I'm half-owner of a Columbia 8.7 I swam to investigate a massive thumping and found about 1/2" shaft play at the Cutless bearing. The boat's now in the yard, where we saw that the bearing's hard-rubber inner collar is missing. So, we're replacing the Cutless bearing for the second time in 12 years. It required removing the rudder in order to draw out the shaft. We found the rubber collar several feet up the shaft, intact. It had separated from its constraining bronze collar for unknown reasons. The bronze collar is so frozen in place that the yard can't knock it out. Their mechanics are now sawing it loose. They showed me the removed shaft this morning. It's scored and pitted where the packing gland grips. The gland has leaked for years and requires tightening every few months. The yardmaster says that the scoring/pitting is probably due to excessive tightening - - and that leakage may continue unless a new, smooth surface is provided. He advises manufacture of a replacement shaft at a Baltimore machine shop. I told him to price it. He also says that the shaft should be shortened. At present, the open-air distance from the Cutless bearing to the prop is 5 1/2". He claims that this is too long, probably allowing some propellor-whip of the shaft. He speculates that whipping may be what worked the inner collar loose. He advises reducing the open-air distance to about 2", leaving enough for a zinc anode ring. No one will estimate how long the existing stainless steel shaft will last if I put it back in. It looks strong. The pitting is focused along 1/2" of shaft. The pits are randomly distributed full circle, with max pit depth about 1/32". My partner's age/health prevent him from sailing, and he doesn't expect improvement. As a result, we may sell the boat so that he can reclaim his investment. The yard's estimated cost is already about $970 for the hauling and labor of bearing replacement. I hope that you can provide me with some advice on the need-for/advisability-of manufacturing a new and shorter shaft. If not, where might I get such advice? Sincerely yours, Charles Boyle Annapolis, MD
- Status
Charles, If you are going to manufacture
a new shaft 3 inches shorter than the existing one, can the coupling end of the existing shaft be cut off and the shaft moved inboard the 3 inches? This would move the pitted area out of the packing gland and would only require work on one end of the shaft. It would also save the cost of the material for the new shaft.
a new shaft 3 inches shorter than the existing one, can the coupling end of the existing shaft be cut off and the shaft moved inboard the 3 inches? This would move the pitted area out of the packing gland and would only require work on one end of the shaft. It would also save the cost of the material for the new shaft.
8.7 Prop shaft
Perhaps your 8.7 is different than mine, but there is at least one and usually two set screws holding the cutless bearing in place. They are almost always obscured by fairing putty and paint. This may account for the difficulty in removing the old bearing. Has the yard checked your motor mounts and shaft connections? A small amount of misalignment could have caused the problem you're dealing with, and it could be a relatively recent development. Just a thought. It seems strange to me though that in 30 or so years, the length of the shaft didn't seem to cause any problems. Larry Wilson Columbia 8.7 AllAboutMe Richmond,Va.
Perhaps your 8.7 is different than mine, but there is at least one and usually two set screws holding the cutless bearing in place. They are almost always obscured by fairing putty and paint. This may account for the difficulty in removing the old bearing. Has the yard checked your motor mounts and shaft connections? A small amount of misalignment could have caused the problem you're dealing with, and it could be a relatively recent development. Just a thought. It seems strange to me though that in 30 or so years, the length of the shaft didn't seem to cause any problems. Larry Wilson Columbia 8.7 AllAboutMe Richmond,Va.
Shortening drive shaft
Thanks for the thoughts and ideas. If we shorten the drive shaft, the existing spline for connecting to the engine will need to be machined/extended to make up for what's cut off. I'll price this.
Thanks for the thoughts and ideas. If we shorten the drive shaft, the existing spline for connecting to the engine will need to be machined/extended to make up for what's cut off. I'll price this.
Shortening shaft
The yard's estimate for a new shaft = $230 The quote for shortening the shaft by 2" = $35 That includes lengthening the foreshortened keyway. I chose to shorten the shaft. We should be under sail again by this time next week. Thanks to all for your interest and guidance. Charlie Boyle
The yard's estimate for a new shaft = $230 The quote for shortening the shaft by 2" = $35 That includes lengthening the foreshortened keyway. I chose to shorten the shaft. We should be under sail again by this time next week. Thanks to all for your interest and guidance. Charlie Boyle
shaft too long
You mentioned having to remove the rudder post before being able to withdraw the prop shaft. How is that done? There is a brass block that the tiller attaches to on top of the post. It has a key (rusted). How does this block come off? Does it have to? I thought for a while that you could draw the post up out of the rudder, into the cockpit, and then just lift the rudder back from the bracket below. Now I see remarks about dropping the rudder which would involve removing the brass block and, in my case, getting the yard to lift the boat again in order to have enough clearance below. Why do I have to remove the prop shaft? It pulled out of the coupling and I need a new coupling and the shaft machined. Which brings up another question, why don't they have a hole drilled laterally through the top of the shaft whereby it can be bolted directly to the coupling? That would seem to be a better way of holding the shaft to the coupling than set screws and a key. But I'm no engineer.
You mentioned having to remove the rudder post before being able to withdraw the prop shaft. How is that done? There is a brass block that the tiller attaches to on top of the post. It has a key (rusted). How does this block come off? Does it have to? I thought for a while that you could draw the post up out of the rudder, into the cockpit, and then just lift the rudder back from the bracket below. Now I see remarks about dropping the rudder which would involve removing the brass block and, in my case, getting the yard to lift the boat again in order to have enough clearance below. Why do I have to remove the prop shaft? It pulled out of the coupling and I need a new coupling and the shaft machined. Which brings up another question, why don't they have a hole drilled laterally through the top of the shaft whereby it can be bolted directly to the coupling? That would seem to be a better way of holding the shaft to the coupling than set screws and a key. But I'm no engineer.
can't find the set screw(s)
Where exactly would those set screws be, i.e the one(s)that hold the cutless bearing in place? I've ground a fair amount of "meat" off from around the tubular area that houses the bearing and I don't see any screws. Are they Allen, Philips, or slot? The bearing is 4" long, correct? So, where in that 4" is/are the screws? Also what is the correct cutless bearing size for a 1977 8.7? Assuming I find the screws, what is the accepted way of getting the old bearing out once the pressure from the screw(s)is off ? Columbia Yachts doesn't answer my emails. You can reach me at my email address; dspease@rocketmail.com. Thank you.
Where exactly would those set screws be, i.e the one(s)that hold the cutless bearing in place? I've ground a fair amount of "meat" off from around the tubular area that houses the bearing and I don't see any screws. Are they Allen, Philips, or slot? The bearing is 4" long, correct? So, where in that 4" is/are the screws? Also what is the correct cutless bearing size for a 1977 8.7? Assuming I find the screws, what is the accepted way of getting the old bearing out once the pressure from the screw(s)is off ? Columbia Yachts doesn't answer my emails. You can reach me at my email address; dspease@rocketmail.com. Thank you.
- Status