain tray (at least 2 L), Spanner, Funnel, Rags

1. Park on level ground with the mower in working position and the mower head horizontal. Switch off and secure the tractor.
2. Unscrew the dipstick with breather from the angle drive and put a container under the drain plug.
3. Take the drain plug out and drain all the oil. Clean the plug and refit it tight.
4. Fill through the filler opening until the oil is between the A and B marks, then screw the dipstick back in tight.

Tools: Drain tray (at least 1 L), Spanner, Funnel

1. Run the mower head for about 20 minutes so the oil is warm, then stop the PTO.
2. Swing the mower head up to vertical, switch off and secure the tractor and support the raised machine. Wait 10 minutes for the oil to run down.
3. Take the screw plug out of the filler opening. The oil should be up to the bottom edge of the opening and not milky.
4. To change: unscrew the skid, put a container under the drain plug and take the plug out. Drain all the oil.
5. Coat the drain plug with Loctite 2701 and tighten it to 40 Nm.
6. Fill through the filler opening up to its bottom edge and tighten the screw plug to 40 Nm.
7. Check the mower head for leaks round the drain plug and the shafts. Replace any leaking seals.

Tools: Drain tray (at least 5 L), Spanner, Torque wrench, Funnel

1. Tighten the clutch nuts evenly to take the load off the friction plates.
2. Turn the clutch hub by hand to free any stuck plates.
3. Turn the nuts back to the end of the thread so the clutch is ready to work.
4. Look through the opening in the clutch housing at the lining. If no lining is visible, the friction disc needs replacing at a workshop.
5. Do not change the maximum torque (1,350 Nm). Shaft friction clutches should be cleaned by a workshop after harvest and after pressure washing.

Tools: Spanner

1. Lift the mounting frame to full height, lower the mower to the ground, set float and bring the load-relief pressure to 0 bar before working on the hydraulics.
2. Look at every hose for damage and leaks. Read the date on the hose fitting: year (for example 20) and month (07).
3. Replace any hose over 6 years old at a workshop.
4. Every 5 years have the accumulator preload checked at a workshop: Disco 3200 should be 50 bar (4000 60 bar, 3600 65 bar, 2800 40 bar). Top up with nitrogen only.

Tools: Pressure gauge on the machine, Rags

1. Replace worn, loose or missing bolts, pins and split pins. Retighten anything loose.
2. Check the shock absorber nuts (Disco 4000 / 3600 / 3200) and tighten to 25 Nm.
3. Check the movable safety guard holders and that the conical washers are fitted the right way round. Disco 3600 / 3200 / 2800: front holder nuts 12 Nm, rear holder 25 Nm (Disco 4000: 8, 25 and 20 Nm front, rear and side).

Tools: Torque wrench, Spanners

1. Remove crop residues and dirt from the machine.
2. Before pressure washing, grease the bearings, then run the machine briefly to push water out and grease again so a grease collar shows.
3. Clean the hydraulic cylinder rods and coat them with grease.
4. Grease every grease point until grease escapes and run the machine briefly.
5. Top up the gearbox oils to the right level.
6. Check for wear and damage and arrange repairs. Touch up rust and paint damage.
7. Park in a dry building away from fertiliser and reduce the hydraulic pressure.

Tools: Pressure washer (not at the bearings, clutches, decals or electrics), Grease gun