Johnson RD-!8 prop pictures

[billy-t]

Hi
Can someone post a picture of the prop assembly, i have finally got the right prop nut, but the thrust washer looks too big, so a picture would be worth a thousand cuss words.

Thanks

[garry-in-michigan]

I hope this will help . . . 🙂

[billy-t]

Okay I am confused. I have a RD-18 1956 at first I tried a prop nut 376731 but that wouldn’t thread on far enough to put the cotter pin through the prop shaft, so I bought a 375773 prop nut and it threads on far enough for the cotter pin to be secured but with the thrust washer 304575 in place there is nothing to keep the drive pin from falling out of the propeller because the prop nut does not go on far enough to cover it and the thrust washer is to big to do anything to retain it.

Not sure what i am missing, sure would appreciate a picture of a prop with nut and thrust washer in place on a RD-18 to have a visual to compare too.

Thanks again.

[beerman57]

Your prop hub may have moved, but I’ll bet you won’t hurt anything running without the thrust washer. Think about it – what part knows or cares if the thrust washer is there.

My friend with the modern OMC V4 outboard running a high pitch prop uses 2 thrust washers to set the prop back a little, supposed to help performance.

[frankr]

Nothing very fancy about it. Prop goes on shaft, thrust washer goes on the brass hub that sticks out, then drive pin through the brass hub & shaft. If the drive pin would stay in, that would be all it takes to drive the boat. However, the drive pin won’t stay in, so the nut goes on, overlapping the drive pin so it can’t get out. Then the cotter pin to keep the nut from unscrewing.

Ok with all that said, beerman may be right, the hub may be spun part way out of the prop. That is the case if the thrust washer won’t fit between the drive pin and prop.

The reason for the thrust washer and long pin is to keep the prop from spinning right off the hub, unscrewing and taking the nut with it.

I don’t have the picture you are looking for, but here is the anatomy of the prop & hub assy.

how to take screenshots

[frankr]

Actually, there were two different length drive pins and nuts to accommodate them. Early pins were same length as hub diameter, later changed to long enough to stick out both sides of the hub (to prevent the prop from spinning off the hub). The nut for the long pin has a larger inside diameter so it can go over the long pin. Thrust washer is used with the long pin.

[billy-t]

Maybe i have the wrong prop or something, but the prop nut wont screw on far enough to keep the drive pin in place, maybe the threads are messed up need to get my glasses on and look more closely.

As Frank would say, any hoo, I appreciate the comments.

Thanks and have a good day

BT

[billy-t]

Got it together with right pin and nut, thanks fellows.

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