Simple Prop Removal Tool

[sgharford]

The full forward thrust of the prop is transmitted thru the thrust bearing. right? I would think if it could take 400hp+ of thrust it must be substantial and should be able to take a wack by hand held sledge pretty easily.

[J's Dream]

It's called a Prop Knocker...and it works very well. I kind of laughed at the idea when I first saw it. My friend worked for SeaRay's Product Development, and lent me the tool. I threaded it on the shaft, and hit it with a hammer 3 times like he said.

After I hit it, I unscrewed it, thinking what a stupid tool...it'll never get these props off...No sooner did I get the tool off, the prop was sliding off the shaft!

Needless to say, I was impressed...but still haven't spent the $100 to purchase one from General Propeller.

[Trojan]

The inursha has got to go and stop some place. That is all that the nut does is give you a place to hit.
I agree with Mike. That thrust bearing is designed to receive a constant rotating pressure. Any hitting on the bearing could cause a very small dimple in the bearing race or roller causing a premature failure. I don't like even hitting the end with the clamp type puller. The new props I have, have 3 holes drilled and tapped in the prop hub end. A special puller is used with these holes and just pulls the prop off. Very nice.

BILL

[saltshaker]

Then when the puller won't budge it the yard wacks it with a sledge.

Usually way too hard and continually. Seen that too many times to count. Seems that if used right, the nut buster would be less damaging.

[SKYCHENEY]

I have never had to hit this puller. I just keep tightening until she goes POP!

We made it up in the shop a few years ago. It will also push in/out cutlass bearings. Handy tool to have around.

[mike]

FWIW, angular contact thrust bearings are intended to take intermittent and continuous radial and axial loads, not excessive shock induced point contact. The amount of force delivered with a sledgehammer could well exceed the bearings material specs. Failure will not be immediate, but the initial damage will be done, and over time fatigue failure will occur. Check with any of the bearing companies (SKF etc), and you will see instructions on bearing installation cautioning to apply force only to the face of the non-loaded race. What may be easy for the yard can cost you big boat bucks. Have a homemade set-up similar to sky's using a 20-ton Hydraulic ram. It works well on both the props and the trans coupling. Further if you use the Tony Athens prop attachment method listed on the boat-diesel site, removal will be a cinch.

[ppat324]

Old faithful... ws

[captddis]

I am not going to debate for the next week, however I hate beating on things but I don't see how two wacks on the end of the nut is going to cause harm. The common way to pull shafts is with a 20 pound slide hammer. Onan and Kohler told you to use a hammer to shock the gen end off the shaft. Detroit diesel uses a sledge to shock off the harmonic balancer and cone.

What happens when a 60,000 lb boat hits bottom at speed or someone hits something hard and tulips the props or bends the shaft? That has to be a whole lot more stress on the bearings.

I have prop pullers too and often times they will not budge the prop even with a porta power maxed out to where the plates are bowing. Then go to heat, If that does not work then what? Oh yeah when using a puller and the prop comes loose and hits the nut on the end of the shaft with a violent clang, does'nt that send a shock up the shaft?

[Brian Degulis]

A properly fit prop that's been lapped on installation then tightened to spec which on a 2 1/2" shaft is over 800lbs of torque is never coming off without shocking (hitting) the shaft unless you heat it. If your getting if off with the puller alone then it wasn't put on correctly it's just that simple.

Brian

[Nonchalant1]

Old faithful... ws

Bill,

That's the prop puller I have and use. It works fine, but if one gets stuck I'd have to go borrow/rent a hydraulic version.

Doug