Johnson QD Prop Hub

[steeleman]

I was out on the lake with my 1963 QD yesterday and ran about half the day without problem, but then it began acting like it was popping out of gear at WOT. The shift level never moved and it never jerked back into gear. I have experienced this on my 1968 Merc 650 and it was a prop hub, which I had two props for so it was an easy fix.

So my question is, do these little 10’s have a rubber prop hub as well? And how should I go about fixing it?

[chris-p]

Sounds like your clutch dog and or forward gear is shot.

[Mumbles]

Your QD does have a rubber hub and it’s easy enough to check it’s condition.

Just remove the prop and mark the hub and prop with a felt marker on the front of the prop and reinstall. After running the motor again, remove the prop and look at the marks. If they are out of line, the hub has been slipping.

[frankr]

quote Mumbles:

Your QD does have a rubber hub and it’s easy enough to check it’s condition.

Just remove the prop and mark the hub and prop with a felt marker on the front of the prop and reinstall. After running the motor again, remove the prop and look at the marks. If they are out of line, the hub has been slipping.

Exactly. But you don’t even have to remove the prop to mark it. Use the cotter pin in the prop nut as one mark and mark the prop aligned with the pin. If it slips. the shaft/nut/cotter pin will spin inside the prop and marks will no longer align.

It’s a pretty safe bet that is the trouble.

[steeleman]

It is bad 100%. I can get it to slip with by bare hands without much effort at all. I have big press i could use. Is there somewhere I could get a hub and press it myself? or what is the best repair method?

Thanks guys

[Mumbles]

It’s best to let a prop shop repair it as special thimbles are used to press the hub in.

In a pinch. holes can be drilled from the outside of the prop and stainless or brass screws ran into the hub itself. A prop from a later 9.5 will also fit right on your motor.

[garry-in-michigan]

A rubber clutch is used in the hub of many motors to ease the shock of shifting as well as hitting obstructions. These outboards use a stainless steel drive pin. The slippage torque varies with the horse power. The propeller hub should be replaced on your motor if it slips at less than 84 foot pounds of torque. It should also be replaced if it does NOT slip at 104 foot pounds of torque. If you choose to "lock" the clutch with the three screws as suggested, you should also switch from the steel drive pin to a brass shear pin. . . 😉

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