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I couldn't find a step-by-step guide on how to install the transmission, shift forks, and shift drum, so I thought I'd make one myself. I asked for tips on how to do the install in a thread I started a few weeks ago, but besides Terse no one replied, so it seems I'm not the only one who needs some guidance on how to do this. Now yes, it is possible to assemble all the components together loosely, and then slip everything into position in the cases in one shot. But you'd better be a God-level mechanic and be sticking your tongue out just right while using exactly the right combination of swear words to actually pull it off. So I present to you here the easy, albeit long way to install the transmission.

The key to doing it this way is to separate the shift forks from the shafts they're attached to. There is a small pin that is pressed through the fork and shaft that locks them together. You only need to separate two of the three forks, and it's easily done with a hammer and a punch. If you don't separate the shafts from the forks, you will have a hell of a time trying to get everything lined up and installed properly. Yes, it can be done. But after an hour of fighting with it, I decided to try this method.

Install everything into the right case half propped up on some 2x4’s so the transmission shafts can stick through. Here's what it should look like starting out

First, lay down first gear of the output shaft. There is no washer or anything underneath it.

Take shift fork R (this is the fork that you do NOT need to separate from its shaft) and place it into fifth gear output. Then place the fork pin into the shift drum as shown below. It will ride in the bottom of the three slots.

This next step will require a little coordination and tongue-sticking-out, but it's still very manageable. Pick those three components up together (the shift drum, the shift fork, and the gear) and drop them into their bearing (for the shift drum) or their shaft (the shift fork) while keeping them all together. This has to be done while holding these components together as they will end up. You cannot put one in first, and then the other. The geometry doesn't allow it.

Next slide the entire input shaft into its bearing.

Now take the remaining portion of the output shaft and slide it through the two loose gears already placed in the case and down into its bearing.

With a hammer and punch, drive out the pin that fastens the fork and shaft together of fork L. Slide the shaft out, and then hammer the pin back into the fork from the side shown in the pic, but only enough to keep it from falling out. Don’t let it protrude into the shaft hole. Note that the hole in the shaft where the pin goes through is not in the center of the shaft, there is a long and a short side.

Place fork L into the output shaft as shown. The letter L stamped into the fork should be facing up. Align the drum follower pin on the fork into the shift drum, it rides in the upper of the three grooves.

Slide the fork shaft through the fork, making sure you are placing the long side in first so the hole in the shaft will line up with the fork.

Using a punch, drive the pin into fork and through the shaft.

It should look like this when driven all the way in.

Separate fork C from its shaft and then start the pin back into the fork as shown below. Again, don’t drive the pin so far in that you’re blocking the hole for the shaft. Now place the fork into the input shaft and align its drum follower into the middle slot of the shift drum. The letter C should be facing up.

Slide the fork shaft through the fork making sure all holes align. This fork shaft has its hole for the pin in the middle, so it doesn’t matter which end you put in first.

Drive the pin through the fork and shaft.

That’s it. You’re done. It should look like this.

You probably won’t be able to turn through the gears very easily because gravity and non-rotating transmission shafts are working against you. But you should be able to wiggle the forks through their path on the shift drum if you also wiggle the gears around. Let me know if you guys have any questions.

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Man this is the first time I've seen or heard of anyone actually doing the transmission this way. Looks like a lot simpler way to get them all where they go, with out need octopuses arms and a lottery worth of good luck.

3,008 Posts
Great write up, someone needs to do the same for the 450R
The R trans is much easier.
You can slide the forks in and then put the shaft through the fork.
There are no pins. So get the drum in, put the 2 racks, put forks on correct gear and in drum groove, slide shaft through forks. Done.

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