Tried to make this one single post with multiple pics as a follow-up to a previous thread, but ran into some sort of 5 picture upload limit. So...I'll try again, with several back-to-back posts. Sorry

 

Ok, some of you may have followed my earlier thread about my tranny pulley failure. This will be Part 2 of getting the bike back on the road. Beyond a doubt I had a pulley failure; spun the teeth out of the pulley



Got a new pulley for it, but I didn’t like the feel when I fit it on the main gear…too much wobble in my opinion. I couldn’t really see any similar damage to the mating teeth on 5th gear, but I followed the advice of several forum members that I ought to play it safe and replace the gear as well. My indy inspected it and had the same opinion. Being currently laid off, funds are pretty tight; so with the encouragement of some members and my indy, I’m jumping in and gonna try this one on my own. Here goes…

To replace the main gear, the whole tranny has to come apart, which will be a first for me. For the sake of brevity, the exhaust, top cover and side cover are already removed…all pretty much straight forward.

Before the gear train can be removed, the inner primary race has to be removed from the mainshaft. Normally this is simply pulled off the end of the shaft (by using the proper tool)…but…on higher mileage or higher HP motors, the race has a tendency to move inward towards the gear. That’s what I found, and therefore the tool couldn’t fit (between the gear and the race) to remove it off the shaft.

 

Under the top cover is the shift drum, which needs to be removed first. Remove the 4 corner bolts. With a small screwdriver, unhook the spring on the ratchet pawl. This will allow the ratchet arm to swing out of the way so the drum can be lifted out.



I lightly tapped the drum assembly with my rubber mallet to break the surface tension before lifting straight up. The drum is positioned using 4 small dowels at the 4 bolt locations. These often come out of their case holes when the drum is lifted. Be careful not to lose them, and return them to their holes

 

Remove the 3 shift dogs and their shaft next. Remove the shaft’s case allen bolt and then using that hole, push the shaft out the other side of the case with a small screwdriver.



Reach in and remove the 3 dogs; keeping them in proper order, put them back on the shaft and set aside.

Next, un-bolt the trapdoor (found behind the side cover). Reach through the top and engage a gear on both the main and counter shafts. This will lock the shafts and keep them from moving. Remove the throw out bearing.

 

Now break loose the 2 shaft outside lock nuts, but do not totally remove them. Take your dead-blow (only) hammer and lightly rap on the end of the main shaft. We want to move the shaft inward just enough (~1/16 - 1/8 inch). Go to the other side of the bike. This “slight” mainshaft movement will now allow the inner race removal tool to properly fit. Remove the race.

 

Remove the 6 trap door bolts and the gear train will now come out (all but 5th gear). DO NOT PRY on the trap door to free it, or you’ll most likely scar the case, which can cause a hard-to-seal leak. There is a dedicated notch on the front and rear side of the door designed just for this task.



There are also 2 more alignment dowels (like for the top cover). These mean the trap door needs to come off “fairly square”. I did not have the “official” trap door removal tool…I simply used my dead blow hammer again, and gently rapped on the end of the mainshaft…wah la

 

Last thing is getting 5th gear out of the case. I used a scrap piece of flat stock steel I had laying around and drilled a 11/16 inch hole in it, and used a length of 5/8 inch all-thread, washers, and an old lawn mower bearing.

 

5th gear should now fall into the case. Undo the all-thread and remove the gear…Done !



Cleaning up the gear and inspecting it closely, the damage from the spun pulley splines is now much more visible.


Thanks D_gyver, John, Spanners, and my indy Steve for convincing me to pull and replace the gear (I ordered an Andrews). The invoice said it’s supposed to be delivered Saturday, but the Tracking number says it’s still in San Diego…so, what should I do in the meantime? I know…take a nap !

 

the main gear bearing must be replaced when the main gear is removed. have fun with the big snap ring, it's not easy to remove unless you have a BIG set of snap ring pliers.

 

Great write up.