Prop won’t refit!

[Johno99]

Strange one this. I’ve got a 40hp 2 stroke outboard, I took the prop off last year very easily no problem and stored it in my garage, untouched for months. Today I uncovered the boat to start getting it ready, I cleaned the splines on the outboard and the prop and tried refitting. Half way down it stops with a solid clunk, I’ve tried cleaning oiling, nothing. All looks perfect but no go, oddly it will happily slide on freely the wrong way round. Inside the prop there is an inner section of splines, it’s obviously stopping on there but I can’t understand why. I don’t want to start hammering or causing damage to a perfectly good prop. Any suggestions please.

[Ribtecer]

How very strange.

Have you tried turning the prop a few degrees and trying again? Perhaps keep going until you've tied every possible option.

How many props have you got? Could it be the wrong one?

Really strange it goes on the wrong way round.

[Johno99]

I’ve tried, as you suggest, slowly turning the shaft a spline at a time, no joy. I’ve only got one prop so that’s not a problem. Really odd, I’ve had numerous numbers of boats and had props on and off and never come across this. Strange because the ends of the shaft and the ends of the mating splines are well chamfered so should fall on. I have photos and a video if I’m able to post.

[charliee]

Slide it on backwards several times, use a bit of lube (grease). Work it back and forth and then turn it round again.
Mark the starting point and rotate one spline at a time.
Have you hit a rock with a stainless prop, you may have twisted the splines.
Good luck

[Johno99]

I have tried as you say but I’ll have a fresh attempt tomorrow. It’s not a stainless prop and it wasn’t damaged. When I took it off last year it slipped on and off perfectly, I know because I cleaned the splines and greased everything up and slipped it on and off a few times before I stored it in the garage. Very strange. I’m struggling to find how I can post photos, any hints please?

[spartacus]

Originally Posted by Johno99

I have tried as you say but I’ll have a fresh attempt tomorrow. It’s not a stainless prop and it wasn’t damaged. When I took it off last year it slipped on and off perfectly, I know because I cleaned the splines and greased everything up and slipped it on and off a few times before I stored it in the garage. Very strange. I’m struggling to find how I can post photos, any hints please?

Thrust washer on the wrong way?

[Johno99]

Okay an update, I’ve found over the years if a job is proving difficult then walk away from it and go back preferably overnight. Anyway the prop has two sets of splines inside with a gap between the two. I’ve never known it before but because these are set in rubber there is a slight movement between the two sets of splines, I guess for shock purposes. I put the engine in gear and applying hand pressure and taking the prop on and off and twisting it slipped on. I can only think that while in the garage there was a slight setting of the rubber, temperature changes maybe. Anyway I didn’t realise the two splines were separate, I do now! Thanks for your help.