How To - Split The Cases And Replace Crank Bearings (part 1) Video

How To - Split The Cases And Replace Crank Bearings (part 1)

If you need to split the cases or replace crank bearings, but you need some help, you are at the right place. Our step by step video will walk you through how to split the cases and to replace crank bearings and a crank shaft. Watch our industry expert as he splits the cases and replaces crank bearings. Trust Rocky Mountain ATV/MC to have the answers and instructions you are looking for.


Hi, I'm Eric from, and today I'm going to show you how to split the cases and to replace crank bearings and a crank shaft.

We'll need some common hand tools, and also some specialty tools made by Tusk. First of all we have our case splitter tool, our circlip pliers, our crank puller/installer, our clutch hub holder; it also doubles as a flywheel holder. We'll also introduce some other Tusk tools later on.

We're going to start with the top end removed, the antifreeze drained, the oil drained, and we want to do a couple things before we pull the bottom in from the frame. What we're going to do is we're going to pull the flywheel off. To do that we need to remove the ignition cover, remove the clutch cables. Then we're going to use our Tusk clutch hub holder, which also doubles as a flywheel holder, and remove the flywheel bolt.

Then we're going to use our Tusk flywheel puller, and you can see it's a left-handed thread. This tool is really important. It's necessary to get this off. Hold the flywheel. Then we need to go ahead and use our impact screwdriver. It's a K&L. It actually makes it really nice to remove some of these Phillips head screws that are in tight.

On this bike there's a little Allen head that holds the clutch actuator. Go ahead and pull that out. Then we're going to pull our stator off. Set it to the side. Now we went ahead and we've removed it from the frame, and we're going to start on the clutch side.

To start with, we're just going to go ahead and remove the clutch cover, and then remove the outer pressure plate bolts. Do it in a crisscross pattern so there's no warpage. Then pull that out, and you can see there's the spring and the bolt. Go ahead and pull that pressure plate off, and then the clutch plates, both steel, and the fiber plates.

Now we need to go ahead and remove the clutch lifter, it has a thrust washer on it, and also the clutch lifter rod. Notice how it came out because it needs to go back in the same way. Then there is a lock washer on this bolt. Just go ahead and pry it off.

Then we're going to use our Tusk clutch hub holding tool. Make sure you don't tighten your holding tool too tight. You don't want to distort the shape of the clutch hub. Go ahead and pull that off and we're going to need to be careful and make sure what's on the backside. There's normally a washer of some sort.

Next off, the outer basket comes off, and inside that there is a sleeve, a double row bearing, and then a washer. We'll need to make sure that it goes back in the same way it comes out. Next we're going to take off the outer cover, and when we do this we want to make sure that we pull it off careful and try not to upset the kick start gear or spring. Any time you pull off something like that look for washers on the backside.

Now we're going to reinstall the outer clutch basket so that we can remove the primary drive gear. We're going to go ahead and take a soft aluminum washer and actually wedge it in between the gears. The aluminum won't hurt the teeth, but it won't allow it to spin either. Go ahead and pull the outer basket back off. Then pay attention to how this assembly comes off because it will need to go back on the same way. Make sure there's nothing else on there.

Now we're going to take our Tusk snap ring pliers and remove our kick start idler gear. Once again, check for washers. We're going to remove our shift shaft, and then the two bolts that holds our shift pauls on. When you take this out, try to remove it as an assembly. It's hard to get the springs back into the pauls for reassembly.

Next we're going to take the star detent off the end of the shift drum. Go ahead and remove that, and as you're removing it you notice on the backside there's a notch, so when you reinstall it that notch needs to align with the dowel.

Now that we've got that side done we're going to go to the other side, back over to the ignition, counter-shaft side. We're going to remove the case half bolts. Make sure you get them all. There seems to always be a hidden bolt.

In part two we're going to continue splitting our cases using the Tusk case splitter, and then we'll also begin assembly using our crank puller/installer.