changing gearbox from bor cr2 to a 1018-006

The mechanic has lowered the motor and says it is still to high to line up. Has anyone changed the stern tube to get a higher pitch for realignment? The motor is a 200 hp Perkins. I need to raise the motor off the hull, reset mounts on stringer and raise the shaft by changing the stern tube (Shaft Log)

You might want to price rebuilt CR2's. Probably in the $2000 range. Might be a lot cheaper then doing major rework to change location of stern tube.

Couldn’t find one have had mine rebuilt twice. The rebuilders said the damage was caused by alignment but the alignment was done with feeler gauges on the flange to with in 2 thousands .

I did that on a clients boat when he could'nt locate a drop center tranny. The stern tube was removed and the engine, replacement tranny and shaft reoriented to the desired angle. The motor mount mounting plates were remounted to match new engine angle. The shaft was immobilized to keep it from moving out of position. The stern tube was covered with packing tape to avoid epoxy from sticking to it. . To make sure the shaft did not stick to the epoxy and to make sliding out easier, I wrapped foam around the shaft and covered that with packing tape.

A glob of epoxy putty was placed on the stern tube and the tube pushed against the dead wood and fixed to not move. Excess squeezed out putty is cleaned off and shaped. The epoxy putty was made with WEST High Density filler.

After the epoxy cured, stern tube and shaft was removed and the shaft hole enlarged in the epoxy wedge, cleaned up and any voids in the epoxy filled. Another epoxy wedge with the same angle as the one made on the outside is made in a mold and glued into the inside of the hulls deadwood to insure the bolts, washers and nuts on the inside were perpendicular to the inside face of the deadwood and parallel to the face of the new wedge on the outside.

The stern tube is slid back onto the shaft, holes for fastners drilled and stern tube installed with Life Caulk. The engine is checked for alignment and mounts adjusted if necessary.

The angle of the shaft did not change a lot so the epoxy wedge was 1/2" at the thick end. If a thicker wedge was required because of a greater shaft angle change, I might reinforce the wedge with fabric.

The top front of the engine touched the underside of the floor after reangling. I routed a recess in the plywood to clear the engine.

Also, the shaft on this boat was short and thick so there was no shaft droop. With longer shafts, a more careful alignment of the shaft prior to creating the wedge is advised.

Replacing the cutlass bearing with the stern tube off the boat is so much easier than on the boat so that is recommended. I use a press.

I had to pull mine and change the side to side angle on my old Mainship 34.
It was not that bad of a job, pretty similar to what is described above but I used pressure treated wood to make the new angle then epoxied everything.

I just had my CR2 rebuilt a few months ago. There was no problem getting it done. I am told there are two rebuilders in the Tampa area. I can call my mechanic and get the names.

CR2s are fully rebuildable. If the gear pack at the back goes bad they either have to use a gear from a private stash or have a new one machined. But they are rebuildable.

If you aren't set on replacing it with something else, I can call him Monday and get the names.

Already committed to the 1018-006 but thanks any way.7

rgrstff said:

Couldn’t find one have had mine rebuilt twice. The rebuilders said the damage was caused by alignment but the alignment was done with feeler gauges on the flange to with in 2 thousands .

Click to expand...

Then it wasn't within .002", you have a bent shaft or the motor was loose.
I align within .002", but most yards are too lazy and usually 2 or 3x less accurate. The really lazy ones add a plastic of fiber spacer in the flanges. I've been doing alignments since 1960 and never seen a failure from a .002" alignment.

New stainless shaft 1 year old. Just has been rechecked along with prop at pro reckon in Marathon. The rebuilt cr2 was done by 72 year old been doing this since he was 18 have replaced carrier bearing cutless, and shaft log

Is this an older Mainship? Mine was built 3/4 of an inch off center at the carrier bearing. It was aligned properly at the coupling and the problem was never noticed until I changed from a bronze shaft to a stainless shaft.
The stainless was much stiffer and caused some vibration where the bronze was compliant enough to run smooth.
Yes I also relocated the mid bearing.

Yes 1983 thanks