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Props & Prop Thrust Washers

The correct thrust washer MUST be used with your propeller or cavitation, or even worse, damage can be done to your drive.

Too thin of a thrust washer with the old style prop ( with the big thick rubber insert ) will allow the propeller to go too deep into the lower housing, causing the propeller to actually cut into the 4 3/8 carrier nut. This is extremely hard the gears in the lower unit.

Too thick of a thrust washer with the Black Max style prop will not allow the propeller to go deep enough into the lower housing causing cavitation. You will get to a certain RPM and the prop will free spin, making you think the prop hub is bad.

Early Style Props

If the back of your prop looks like this where you can see a large rubber insert, then you have what is known as the early style propeller. Michigan Wheel refers to these as the SMC series. Some people call them Elephant Ear propellers. These props and thrust washers were made from 1965 thru 1982.

Note ! These propellers are no longer available from either Michigan Wheel or MerCruiser.

This is the correct thrust washer for the early style propeller. It is .715 overall thickness ( a little smaller than 3/4 inch ), has a stainless steel outer ring and has 4 segments cast into it.

: Order # 6292

Black Max Series Props

If the back of your prop looks like this where you only see a large metal insert ( no rubber showing ), then you have what is known as the Black Max series propeller. Michigan Wheel refers to these as the PM series. These props and thrust washers were made from 1983 thru Date.

This is the correct thrust washer for the Black Max series propeller. It is .430 overall thickness ( a little smaller than 1/2 inch ) and is made from a solid piece with no stainless steel outer ring.

: Order # 3171

Vortex & Black Diamond

If the back of your prop looks like this where you only see a large square hole ( no rubber or metal showing ), then you have what is known as a Flo-Torq style propeller. Michigan Wheel refers to these as Vortex propellers and MerCruiser calls them Black Diamond ( formerly Typhoon ) propellers. These props and thrust washers were made from 1990 thru Date.

This is the correct thrust hub kit for the Vortex & Black Diamond prop. This thrust washer is also .430 thick but is a little smaller in diameter.

: Order # 5257

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Shelby Township, Michigan 48316

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Last modified: May 09, 2008