Drivetrain

Removing the clutch is quite simple. The clutch is held in by eight bolts. Remove four, leaving four opposite each other. Undo these evenly bit-by-bit. If you plan on reusing the clutch take your time in this step to prevent damaging the spring. The clutch is quite heavy so take care lifting it out. The most common way I see these clutches fail is the springs break and the housing that holds them flogs out.

Also inspect the other clutch disc. Inspect the flywheel for large deep cracks. You can get a dial gauge and inspect the flywheel for run-out, but any time I replace a clutch I remove the flywheel and get it machined so the new clutch has a nice flat surface. Undo the row of bolts holding the flywheel in place use a lever bar or screwdriver to wiggle the flywheel off the back of the crank. Sometimes it's stuck quite tight and you might want to use a dead blow soft faced hammer to jar it loose. Replace your spigot bearing by hitting the old one out then hitting the new one in.

I've used a flat plate to hit the bearing in which works okay but if you're going to use a socket or a punch make sure that you hit on the outer race not the inner race. Hitting on the inner race will damage your bearing. Once the bearings been fitted give it a spin make sure it's still spinning freely. Lift the flywheel into the flywheel housing then use a screw driver to lever it up on the back of the crank. Fit the bolts, run them up evenly with the rattle gun. It might be hard to tell by the video but I'm not doing them up really tight with the rattle gun. That is done with a torque wrench. Torque the bolts up to manufacturer's specifications. This is a Cummins, it's 200 ft lb. Wipe the surface of the flywheel ready to fit your clutch. These heavy-duty clutches are made up of a pressure plate an intermediate plate and two clutch plates.

It's important these clutch plates face the right direction. The way it needs to face is written on the clutch plate.

So with this in mind fit a dummy shaft into the clutch with the pressure plate then a clutch disc then the intermediate plate then another clutch disc. A dummy shaft is the old input shaft out of the gearbox, you need this to line up the splines and centralize the clutch on the flywheel. If you don't have one go to your local truck dismantlers.

With the dummy shaft in the clutch lift it up so the nose of the dummy shaft goes in the spigot bearing. This will now hold the weight of the clutch and you are able to turn it to line up the bolt holes. Use a screw driver to lever up to assist this process. Start each of the bolts, do the bolts up evenly bit by bit. Once the bolts have been done up the weight will come off these blocks of wood and they should fall out.

Make sure these blocks of wood do actually fall out. I've seen it before when they've been left in and the gearbox is bolted back up and the clutch doesn't work. Tighten the last part with the torque wrench to 50 ftlb. Remove the dummy shaft, if the old clutch had a grease line be sure to change that over. On a final note the intermediate plate has four dowels, these dowels should be pressed up hard against the flywheel when the clutch has been bolted in. If they aren't, stick a punch through the hole in the pressure plate and tap them in