Here's a start, Scott.




I don't know if you've taken anything apart yet, so I'll start at the crank.
Look at the side of the crank boss, where it attaches to the camera, and you'll see
a pin holding it on.  One end of the pin is smaller than the otherside.  Drive it out from
the smaller end and you will end up with what is shown above.

Follow the next four pics, and take off all these round things.
























At this point, peel off the leather and take out the screws holding the side plate.
Then take off the plate.

At the location of the top winding key, that goes through the camera body to hold the top
film spool, you will see a flat spring washer.  Often, it is stuck to the side plate with grease.






Things will look pretty much like this. 





A couple notes about this shot;

A, is the winding key that goes through the camera body and into the film spool.
It should have the flat spring washer on top of it.  This gear/key is just sitting in a
hole and will pull out.  Just to the left of it is a ratchet that is spring loaded that keeps
the key from turning backward.

B, is the main drive idler.  It's held on with a screw.  The screw is usually LEFT hand
thread.  It will have to come out if you need to take the winding clutch apart.  Lets hope not.

C, is the counter drive gear.  It is on a moveable pivot.  It will be in different postitions
depending on whether the camera back is open or closed.

The red arrow is just to point out the little washer.  Watch for these in any place that
a screw went through the side plate.  They are not always on each hole.  They hold the
side plate up a little so it doesn't rub on the gear works.

The red oval circle is where I hope your trouble lies.  See next pic.





These two small points must be aligned well.  The point on the left lever
lifts the point on the right lever when you wind the camera, which releases
a locking ratchet under the larger metal disc.  That metal disc is the clutch.
I should say, I call it a clutch.  I don't know what Yashica calls it.  It has
two drive ratchet pawls that lock and drive the main gear in one direction,
and let it free wheel in the other, like when you wind the crank backwards.

If  you put a dummy roll of film in the camera, close the camera back,
and wind, then fire the shutter, you can watch what all this stuff does.
Hold down the drive key with your thumb while you do it, or it will pop out.
As you wind, if the counter is working right, and the points on these two levers
are aligned, (not bent up or down) things will work properly.  I've found these points bent, so one
rides over the top of the other, and then the camera will lock a short way through
the winding cycle, because the locking ratchet locks the clutch. 

Also, each of these two levers are spring loaded.  If one of the springs is off,
or bent so it doesn't put enough pressure on the levers, one lever will skip over the top
of the other lever before it's supposed to. 

If you see one of the levers slipping past the other and letting the wind crank lock
before it winds all the way, find the cause of that, and you will probably be done
with this problem.  Look for loose or bent springs on either of the levers, or for
one of the levers riding over the top of the other.  At some point in the winding
cycle, one of them does pass the other, normally.  If one of the tips is bent up, one
lever will actually trip before the wind cycle is complete.






This shows the function of the pin you see sticking into the back of the camera when you
open the back.  It resets the counter.  This shot shows the works with the camera back open.
Starting at the lower right;  When you close the door, the back pushes on the pin, moving the
long flat rod that releases pressure on the lever upper right.  That lets the long rod at the top
move left, which moves the long lever at the left, which engages the compound (double) gear
at the end of the arrow point.  That causes the gear to mesh with the drive key gear, and the
counter will work as long as there is film in the camera. 
When you open the camera back, the reverse happens, disengaging the compound gear from
the drive key gear, which lets the spring loaded counter wheel return to zero.

A lot of explaining, but if you have to take the drive clutch apart, you need to know this
function, because all that stuff has to come out.






This explains the wind cycle further.  The large disc is the clutch.  The dog attached to it, (XX) is the
thing that trips the two little levers that lock the wind handle.

I need to tell you what #3 is first.  That is where the notched counter pawl disc normally sits (see next pic), under
the numbered counter.  The notches in that disc engage the end of the large lever (3) when the film has
advanced one frame.  It knows when one frame has gone by because it is geared to the film drive key.

So, the dog, (XX) travels the path of the long red arrow., and it holds the long semi-circular lever
out as it travels through its arc.  When it passes the end of the semi-circle lever, the spring on the lever
pushes the end (3) toward the counter pawl disc.  The outside of the counter pawl disc holds the lever
up until (3) falls into one of the notches.  At that moment, it pulls lever (1) to the left, letting the point on
lever (2) slip past, and lock the handle, which is what it's supposed to do, once one frame of film
has been advanced.

Note, lever (2) has an arrow point to under the clutch disc.   Actually, the pawl that locks things
is under there, and it is one piece with the #(2) lever that rides against lever (1).  Hope that's clear.

When you wind the crank handle backward to return it to its resting place, the dog (XX) slides
up and over the large semi-circular lever, since the lever has now slipped into one of the notches
of the counter pawl, and is flat against the clutch disc.





If you do have to take it all apart to get the clutch out, (hopefully not!), here's how to do it.

Remove the counter disc.  Pull it straight up, and watch that the bottom half of it doesn't get
stuck in the large brass disc (top center).  The large brass disk with the notches in it is the
invisible counter pawl disc I was talking about in the previous pic. 
The bottom half of the counter is a small disc that fits in the counter pawl disc.  It has a spring
inside it, so make sure it is not stuck inside the counter pawl when you remove it, or you'll
stretch the spring.

You can take the drive key gear out before or after you do this.  There is another drive gear
shown in an earlier pic that is half way under the counter disc.  It just sits there.  Pull it out.






Now you need to remove the counter engagement linkage.  Start at (A).  Remove that spring, or just watch
that it doesn't fly when you take out the two screws.  The other two lines at (A) are screws, (one has been
removed already).  Take out the screws, lift the link up slightly, and then toward the front of the camera
and take it out.
Then remove screw (B).  Sometimes the rod attached at that screw will now come out by slipping it
off the end of the long crooked rod at the far left.  If it doesn't, take out screw (C) and remove the
spring under it, and take out both rods.







Then take out the screw in this picture and take off the spring attached to it.  Then take off the
long curved lever.  When that lever is off, you can take out the screw in the gear the lower
arrow is pointing to, take out that gear.  This hear often has a LEFT hand thread on the screw.






Now, turn the crank boss so you can see the thing in the large circle.  Just note it well.
It is on a cam that is screwed into the back side of the clutch, and it mates with a lever that
does the actual cocking of the shutter.  Just know that it is there, so you will realize how to
put it back in order when you reassemble.
Take the screws out of the small circles, and you should be able to pull the whole clutch
plate straight out.


If, after you've come this far and you need pics of the clutch, I'll do another page.  I'm
hoping your problem is just the two little pointed levers described above.

Dean