In the previous article, we were preparing to split the cases and get into the guts of the engine. Once the cases are split, there are many little thrust washers and snap rings that can go un-noticed, so use caution as you disassemble the engine.

While pulling the cases apart, we found it easier to do it from the stator side. Once you have the cases off, look inside the case that the transmission rides on. Be sure there aren't any thrust washers stuck on the bearing. This is also a good time to check the thrust washers and gear shafts for wear. If there is any scoring on either shaft, you should replace them. The thrust washers have a certain amount of wear before they need to be replaced. The thrust washers determine the amount of side to side play on the gear shafts.

It would be wise to take a digital picture of the sub assemblies to have a point of reference.

At this point, take out the dowel pin that holds the shift forks on the output shaft. Do not scratch the pin.

Carefully remove the output shaft while holding the input shaft in place, so it doesn't fall out and mix up the gears.

Once you have the output shaft, try to replace the gears in the same order you remove them. Observe which way the gears are on the shaft, and the location of the thrust washers. If they are not replaced the same way they came off, the transmission will not work. You will need a set of snap ring pliers to remove two of the gears.

Once the gears are installed on the shaft, just reverse the process from when you took it apart. You should be able to spin the gears and test them before you put the cases back together. It helps if you have an extra set of hands to do this, to make sure the gears are shifting properly before you put it back together. You don't want have to take it apart again, if you don't have to.

At this point, you should be ready to put the case halves together. Your favorite gasket sealer should be used to seal the cases together, to prevent any oil leaks. Tap the cases together with a rubber mallet so they are snug. Notice, I said “tap”, not bang!

Stand the motor up right and spin the crankshaft to make sure everything is spinning freely, with no binding. Once again, shift the transmission to make sure it is shifting properly through all the gears-up shifting and downshifting. If it is not shifting properly, you will need to pull it apart again to correct the problem. The most common mistakes are missing thrust washers, or gears that are on backwards.

Once you are satisfied, you can put the rest of the motor back together. If you take your time, and pay attention, you can do this without too much trouble. As stated before, I suggest you have the service manual for reference. It has all of the torque specifications, and the service limits for the shift shafts and gear shafts, as well as the thrust washers. This article is giving you a basic run down and is no way meant to replace the service manual as a point of reference. We hope this helps give you a better idea of what it takes to replace or work on the transmission.

We tested Team Guilty`s 330r with the new gears installed, and it shifted perfectly. What a big difference the 330 is from the stock 250r we were using. I raced it at the District 37 AMA National Hare and Hound in Lucerne Valley in February. The transmission worked great, however, we had some other issues unrelated to the transmission. We should have it ready for the District 38 National Hare and Hound in March.

A big "thank you" goes out to Dean Waters and Off-Road.com for helping with this project, and also to Eric Pealstrom from AC Racing, for all his hard work and help in writing this article.

Available at: