key way repair

Matt Thomas · Jun 10, 2015

Any of you have experience repairing a woodruff key slot with JB Weld or a similar product? My old '38 AC B has had some shade tree engineering performed on the crankshaft pulley and the key slot on the crank is now wallowed out pretty badly.

Steve@Advance · Jun 10, 2015

That's not a good situation. How does the crank pulley fit? Likely both the OD of the crank and the ID of the pulley are wallowed out from running loose.

Not much you can do for the crank short of replacing it or having it built up.

Could find another pulley.

JB weld couldn't hurt, but probably won't help much. I would probably clean everything, really clean with spray carb cleaner and scotch brite, then put it together with red locktite on the shaft, inside the pulley, on the bolt, go with a new grade 8 bolt and washer if there is any looseness in the thread. Tighten it as tight as you dare, hope for the best, keep an eye on it.

Mike(NEOhio) · Jun 11, 2015

I think JB could work. Clean the surfaces real good. Get a new key, rub some paraffin on the sides to keep the JB from sticking to it. Clamp it into the bottom of the keyseat and pack the sides with JB. When it hardens, pull the key out and finish the diameter.

Better way if you have a machine shop nearby. Recut the keyseat for a thicker key and step-grind the new key to fit the pulley.

Dave H (MI) · Jun 11, 2015

I did something a couple years back on my 300U when the PTO would not disengage. Thought it was the bands but turns out it was the keyway in the handle had too much slop because the tractor side keyway was wallered out. I cleaned up the enlarged slot then took several larger keys and found one that fit in the enlarged slot without moving. I marked the key and took it up to the local machine shop and had a fella machine the exposed half so that it fit in the slot on the handle side. So I had a key with two different dimensions. This worked the first time I tried it. No more slop and the PTO bands were now adjustable to where they could shut off. I don't know if this will work for you on a crankshaft. Just a thought.

Stephen Newell · Jun 11, 2015

I have used a dremel tool with a metal cutting blade and made the slot bigger and replaced the key and pulley with a larger one. On another that didn't have the key slot I used the same dremel tool and cut a slot for a half moon key. I don't know any reason you couldn't cut a slot on the opposite side.

key way repair

Matt Thomas

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Steve@Advance

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Mike(NEOhio)

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Dave H (MI)

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Stephen Newell

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