Yanmar Clutch Job


One of the most complicated basic maintenance issues you will run into on any compact tractor is a clutch replacement. Just like in your car, clutches in a tractor do not last forever. This job is a 5 star job because of the many steps and some special tools that you will need to buy or rent. It is not a complicated job but it will take some time. If you do not want to tackle this job yourself, and local mechanic can do the job for you.

The job itself is really straight forward. You will split the tractor at the bell-housing. This is the "bell" shaped housing immediately behind the engine. The time consuming part of this job will be removing all of the hoses, wires, and linkages that connect the two sections of the tractor. you will need to remove all hoses, linkages, wires, etc before you start. The tractor will actually need to be in 2 separate pieces when you are done.

You will need a jack under the front and rear end of the split. Determine what end will be the heaviest and put your jack under that end. One end will need to be able to roll away from the other so a "cherry picker" or even a rolling floor jack is a must.

Remove the bolts at the bell housing after the tractor is fully supported. If your jack is at the wrong end, the tractor halves will flop over! BAD NEWS! Be careful.

Once the bolts are out- this is the scary part- the tractor should slide apart fairly easy. You might need to remove the drive shaft on 4wd tractor to allow the tractor to split.

Roll the 2 halves apart. You will see, on the engine side, the pressure plate. It will be the piece with the many "fingers" on the inside. The pressure plate is held on by the bolts surrounding it. Remove these and the plate will fall off. Remove the disc as well (if it did not fall off with the plate). The throw out bearing will be on the transmission side and will slide off of the main shaft with its carrier. The throw out bearing will usually slide off of the carrier with a little persuasion from a hammer or press.

Check the pilot bushing and replace if necessary.

Check the clutch input shaft for damaged or sharp splines. Do not remove it unless you are going to replace it. Replace shaft if splines are wore or damaged.

ALWAYS REPLACE THE THROW OUT BEARING WHEN YOU REPLACE THE CLUTCH DISC!!!! You dont want to have to do this again in a few months!

Re-install the throw out bearing onto the carrier just like it came off. You may need to use a vice or press to get it back on.

Put a small amount of grease on the pilot bushing to make it easier to get together.

You will need to use the tractor's clutch shaft to get the components lined up for reinstallation. The shafts on Yanmar tractors will pull out of the transmission so they can easily be used as a lineup tool. The splines and pilot bushing must be EXACTLY lined up or the halves will not go back together. Slide the disc over the lineup tool and slide the tool into the pilot bushing. Slide the pressure plate over the tool and hold the tool exactly parallel with the frame of the tractor. Tighten down the pressure plate bolts. This will hold the clutch into position. Remove the tool and slide the 2 halves of the tractor together again. It will take a lit of fiddling to get the shaft perfectly lined up in the splines and the pilot bushing. When it is all lined up, it will glide in as smooth as glass. NEVER TRY TO FORCE THE HAVES TOGETHER BY DRAWING THE BELL HOUSING BOLTS IN!!! You may think that it will never go together but it will.