OMC-1956 30 hp motors -thrust washer on prop shaft question

[outboardnut]

I have had two 1956 30 hp motors this past year.
Both of them were missing the thrust washer on prop shaft.
Is the thrust washer on prop shaft really necessary?
What is the purpose of the thrust washer on prop shaft?
Has anyone found a washer at the hardware store that would work?

• This topic was modified 3 years, 5 months ago by outboardnut. Reason: to insert
• This topic was modified 3 years, 5 months ago by outboardnut.

[nj-boatbuilder57]

Very interesting question….I have a ’57 35HP and there is no room at all for this washer. With the prop all the way seated, if I put on this washer, I cannot get the drive pin through. I have numerous props of different pitches, including some that have been professionally re-hubbed…and not one of them will allow for that washer.

I put on the prop, insert the pin, put on the cap and put in the cotter pin….I’ve spent hundreds of boating hours spent that way, no thrust washer.

I can’t say if it’s required or not; I can only say that my engine simply won’t allow for one, and I haven’t suffered at all for the loss…

• This reply was modified 3 years, 5 months ago by nj-boatbuilder57.
• This reply was modified 3 years, 5 months ago by nj-boatbuilder57.

[outbdnut2]

I doubt you need it because it only gets stressed when in reverse. I have a 30 but I don’t remember if it has one or not.
Dave

[Bob Wight]

My ’56 30hp Johnson did not have the thrust washer and the prop fit really loose on the prop shaft. If you look at the parts listing detail, the thrust washer was only used on the RD-18C which also shows a different prop, prop drive pin and prop nut than the original RD-18 or RD-18E. So I assume the RD-18C was some type of revision during the production year that modified the original design. The original model/serial ID tag on my motor was missing so I didn’t know what model it was, but when I cleaned and resealed the gearcase, I ordered a thrust washer off Ebay, put it on and the prop seemed to fit properly.

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[johnny]

I have installed the thrust washer on all my motors that show it on the parts list. However, I don’t see where it really does anything at all. Once the drive/shear pin is installed the propeller can’t move in or out on the propeller shaft.

• This reply was modified 3 years, 5 months ago by johnny.

[dave-bernard]

not on the shaft BUT on the HUB it can.

[nj-boatbuilder57]

…on the hub it can….what?

[joecb]

If memory serves, and it sometimes doesn’t lately… That washer does serve an important function in the event of a shear pin failure. I’m trying to recollect the failure/damage scenario that is prevented by the presence of the washer…. maybe this will jog some else memory.

Joe B

[Mumbles]

I think it’s supposed to keep the prop from falling off if the drive pin shears.

• This reply was modified 3 years, 5 months ago by Mumbles.

[todd281]

I thought it was to keep the prop from jamming the shear pin after a prop strike, The prop can move on the rubber hub, if the prop strips the rubber hub it can spin and move, if it happens the prop can slide rearwards capturing the shear pin. In this situation you have to find a way to move the prop forward while still on the motor, enough to remove the pin. I read about this somewhere on the internet, and sure enough I found some of my props would not allow the washer, and on the same motor, some would. I assume this is because, the props that would not allow the washer had been damaged by a strike and moved. they still would fit and seemed to work without that washer.

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