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  #1   IP: 24.53.89.131
Old 06-06-2018, 05:21 PM
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Peter Peter is offline
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bent shaft

Hello all,

Looking for some advice. Late last season I noticed I had an oil leak at the back of the reversing gear and a rather unpleasant sound when the boat was put in gear. Also had a dripping water pump.

This spring I hoisted the motor up into the salon and performed the repairs - replaced rear seal, replaced thrust bearing and rebuilt water pump. The old thrust bearing was a little gritty feeling and the spring on the oil seal was broken.

The MOYER tech tip video on the rear seal replacement was excellent and made the job go very smoothly. I also installed new motor mounts.

Put engine back onto the mounts, did an alignment (which was a dream with the new mounts) and all seemed to go well.

Today was launch day. Engine started right up, no oil leaks and no dripping water pump. Popped it into gear and no unpleasant sound. The old thrust bearing was a little gritty feeling.

However, a bit of a shudder when I applied some throttle. Go the boat to my slip and went below to see what was up.

Shaft coupling is nicely mated to the output coupling on the engine and no wobble there. But, the shaft was wobbling in the stuffing box... There was no vibration last season. The video below shows how much wobble there is.

https://youtu.be/PjvFHR7Ea7E

(Apologies - I tried to embed the video following Bill's instructions found here - http://www.moyermarineforum.com/foru...67&postcount=1 but no luck.)

I have two theories about how the shaft came to be bent.

1) We could not get the shaft coupling off the output coupling and we broke it free when we lifted the engine. In retrospect we should have tried harder by tapping on the prop close to the shaft.
2) I installed a new zinc and my yard guy told me to hammer it on to make sure it was well seated. The hammering did indeed allow me to get more turns on the zinc bolts but maybe induced the bend?

I have a 3/4" shaft and I think it is perhaps bronze?

Questions:

1) Can I live with this for this season or will I be buggering something up - cutlass bearing? My motor usage is motoring in and out of the harbour - 10 minutes tops each way.

2) If the answer is no, and we assume the damage was done when the engine was lifted, what about rotating the shaft until the high point is up and trying to "tap" the shaft down with a largish hammer?

Looking forward to your wise council!

Thanks,

Peter

PS - boat is a 1976 Ericson 29

Last edited by Peter; 06-06-2018 at 05:42 PM. Reason: spelling
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  #2   IP: 172.95.97.58
Old 06-06-2018, 05:49 PM
Dave Neptune Dave Neptune is offline
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Peter, the shafts on most of the Ericsons were 3/4 stainless. If it is stainless it can probably be peen straightened. I have straightened quite a few over the years.
I left the boat in the slip while doing so. First get a short piece of "shaft" or a 3/4" diameter aluminum or even plastic. The shaft can be pulled right out the back and the short piece inserted into the log to plug the leak. With the shaft in hand it could be an easy decision on straightening or replacing.

If it is a bronze shaft I would not attempt to straighten just replace it.

Dave Neptune
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  #3   IP: 142.177.130.230
Old 06-06-2018, 06:22 PM
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Thanks Dave

Confused on how to get the shaft out with the boat in the water. Would I not have to drop the rudder and possibly remove the zinc?

Peter
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Old 06-07-2018, 02:03 PM
Dave Neptune Dave Neptune is offline
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Peter, I've done a couple of the 35's by just turning the rudder to the side with the prop still on. You may have to take a look and possibly pull the prop first. If not it's out of the water.

The concern is not shaking to much loose if running easy but shaking the strut loose is a biggie.

Dave Neptune
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  #5   IP: 24.53.89.131
Old 06-11-2018, 06:03 AM
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follow up - removed shaft coupling from engine and rotated shaft by hand - no bend. Seems I did not have the coupling properly seated on the output flange.

I have improved that situation and the vibration is largely gone. However, the coupling is still not fully seated.

I tried some emery cloth on the engine coupling but no luck. The shaft coupling is pretty close to the engine coupling so very difficult to access the inside of that for cleaning.

I had the bright idea of trying some lapping compound and then turning the shaft by hand until it went on fully. Very limited progress after several hours of lapping, but some pretty spectacular bruises on my arms!

Will next make up a tool that will allow me to scrape the inner surface of the shaft coupling - a narrow scraper with a "hook" sticking out one side.

Hopefully that will work. Will report.

Any other ideas?

Peter
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  #6   IP: 107.77.70.58
Old 06-11-2018, 07:45 PM
tenders tenders is offline
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You could horse around with the hook contraption for a while and then take it to a machine shop after you mess up one or both sides, or just take it to the shop now and have them fix it so you can get back out sailing faster.

The tool you want for messing up this fitment the most efficiently is actually a Dremel, though, and a carbide or diamond bit.

If the situation is bad enough that you thought the shaft was bent, I’d get thee to a shop, pronto.
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