Hey Kevin,

Yes you have to remove the pistons first to split the
case.  This is actually a fairly easy task with the
proper tools that you can purchase from your local
Home Depot.

All you need is:
 - 3/8" thread-rod - buy a one foot length
 - 2 3/8" nuts
 - washers of various outside diameters
 - circlip pliers

There is a hole in the case of each side, on the front
side of the engine (side towards the rear of the car).
 On the driver side, the hole is for the waterpump.
For the other side, its a waterline.

The front pistons (towards rear of car) MUST be both
pulled out first, and later reinstalled LAST when you
put everything back together.

This is very important.  Put one of the 3/8" nuts on
the threadrod and try to push it through the circlip.
It should go through and catch on the wristpin unless
you got a nut with a large outside diameter.  If by
chance, it does not pass the circlip, either find a
smaller one or grind down the one you have.

Rotate the engine so that the piston so that the wrist
pin is aligned with the hole in the block.  Using the
circlip pliers, remove the circlip.  Push the
threadrod through the wristpin without the nut.  Using
a pair of pliers (I use needlenose visegrips) hold the
nut on the other side of the piston and thread the
threadrod onto the nut.

For the front pistons, you will need to place a large
sleeve (I use large sockets) against the block over
the threadrod so the threadrod sticks through the
sleeves.  Put washers as needed so that the other 3/8"
nut can pull the threadrod.  Then put on the nut, and
drive it.  It will pull out the wristpin.

Do this for all four pistons.  For the back two
pistons, you do not have to use the sleeve/socket, as
you have extra space from the previously removed
piston.

Good luck!

Z

--- Kevin Brunson <brunson@TANGLEDBANK.COM> wrote:
> Subject is a 1984 Wasserboxer.  I have all bolts
> removed and the case
> halves spread to about a 1" separation.  At that
> point the right side
> hangs on something (looking from the pulley end).
> Am I supposed to
> remove the pistons before splitting--and if so, then
> how?  The
> obstruction seems like it might be a ring, but I try
> to compress them
> by hand and it doesn't seem to help.
>
> I've searched the archives and other web sources and
> not found helpful
> instructions.  I have the Bentley manual on CD-ROM,
> which makes it
> difficult to use, so if it's explained there I can't
> locate it.
>
> Thanks,
>
> Kevin