How To - Split The Cases And Replace Crank Bearings (part 2) Video

How To - Split The Cases And Replace Crank Bearings (part 2)


This is part two of the split cases crank and crank bearing replacement video. Please refer to part one for the previous disassembly.

Using the Tusk case splitter, we're going to go ahead and put this on the ignition side. There's a couple important things to remember with this tool. First of all, it needs to be level with the case, so the tool pulls it level. It also needs to be centered on the crank. The bolts don't need to be tight. You don't want to damage the sealing surface, because the pressure will not be on the case half. It will actually be on the bolts. You go ahead and use a ratchet and start to press that splitter in. You can see that it's starting to split the case. You want to make sure that the case is coming apart parallel. If it doesn't, sometimes you need to take a rubber mallet and tap the back side so that it comes out together. You don't want it coming off at an angle. It needs to all come out parallel.

Once you're done with it, go ahead and remove the puller, and pull your case house half off. As you do this, you want to make sure that there's no washers that have stuck to the inner races of the bearings on the other side, so you don't misplace them. Now you can see everything exposed. There's your transmission, your crank. We're going to go ahead and pull the transmission out. That's your counter shaft, your main shaft. Make sure and try to keep them all together, all your shift forks, then lay them out. Make sure and check for washers in your shift drum also. Now is a good time to check for wear on your cogs.

Now, we're going to go ahead and push the crank out from the other side, using our splitter again. What we've done is we've mounted this to the clutch side. We're just pushing that crank out. As you can see, it comes out nice and straight. Make sure, once again, that your puller is centered on the crank.

We're going to inspect our rod at this time. Now, side to side movement is OK, but it's just the straight up and straight down movement is what you want to check for. If it is loose, ProX or Hot Rods makes a complete crankshaft assembly, or you could have your crank rebuilt by a machine shop.

Now it's time to remove the crank bearings and seal to start off with. We'll remove the seal retainers. We'll flip it over and use a punch or a screwdriver, and pound that seal out. We also want to remove the centering dowels so we can lay the case flat on our clean work area. We don't want to mess up the sealing surface of that case half. Use a large socket and pound out the main bearing. It may take some considerable force. You're going to go ahead and clean it up at this point.

You want to make sure and get some new quality bearings to install. What we need to do is we need to use what's called 'sweating it in'. You heat up the case half, and then you're going to freeze the bearing. We want to heat this up. We're just using a propane torch. We want to heat it up until water just barely sizzles. It's about 200 degrees. We've had our bearing in a little cooler with some dry ice, to shrink that bearing up. We want to use some gloves. Protect your hands. This bearing is very cold at this point. We want to wipe off the ice, so this slides right down in there. There's some condensation forming and some ice. You actually just drop it right in. If you've done it right, it should just slide right in.

Now, we're installing our seal, our crank seal. It might be a good idea to do this later, after you've installed the crankshaft. Here is the seal retaining clips. Use some medium strength thread locker on them. You don't want any of these bolts coming loose inside your case. Lubing up the outside of the seal for the other side. This also, you can install this seal after your crankshaft has been installed. Here's all your parts laid out on your clean work area. They're in order. They're organized. We know how they're going to go back in.

Alright. We're going to start to install the crank. We've got our new bearings. We're going to go ahead and reset the inner surfaces a little bit. We're going to go ahead and set the crank in the bearing and flip the case half over, and install the crank installer. There's several parts, adapters that adapts it to the end of your crank.

There is an aligning notch that this tool goes down onto. Nut on the outside. Thread that on a little bit. Some cases, you can actually just rest the puller down on the case, just outside the bearing. On this model, we needed to use some bar stock to hold it up and away from the bosses that were interfering. The bar stuck just holds it parallel to the case, where there's no interference. We're going to go ahead and start tightening the nut, which will pull the crank in. You want to make sure that the rod is up or where it needs to be, so it doesn't interfere. You're going to go ahead and tighten that. It pulls the crank all the way in to where it needs to be.

This concludes part two. Please refer to Split Cases Crank and Crank Bearing Replacement, part three, for additional assembly instructions.