Step Four: Lift the upper section off which will expose the driven plate. There are three short toggles that fall out as seen in the picture to the left. You can now remove the plate, clean everything and put the replacement disc in. If your plate is still good, but oil soaked - wash it quickly with non-chlorinated brake cleaner and dry with compressed air a few times. If in good shape it can probably be used again, but you need to address the oil contamination source (either transmission or rear engine oil seals). We normally just replace the discs since the tractor is split and the cost is not unreasonable (keep the old discs as spares - these tractors are getting old and parts may be difficult to get some day).
Step Two: Identify the three release fingers for the first plate. These fingers have double nuts that lock them in place. The lock nuts are quite thin and it's helpful to take a cheap wrench and grind the face so that it is thin enough to anchor the lower nut.
Step Three: Once you remove the three lock nuts, you unwind the three nuts under tension, evenly. I usually take a half turn on each nut continuously until they wind off by hand. (This prevents damage to the unit).
Step Five: Assemble in reverse order. This may be easier if you flip everything over to assure the three toggles are engaged on their pins properly (you will need to use a small screw driver or punch to align them). Once aligned, add the fingers / bolts and wind the nuts on by hand until engaged. Flip over and ensure the toggles are still aligned. Carefully center the disc and tighten 1/2 turn at a time until the bottom plate aligns with the bottom of the pressure plate (picture at right). You now need to finish with the lock nuts and your clutch pack is ready to reinstall.
We normally measure the width of the new PTO disc and ensure it will release by carefully compressing the disc on the press. Once compressed the width of the new disc should fit or the tension bolts can be fine tuned.
This may be a good time to take your digital camera and begin taking pictures. We find it easy to refer to pictures rather than memory when it comes to reassembly. We are not saying you have a bad memory, we are just admitting we do and offering a suggestion that we have found helpful. Almost every cell phone has a good camera on it and it's well worthwhile to use it to document dissassembly.
Replacing the captive disc on a 2 stage clutch looks worse than it actually is. The Italian 2 stage clutches are truly captive, you have to disassemble the pressure plate to gain access to the inner disc (unlike some conventional clutches, you can't simply compress the clutch and remove the finger pins).
Step One: Place the clutch assembly on a bench or flat surface. Using a punch, mark all pieces of the pressure plate so that it can be reassembled exactly the same. The plates are balanced and need to be assembled the same way.
Clutch plate and release bearing replacement is normally a good idea. They aren't expensive and unless the plate looks like the photo to the right (raised pads still visible on both sides) it would probably make sense to replace it. You could also measure the friction material and compare it to a new plate:
Pasquali 988, 986 - 3.5 mm / all other models are 4 mm
Ferrari models - 3.8 mm
Goldoni - 3.8 mm
Note: Always replace the release bearing regardless.
Note the wear on the tips. In this case, wear like this isn't that bad and the plate could be used again. The next picture shows a broken arm and that's a no-go situation. Either replace or rebuild the plate. We carry parts to rebuild original three arm plates, but the newer diaphragm style is less expensive and easier to set up.
The other consideration is the pressure plate surface. Check carefully for heat stress, which shows up as darkened "burnt" areas, small hairline cracks or discoloration.
If the surface is smooth and there hasn't been metal to metal contact or damage, you could break the glaze on the plate and re-use it.
Although the plate face shown to the left is a bit sketchy, we would re-use it. It has no deep grooves and heat stress is minimal. Take a sheet of 120 grit sand paper, set it on a hard, flat surface and rub the pressure plate face against the sand paper in a circular motion to "break the glaze" and renew the face.
Fortunately, replacing the clutch group on a Euro tractor is easy and not beyond the scope of the backyard mechanic. The beauty of the articulating design is that the tractor sits on all four wheels during clutch renewal. You need to have a roll away jack, engine hoist or over head crane to hold the engine while you roll the tractor back to expose the clutch. Gary Nash, a well known Pasquali dealer in the U.S. used to renew a clutch pack in as little as 2 hours. Nash was legendary during the 1980's when Pasquali tractors were at their peak in the U.S. and is well known among long time Pasquali owners.
Assessing the clutch pack is straight forward. Of the two types of pressure plates, the three arm is the most common to Italian tractors.
Normally, the arms wear from contact with the release bearing. While arm ends differ from plate to plate, the worst wear is at the tip. Often, the end of the arms have "bumps" that ride against the release bearing. If the bumps are worn off, the plate needs rebuilding or should be renewed. With diaphragm plates, the tips wear and fingers can bend or crack. Inspect both plate types for broken springs, fingers, arms or any type of cracks.