prop removal

[Andrew]

pete knows his stuff!
i'd highly recommend taking heed to his advice

[Red57Bird]

I have no doubt Pete knows his stuff, but dont' you think that Acme knows a thing or two about props?

[Andrew]

maybe..... wouldn't be the first time that bad advice was put in an instruction manual though....

[8122pbrainard]

I never like to contradict what it says in a manual. Lots of thought has gone into it but it sure would be interesting to see what people at Michigan Wheel or OJ would have to say. From a mechanical engineering standpoint as well as learning way back when Michigan was pretty much the only one out there, the taper should be dry. BTW, I've been around longer than Acme has!!!!

I'd like to add to how tight the taper can hold a prop on. Many a time when tightening the nut, the castillations will not line up with the hole for the cotter pin. The nut is then actually loosened till you can get the cotter pin in!

[jos]

Nice topic,

Not the first time. the nut isnt pushing the prop all to the end, but only the end off the treath, so locked on the shaft and not locked to the prop.
You should check that with every other prop.

So you should have some spacers.

Another great thing about spacers, the will help you to load the taper.
And it will also help you to, more easy, line the cotter pin

Ever tought why your hole rig has a spacer under every nut? It lessens friction between the nut and the block, so the torque comes as it is ment.

Check the nut tension once after, you have had a nice day.

[8122pbrainard]

57, You really peaked my interest regarding the lubricant on the prop/shaft taper. I did two things: I called Acme and spoke with Jim. He told me there reommendation is more for a corrosion inhibit so a VERY light coating must be used. He agreed that 80% of the HP/torque is through the taper so great care must be used. It is a option and will aid in prop removal IF there is a issue with corrosion. A good puller is a must after the prop is properly seated on a well fitting taper. I also did a search and googled prop installation. I found some very good instructions but only read about 5 of them. Interestingly, lubricating the taper only came up on one of the instructions and it was a no! Here it is:

http://www.propscanusa.com/propeller_checklist.htm

7. Install propeller

"Install the propeller with the key fitted to the shaft. Some people prefer to use a lubricant on the shaft, we do not recommend this."


Jos, Tell me more about you having a problem of running out of threads on the shaft and not being able to set the prop properly on the taper. In 42 years of installing props, I've only seen this once and it was a bad prop that the taper had been reamed deeper.
Also, you may have missed it but I asked you explain more about people putting hydraulic oil in their engines. It's in the tail end of the thread on oil in gearboxes. I just found it hard to believe that some one would do it! I did however see a engine that the ower had filled to the top of the valve cover with engine oil and then wonder why the engine wouldn't turn over!!!

[Red57Bird]

Pete - OK, I did some Googling myself and I saw numerous mentions about using the valve lap compound to ensure a good fit with the taper. I'm new to inboards and I just realized that the key is a separate item. I thought that the shaft itself had a key already machined in and that the prop just slid over it. I seem to learn something new every day I check this forum, which is why it is so helpful. So I'll take your advice and forgo the light grease.

So, can you explain the exact process for using the key and installing the prop on the shaft? What I mean by exact is do you slide the prop on the shaft and then insert the key, or do you put the key in the prop as you are sliding it on the shaft?

I'll be up at the lake house this weekend trying to change props and I don't have a phone or internet access up there. Thanks for the help.

[8122pbrainard]

57, The biggest problem people have is not getting the prop fully seated on the taper because of a cocked key. To make sure the prop is completely on the shaft, put the prop on by hand first without the key. On the shaft, mark the position of the forward edge of the prop hub. When you set the prop, this mark will then tell you the prop is fully forward on the shaft. Put the key on the shaft and slide the prop over it. Start snugging up the prop nut and lightly tap the hub with a block of wood and hammer in several spots. Snug up the nut again and if you are using a castle nut, put the cotter pin in.

BTW, use a brass nut on the stainless shaft rather than a stainless nut. With stainless to stainless, you are taking the chance that the threads will gall locking up the nut to the shaft. I have had to cut off stainless nuts with a die grinder and friction blade and then chase the threads with a die just to save the prop shaft.

[Red57Bird]

Thanks - makes sense. When I got my new prop I also got a puller kit with a new key and brass nut. Is it possible to use the old key and nut, or should you always use new ones? I know to always use a new cotter pin, just wasn't sure about the key. Thanks for the info.

[richard]

Prop remove

I had change 4 piece prop shaft,(now the 5th on my 01SAN),everytime I need a puller,some times easy out some times realy hard,take care the prop will pop out strongly and cut your hand so don't remove all the locknut,(just loose a couples mm,)this prevents the prop falling.every time I don't use grease or anti c's.

[8122pbrainard]

RE: Prop remove

57, the old nut is fine. The old key is fine too as long as it fits nice and snug in the shaft key way.

Richard, where are you running the boat?? It sounds like (and looks like) you sure go through the props!!!

[richard]

Prop hit stone

Hong Kong,I run the boat in sea,near Island and coast,there are some stone located at the place they should not,every time I hit them when low tide or night,I hate them and my self and marine department every time I hit the stone cover by water,marine dpt should remove them from near drive way or make sign easy but they never take care.

[SPBFAN]

Lap your prop into the shaft and put a very small amount of Anti Seize onto it when you are done you will be surprised at how well it comes of next time and at the very minute vibrations that go away. I have replaced a lot of props for people and I always do this.

[SPBFAN]

Re: Prop remove

I had change 4 piece prop shaft,(now the 5th on my 01SAN),everytime I need a puller,some times easy out some times realy hard,take care the prop will pop out strongly and cut your hand so don't remove all the locknut,(just loose a couples mm,)this prevents the prop falling.every time I don't use grease or anti c's.

Take a 2X4 wrap it in a towel and put it between your prop and the bottom of your boat. It will keep the prop and shaft from spinning thus allowing you to get better pressure and torque on the prop to remove it from the shaft easier.

[8122pbrainard]

put a very small amount of Anti Seize onto it when you are done you will be surprised at how well it comes of next time I have replaced a lot of props for people and I always do this.

SPB, Please read the complete thread and make some phone calls to the prop manufacturers.