Really stupid question...positioning of thrust washer, '91 Force 70hp

[Cannondale]

OK, so I made the classic mistake and didn't write down, notate how the thrust washer faced on the prop shaft when I removed the old prop two months ago from my '91 70hp Force.

So, new prop and new thrust washer ready to install....but which way should the thrust washer face? Beveled side towards the prop or towards the gear case? I simply cannot remember.

Told you it was a stupid question. Thanks, though!

 

[carholme]

Re: Really stupid question...positioning of thrust washer, '91 Force 70hp

Cannondale;

I don't like to use parts manuals for correct positioning but here is a picture of your prop setup and if you use the + sign and blow the picture up a bit you will see the bevelled side facing the prop.

http://www.crowleymarine.com/mercury-outboard/parts/1460_0.cfm

If you have your old thrust washer there you can probably verify this by looking at the prop contact line on the bevelled side of it.

Not a dumb question at all, I do it all the time with the simplest things.

Gerry

 

[TwoFish]

Re: Really stupid question...positioning of thrust washer, '91 Force 70hp

I have a 98 75hp & the flat side of the washer goes up against the prop. The diameter of the thrust washer is the same as the centre if the prop hub. I haven?t had the boat from new but have had it serviced. Would have thought the mechanic would have noticed it if it was the wrong way around.

I?ll be interested to see what other people think.

 

[Rabbit 5]

Re: Really stupid question...positioning of thrust washer, '91 Force 70hp

I agree with TwoFish. Just took my 70hp lower unit apart and flat side of washer was towards the prop.

 

[TwoFish]

Re: Really stupid question...positioning of thrust washer, '91 Force 70hp

The Splines on the prop shaft are tapered. They flair out as they get closer to the gearbox. This stops the thrust washer in the right place along the shaft. I haven?t looked but I would think the centre hole in the washer would also be tapered to match. If it is tapered the largest side of the hole would go towards the gearbox & the smallest towards the prop.

Must have a look next time I have the prop off.