SLXI Prop key sheared, 2 inches away

[derekt2]

Trying to remove a slightly damaged prop and I think the key is broken/locked.

I've gotten the prop most of the way off, but the last couple of inches are really tight. I'm using a puller and hammer and probably grinding the key over the shaft threads if I had to guess. I've tried sticking a small screwdriver in the key hole and hammering it either direction, no dice.

With the puller I'm past the point it can pull, so added a spacer but it's slow going. Going to try mapgas next, but I'm not sure it'll help since it's not "stuck", it's a busted key.

Any other advice? I'm trying to avoid drilling the key or cutting the shaft threads.....

Edited May 3 by derekt2

[PNWoke]

Mapgas should expand the prop and theoretically could release the bind between the prop and the key/pin. 

[justgary]

It looks like you have about 1/4" or so to play with in the groove.  Did you try a BFH and a punch to try to drift the key forward a bit to unlock it from the prop and shaft?

[Bozboat]

A four blade prop on a SSLXI?

[SkiPablo]

Would suggest some PB blaster,  the put the nut back on and give it a few turns.  The more blaster and hit it with a mallet a few times and let unit sit 30 mins before trying again.    If that does not work make sure the nut is on at least 3 turns and drive it around a but.  That might loosen it up.  

[derekt2]

Success! Mostly. Prop is off - did some pb blaster and repositioned the puller and pounded on the key with a hammer and punch from stern to bow direction like you all suggested. Didn't end up needing the heat. 

The key is now stuck to the shaft.....banged on it from a few directions but it looks pretty rusty. I soaked it in wd40 and will try again tomorrow.

@Bozboat the 4 blade was a acme 579, not sure why it was on there, but I'm excited to try my new acme 525!

 

[Steve B.]

Wow. Good job ! I'm wondering if heat will still seperate those two metals. As far as a 4 blade, if I recall some folks tried that to make the prop wash more like a Response? Fine tuning the boat for slalom course use.

[SkiPablo]

Nice.  The 525 will really wake up that boat.  I run it on my SSLXi

[dalt1]

Is that  steel key stock? Needs to be brass.

 

[justgary]

Now use your punch again, or a cold chisel, to strike the end of the key with an outward angled blow to lift it from the slot.  Once it comes up at all use a small punch or cold chisel and tap it between the key and shaft at the bottom of the slot.  You may need to grind a point on the punch.  Even a 12d nail should work after you get the key lifted at all.

[Nick55]

2 hours ago, dalt1 said:

Is that  steel key stock? Needs to be brass.

 

Agree, it looks like steel, and likely the reason you had a difficult time getting the prop off.  You have good advice on removing the key from the shaft now that the prop is off.  Any marks you make on the shaft will need to be Emory clothed off too. 

[derekt2]

Huzzah! After 3 rounds of WD40 soaks over 12 hours, and 30 minutes of taps with a hammer and punch I have a clean shaft ready for a new brass key and prop. 

Thanks to the crew - doing some outward facing taps on the key were key. I cleaned it up a bit after removal and confirmed steel.

New key comes in a few days and I should be set. I was worried about the shaft strut, bushing and drive shaft but I have very little play in the shaft and had no vibration underway so I should be clear with just a new prop and a minor repair on the old. 

 

Edited May 4 by derekt2

[justgary]

You can run up to the local hardware store and buy 1/4" square brass rod.  Cut it to length and maybe file it a bit to ensure good fit.

[Steve B.]

Whew. Wonder if steel keys are used when you have a stainless prop ?

[dalt1]

1 hour ago, Steve B. said:

Whew. Wonder if steel keys are used when you have a stainless prop ?

No reason for steel unless want issues like he had. Non stainless steel guaranteed to rust and corrode till prop is seized. Stainless key better than standard steel but still not recommended.

[oldjeep]

19 minutes ago, dalt1 said:

No reason for steel unless want issues like he had. Non stainless steel guaranteed to rust and corrode till prop is seized. Stainless key better than standard steel but still not recommended.

That, and a stainless key would defeat the whole reason for the key - which is to shear if needed.

[justgary]

Yup, I use a brass key with my stainless props.