Help! How to get the square peg in the round hole??

[Rohan]

This is about my anchor windlass, but actually this is problem for any engineer.

Short version: I need to replace my sealed bearing on my Simpson Lawrence Sprint Atlantic windlass, but I have no idea how to get it on.

Full background: I took apart my windlass and found that my wiper seal was no longer sealing and there was a ton of rust underneath. So I ordered a maintenance kit which included some spare parts.

The problem is on the gipsy/gypsy drum. Look at the attached photo. This is basically the drive shaft that runs from the motor to spin the drum to pull up the anchor.

A - is the rusted remnant of what was left of the old sealed bearing around the shaft. It's really stuck on there, but I can chisel it off. That's not my real problem. I pointed it out to show the position.

B - is a brand new sealed bearing. It would be just the right size to fit around the shaft, if it weren't for C below.

C - is a metal strip that sticks out of the shaft. Sometimes it's called a "drive key". But whatever it is, it makes it impossible to me to put a new sealed bearing on from the right end. And the shaft is way too wide on the left end.

There is an edge around this drive key so it looks like it was added on later. But it's on really solid. It doesn't collapse, and it doesn't come off. Is it glued on? I don't know. But there's no way to get it off without doing serious damage. So how the heck do I get the sealed bearing on?

If you are curious you can also look at a full schematic by clicking on the picture here. This shaft is part #95, and the sealed bearing is part #17.

Another option would be to buy a new gypsy shaft. But I have no idea where. The company was bought out by Lewmar and this model isn't made anymore. And I can't find this item available anywhere. Plus, even if I found another one, it would probably have this same problem with the drive key. And overall the windlass is shiny and it great shape except for the parts I am replacing.

So what would be your next step?

[Bycrick]

If I read the diagram correctly, and I don’t claim to be a great mechanic, the key is shown as part #21. So it will come out eventually. They’re supposed to be tight. I’ve seen some people, not me, put them in with Loctite. Since I’ve never NOT been able to get a key out with just some tapping and maybe a set of vice grips, I’m hesitant to make remote suggestions.

[dfelsent]

I’ll bet that drive key is just a tight fit in a slot in the shaft.
They can be easy to get out , or tough. You don’t want to damage the shaft removing the key.
Often one end of the keyway is tapered / sloped and you can tap the key out in that direction.
But don’t dent the key or shaft. I’ve used a wood block with a hammer in a similar situation.
Or just about any machine shop will get it out for you.

And I’m sure there are others here who will have more experience removing keys.

[chris95040]

Do you own vice grips?

[Jammer]

What you do is remove the key. You can try penetrating oil. You can try gently heating the shaft, no more than necessary, a dull deep red should be plenty and can be achieved with a propane torch. Typically the slot goes all the way to the end of the shaft, if that's the case, you can drive it in that direction with a punch.

You can try cooling the key to make it shrink slightly, using freeze spray, dry ice, or liquid nitrogen.

You can weld a piece of scrap to the key, and use that to get enough of a grip to pull it out.


It doesn't matter much if you damage the key because you can make a new one. Any auto parts store will sell you key stock in standard sizes, which you can cut to length. If it's an oddball size you may have to order a piece. You can round the ends with a grinder or file if you want an exact match.

A good machine shop can make you a new shaft, if that should become necessary. You will probably find some pitting under the old bearing, which would be a reason to replace the shaft anyway, depending how bad it is and how picky you are. The last time I had a shaft made by a machine shop it was between $100 and $200 as I recall, and similar in complexity to what you have there.


I used to farm and replaced dozens of bearings on keyed shafts.


Usually getting the old bearing race off is the trickiest part. They are hardened. You may find that a chisel doesn't do much. I almost always use a cutting torch. You have to be careful not to cut into the shaft, and it's a delicate operation.

[Bill Seal]

Try a brass or aluminum drift and drive it out. A steel one might screw up the shaft.

[Spot]

Do people still chill the shaft in a freezer and mildly heat the bearing before reinstalling in this situation?

[Sailmonkey]

Originally Posted by Spot

Do people still chill the shaft in a freezer and mildly heat the bearing before reinstalling in this situation?

All the time. Bearing in hot oil and shaft in the deep freeze.

[Rohan]

Thanks for the ideas. Maybe I should take it to a machinist or metalworker in my area. If anyone knows someone around the DC metro area/Chesapeake/Northern Virginia I'm all ears. I have a heat gun, freezer, and vice grips, but no heavier equipment than that.

[Cpt Mark]

Do not use vice grips. Just tap it out.

[endeavour55]

small cold chisel and a small ball-pin hammer and tap tap tap rust buster will help. have patients. put the chisel on the end like you are going to tape it out of the slot. works all the time.

[Shrew]

I'll admit I don't have a Simpson Lawrence windlass, however when I rebuilt my windlass, I do recall it being tricky to reassemble everything while holding the key in the keyway. I can understand why someone would decide to locktight (or worse) the key into the keyway, however that key SHOULD be able to be removed.

When I used to replace the roller bearings on my dirtbikes, I used to toss the bearings into the freezer for a day. I couldn't stick the entire wheel into the freezer and didn't want to de-spoke the hub, so only the bearings would get frozen in that case.

I would think that heating either the shaft or the bearings would cause the metal to expand, making the fit tighter, not looser. It would seem that freezing both would cause both to contract slightly and make for an easier fit. Just my humble opinion. Someone might point out the flaw in my logic.

[Sailmonkey]

Originally Posted by Shrew

I would think that heating either the shaft or the bearings would cause the metal to expand, making the fit tighter, not looser. It would seem that freezing both would cause both to contract slightly and make for an easier fit. Just my humble opinion. Someone might point out the flaw in my logic.

Heating a bearing that goes over a shaft increases it’s ID as well as it’s OD.

So you’d never heat a bearing to interference fit it in a socket, but you do to fit it over a shaft.

[Cadence]

Originally Posted by Rohan

Thanks for the ideas. Maybe I should take it to a machinist or metalworker in my area. If anyone knows someone around the DC metro area/Chesapeake/Northern Virginia I'm all ears. I have a heat gun, freezer, and vice grips, but no heavier equipment than that.

Go to a machine shop. Probably cost little or nothing and might save damage.
Throw the vise grips away they will probably mar the key. A brass drift pin or an oak block might drive it out.

[jack630]

Take it to a machine shop. They know how to press a bearing on. They do it all the time. They might stick the shaft on a lathe and clean it up.