shaft position concerns Morgan OI 41

sailnby · #1 (**permalink**) 01-04-2002

A buddy has a Morgan 41 OI and is concerned about the shaft trying to leave the boat when in reverse. He noticed shaft travel (fore/aft) of >3mm causing the concern even after tightening set screws. The carrier bearing is in alignment, properly adjusted and in good condition. The shaft brake doesn''t seem warped or out of balance. Suggestions to date have been to mod the shaft with dimples at the set screws, realign the engine, put a zinc on the shaft inside the boat (to keep it from flying out), change out the carrier and more. If you know of a proven fix I would sure like to hear from you. Thanks Greg

Jeff_H · #2 (**permalink**) 01-05-2002

3 mm (a litle more the a 1/16" I am rough guessing)is not extremely excessive. From the post it is not clear where the movement is coming from. Is the shaft sliding in and out of the coupling or is the coupling itself moving. If the coupling is moving it may be a worn transmission thrust bearing. If the shaft is moving it may be a wallowed out setscrew dimple. A hose clamp or zinc on the shaft is always a good idea as a safety measure should the shaft slip out of the coupling.

Jeff

Jeff

sailnby · #3 (**permalink**) 01-10-2002

The guy has decided to install a flexible coupler, with new engine mounts (the old ones are originals from 79). He mentioned there were no dimples in the shaft at the set screws, just scoring from the set screws.
Thanks for the reply!
Greg

Jeff_H · #4 (**permalink**) 01-11-2002

These are long term maintenance and upgrades that really don''t resolve the original problem of the shaft moving in and out o fthe boat. Beyond that, I have couple thoughts here, I hope that he understands that he will need to realign the shaft very carefully after replacing the engine mounts as there tends to be enough difference between old engine mounts and new that you can be assured that the shaft won''t be properly aligned. (Going to a flexible coupler won''t eliminate the re-alignment problem.) He will still need to cut a detent at the setscrews to prevent his shaft from sliding out of the coupling.
Jeff

Jeff

sailnby · #5 (**permalink**) 01-13-2002

When we pulled the shaft yesterday I was surprised to see dimples machined near the set screw position, and now am unsure what he was refering to by no dimples. The dimples looked to be in great shape, about 1/4" long and to me account for the slight slop between fwd / rev. We are replacing each motor mount one at a time, finding heavy corrosion of the anchor bolts. Very scary! New motor mounts are completely re-engineered, so we will be hyper critical with shaft alignemnt. Thanks for the info!