Rudder Stock Shaft Key

[whiteshythe]

Hi,

Am trying to change the rudder lip seals on my 13year old HR39.

I am having a big problem removing the Shaft Key ( Woodruff Key)

There is no gap between the end of the key and the slot in the rudder stock so I cannot get a good purchase to lever it out.

Have tried heating it up without success.

I have tried drilling and tapping a bolt radially into the key to try and prize the key out of the slot but not sure if I have gone deep enough. I do not want to damage the shaft.

Any suggestions very welcome.

Regards,

Steve.

 

[Norman_E]

A Woodruff key is designed to be a perfect fit in a semi-circular slot made with a special cutter. The usual method of getting them out if they are very tight is to use a cold chisel. The idea is to angle the chisel so that it cuts into the key just above the shaft and without damaging the latter, enabling the key to be levered out. It can be quite hard to do especially if you can only get at one end of the key.

As you have drilled in already, look at this website to see the proportions and dimensions of standard keys. This will enable you to calculate how deep to drill.

 

[clausewitz]

I have same problem with my HR36 from year 2000. Shaft key is totally stuck in place. I have tried heat, hammering, slide hammer on top and griping with tongs.

Next stage is drilling and tapping bolt etc. Welding a bolt and use of some kind of puller.

Grateful for any ideas on this.

Hi,

Am trying to change the rudder lip seals on my 13year old HR39.

I am having a big problem removing the Shaft Key ( Woodruff Key)

There is no gap between the end of the key and the slot in the rudder stock so I cannot get a good purchase to lever it out.

Have tried heating it up without success.

I have tried drilling and tapping a bolt radially into the key to try and prize the key out of the slot but not sure if I have gone deep enough. I do not want to damage the shaft.

Any suggestions very welcome.

Regards,

Steve.

 

[RichardS]

Hi,

Am trying to change the rudder lip seals on my 13year old HR39.

I am having a big problem removing the Shaft Key ( Woodruff Key)

There is no gap between the end of the key and the slot in the rudder stock so I cannot get a good purchase to lever it out.

Have tried heating it up without success.

I have tried drilling and tapping a bolt radially into the key to try and prize the key out of the slot but not sure if I have gone deep enough. I do not want to damage the shaft.

Any suggestions very welcome.

Regards,

Steve.

I'm guessing that it's not a "half-moon" key as they as usually easy to remove as you can get some purchase under the overhanging lip at each end?

To be honest, I've never had one that didn't come out using a sharp rap with a hammer, either against the back of the shaft of against the side of the key. Heat will definitely help even if it's just boiling water.

Richard

 

[rotrax]

I have a genuine 5 inch vise grip with a large nut welded to the adjusting screw. This allows me to fix it to my small slide hammer. By clipping the vise grip to something fixed into a blind hole - I used it first on motorcycle cam spindles - gentle use of the slide hammer invariably pulls them out.

I always used a protector sleeve and heat if required.

Old bushes, split lengthways made good protector sleeves - not that they would be required on a key.

Other mole type grips ARE available, but none work as good, or last as long as genuine Vise Grips in pro use.

Something similar might help.

Good Luck.

 

[clausewitz]

I drilled a hole, made threads and turned the key out with a M8 bolt. When making threads, you need to be careful that they only come in key, not in rudder shaft. In no other way would it have been possible to get it out. At the Hallberg-Rassy's shipyard, they had been forced the key to a keyhole.

 

[Daydream believer]

I have seen some woodruff keys held in place with a grub screw. Check there is not one covered with dried grease at the mid point of the key

 

[RichardS]

I drilled a hole, made threads and turned the key out with a M8 bolt. When making threads, you need to be careful that they only come in key, not in rudder shaft. In no other way would it have been possible to get it out. At the Hallberg-Rassy's shipyard, they had been forced the key to a keyhole.

It's a good solution to a tricky problem. I'm just wondering why you decided to use something as large as M8 since you presumably had to drill some way into the rudder stock even though you did not tap it?

Richard

 

[Daydream believer]

You cannot normally successfully tap to the base of the key. A solution would be to drill a 5.2 diam hole so it goes through thekey & stops at the shaft. Then tap 6mm most of the way through the key.Use a second tap then a main tap to get thread as far as possible. Then insert a 4mm ball bearing then tighten a 6mm bolt down onto the ball. That will enable the bolt to apply pressure against the shaft without the bolt having to go right to the shaft where one will not be able to tap. If you tap too far you will only tighten the bolt into the shaft & not force the key upwards.
A 6mm metric bolt wit 1 mm pitch normally has a 5 mm hole but one does not need massive thread engagement so a 5.2 mm hole will make tapping into a hard steel key easier