1200S: service time, part 3

TRANSMISSION

Oh boy, this was the big one, the reason I stopped riding the Sportster and took it into the workshop in the first place. It's finally time to get into the transmission and sort it out.

While the fluid drains, I remove the left-hand footrest and the gear lever. The latter is mounted on a spline of the shifter mechanism (or "shift-shaft" if you prefer that tongue twister), and care must be taken whenever dealing with splines: they're a great engineering solution, but they're also rather delicate if mishandled. Don't whack them, don't twist, don't pull... easy does it.

The footrest is very interesting in that it is bolted directly into the crankcase (through the primary cover): it was done this way as there simply is no room between the engine and the frame rail to weld a bracket onto the frame in a way that would make it sturdy enough, and while to some people it may seem crude, I think this is a pretty cool detail (albeit a potential source of vibration at high speed).

Then, collapse the clutch cable adjuster so the cable is completely slack, remove the clutch "derby" cover which is held on with confounded Torx screws (being careful not to drop the lockplate and spring assembly that keeps clutch adjustment, more on that later), then it's over to the primary chain tensioner underneath the cover to slacken that too:

At this point you can remove the clutch actuating mechanism: you do this by carefully lifting out this nut/spring assembly:

then backing out the actual adjuster shaft so you can free its retaining nut and lift the actuator out.

Everything was in "as new" condition, although looking closely at one side of the actuator, I had to wonder if it had been damaged somehow, as you can see evidence of a missing tab of some sort, and a rough edge. From a quick internet search and a look at the parts diagram, it would appear this is normal however, and possibly due to the manufacturing process for this part.

Being used to fairly crude "pushrod" systems on a variety of other bikes (BMW, Norton, Matchless, Triumph, BSA, and the Morini too, I think) this seems over-engineered, and there is certainly reason to open this up, clean, inspect and reassemble the unit to ensure proper operation. The service manual does say that the internals should be packed with a small amount of grease. Everything looked good so I applied a small amount of grease and left it at that.

There is no reason to remove the clutch cable fully, the primary cover can be set aside while you work on the transmission.

I used the old gasket to keep track of where each allen bolt goes, as there are different lengths and I don't know these off by heart.

The service manual does obviously help with this, in the form of a handy diagram:

There are also two locating dowels, fore and aft of the primary chaincase: don't lose them.

The biggest surprise came when I looked inside the primary case to discover a pristine environment that truly looks like it just left the manufacturing facility: this thing is literally spotless.

This is turning out to be a very long post, so:

TO BE CONTINUED...