Cutlass bearing dimensions: 30mm ID x 44.45 mm OD x 120mm L This is made by Vetus model# SPRULAGER 30 The outer dimension of this Vetus part is specified as 1.75 inches (which equals 44.45mm).
There is a set screw in the underside of the stern tube that holds the cutlass bearing. It is a recessed hex screw, but it will be revealed if you use a wire brush to remove paint from the stern tube at the bottom.
You can remove the cutlass bearing by carefully cutting from the inside with a reciprocal saw. I recommend you use a new/fresh metal cutting blade so that you get an even cut over the whole length of the long cutting surface. Two lengthwise cuts will allow you to start to peel back a section using locking pliers. Be careful not to cut into the stern tube, and go slow checking your progress frequently. Once you have started the bending of the cut section you can continue using cold chisel (with a light hammer) to extend the bend inward. Then compress the diameter of the cutlass bearing with locking pliers so it can be removed easily. Clean the inside with a moist scotchbrite synthetic scrub pad, rags and brush. Do not use sandpaper because you do not want to remove metal... Preserve the inside diameter.
There is not enough clearance to access the bottom hole with a drill unless you remove the aluminum propeller guard. So I drilled a new screw hole on each, and tapped the holes with threads for new set screws. This must be done BEFORE inserting the new bearing.
I determined that the bearing could not be pressed in (using a threaded rod) because the wall thickness of the inner shaft tube is thin, and I was concerned about distorting it. I froze the bearing for 24 hours before inserting it, to reduce it's size slightly, and lubricated the bearing with liquid soap before insertion. I used a 3 pound hammer and a block of wood, and it went in.
Alignment is critical from the start, or if you start it wrong you may ruin the new bearing.
After the new bearing is in its final position, you will need to use a drill slightly smaller than the screw threads to make indentations for the set screw. Do not drill all the way through the brass in the bearing, and do not tighten the set screws enough to distort the bearing shape.