Cupped washer on Prop shaft

[bbook83]

In looking at the parts diagram for my 1974 1R drive, I see part 12-35965, described as a cupped washer behind the splined washer on the propeller shaft. There is not one there now and I don’t recall seeing it in the past. Some models have a continuity washer in that spot. Pictures of this part online don’t look like a continuity washer, but it may be zinc. Does anyone know if this a necessary part? If so, what is it’s function?

 

[Fun Times]

I believe that may be Mercruisers version of being a prop shaft seal protector for fishing lines getting caught up between the prop and gear case housing...If fishing line gets wrapped around the shaft it could cut into the oil seal and you'd lose the gear lube oil.

Volvo Penta calls it a line cutter, https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2386202.m570.l1313&_nkw=872082&_sacat=0

12-35965 for sale | eBay

Get the best deals for 12-35965 at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items!

www.ebay.com

It's wasn't listed in one of the service manuals for your drive number,

Boatinfo - Mercruiser Service Manual nr. 2 - 1974-1977 All Engines & Drives

boatinfo.no

Boatinfo - Mercruiser Service Manual nr. 2 - 1974-1977 All Engines & Drives

boatinfo.no

 

[bbook83]

Thanks for the link Fun Times. I have not been able to access the Boatinfo manuals before. You are correct that the manual does not show it. I saw it on the mercruiserparts.com parts drawing at item 81, part #12.35965. It shows it located aft of the prop, under the splined washer, so I don't think it is a line cutter. My outdrive serial # is 3587926, which is within the 2791957-489634 range of numbers on the parts diagram, but odly not in the 3780850-4893634 range for the manual, despite the year and drive type being correct.

I am pretty sure I have been running without it for years, so I am thinking I won't worry about it, unless somebody has another idea.

 

[Fun Times]

Further looking and reading over the notes available, it seems you'd have to use the cupped washer with an old different? designed propeller along with a different type of thrust washer for that type of prop.

Mercap Thrust hub 45451A1 & Includes washer cupped 12-35965
MerCruiser 45451A1 45451A2 Propeller Early 1965-69 Thrust Washer 120-160hp MC-1....((< plus many other drive models were listed too https://www.mercruiserparts.com/35965-washer ))....This would have been found on some early (1965-1969) MerCruiser Applications

• EZ Shift IA / IB / IC 1964-1966
• 120hp / 140hp / 160hp 1967-1969
• Basically this accommodates the Flat edge on the propeller shafts so this likely needs to still be used with early style MerCruiser Propellers

45451A1 THRUST HUB AND WASHER INCLUDED WITH Gear Case Housing part #, 1623-2511A5, https://www.mercruiserparts.com/45451a1-thrust-hub-assy .... Also sort of seen in the photo below.

Mercruiser Mercury Quicksilver Mercap Thrust hub 45451A1 & washer 12-35965 | eBay

Include washer cupped 12-35965.

www.ebay.com

MerCruiser 45451A1 45451A2 Propeller Early 1965-69 Thrust Washer 120-160hp MC-1 | eBay

120hp / 140hp / 160hp 1967-1969.

www.ebay.com

MerCruiser 45451A1 45451A2 Propeller Early 1965-69 Thrust Washer 120-160hp MC-1

Part Number(s) Included Mercruiser 45451 / 45451A2 / 45451A1 General Application / Compatibility This would have been found on some early (1965-1969) MerCruiser Applications EZ Shift IA / IB / IC 1965-1966 120hp / 140hp / 160hp 1967-1969 Basically, this accommodates the Flat edge on the...

www.nlamarine.com

1623-2511A5 NOS MERCURY MERCRUISER RECONDITIONED LOWER UNIT GEARCASE #1623-2511A5 for nos - Van’s Sport Center

Van's Sport Center has a large selection of marine parts and accessories. We have one of the largest inventories of obsolete and vintage outboard motor parts.

www.vansoutboardparts.com

 

[bbook83]

About the time you think you have the parts applicability figured out on the old units, you find something new. Thank goodness for the internet and the vintage NOS guys for availability. Thanks for researching it.