Popping shaft bearing

[Kwadrant]

I have been trying to locate a strange vibration with noise in the engine train. Changed damper plate and shockmounts. Still in stationairy forward or reverse a fast bonking sound comes from somewhere. I suspect that the prop shaft bearing outside is done. Does any1 have the dimensions for a 1" shaft ? Are these conical ? Easy to replace?

Thanks for answering!

[drrot]

They are straight. Sold by size. inside diameter and outside diameter.
Do both your engines turn the same way?

[Kwadrant]

Ok i`ll dock the ship and try push them out.

indeed;
Both engines and gearbox do Jim. I wish to change to inturning as soon as i find a bronze 4 blade RH 13". Last previous owner issues im facing

[Doug P]

Jim, Would a cutlass bearing make this noise? Are both screws counterclockwise?
Doug

[farupp]

While you are removing the props it might be a good idea to have them checked for balance and have the blades trued. That will insure that the props are not causing any vibrations.

[Captain Nemo]

You can usually tell when your strut bearing is worn by grabbing onto and shaking the shaft at that point. If you feel any movement, the bearing is worn. It is easier to remove these using a hacksaw by taking the blade from the frame and inserting it thru the hole where the shaft was removed and reattach the frame and carefully cut a section of the bearing out. It should just about fall out then.

[Kwadrant]

Thank you Nemo, nice tip. Props are new, both turning CCW is a matter i wanted to change later if i only could find a good RH. im almost sure it is the bearing. Only stationairy forward gives this harmonic vibration. Full ahead its still there but way less.

[joanroy]

This type of low speed vibration could be a loose shaft coupling set screw or transmission noise.
The rebuilt Paragons in my 36 tend to be a little noisy until I bring up the RPM's a bit. I'm told this is normal. While your at it I'd check shaft allignment as well.

[Kwadrant]

Thanks Joan, actually i completely changed the drive train already. New mass ring (heavier) on flywheel with 5 fase damper plate. I wanted a slightly more heavy flywheel for better efficiency at lower speeds. Then i did a full revision on the Paragon P31. Reinstalled everything, aligned shaft which turns very smooth. I then checked stationairy forward and reverse again and noticed not to much difference. So i turn to the bearing outside. I visualized this in mind being slightly worn and turning slow stationairy forward, it must be this noise. And im so stupid to not check for clearance last year when i had the ship docked.

Thanks for thinking. I will offcourse let you know findings after changing the bearing !

[evansjw44]

Paragons tend to be a bit rattly at low RPM, especially at idle. The noise is the planetary gears flopping around and slop in the reduction gears if you have them. In one case the noise was the result of the V8 engine idling on 4 cylinders. That is the result of a plugges up idle jet in the carb. The intakes are set up so that half the carb feed half the cylinder and the other side feed the other four cylinders. Most CC V8s will idle nicely on four cylinders.

[Kwadrant]

I pulled the boat and took out the shaft and bearing. After looking at the shaft on the floor, i rolled it over the concrete with my foot. I noticed the end was spooning a bit. So i have a little bend prop shaft which causes troubles i think.

So i am sourching a machine shop to make me a new one. Unfortunately in Europe all tapered ends are metric and i need the imperial dimensions. (D=1" and L=60') Could anyone help me on a drawing for USA 1:16 Cone end ?

Thanks!

[jim g]

The space between the back of the prop and the strut should only be the diameter of the shaft. if you have to much space and heavy props you can get some vibrations from the shaft flexing on the end. A machine shop that can make shaft should be able to measure your old one to make a new one.