10K Model A gearbox suddenly started making a clunking sound

it could be that a chip has gotten caught between the gear teeth. With the lathe off, and the reversing gears this engaged, take a mirror and a flashlight and look closely at the gear teeth. Clean as necessary. If that doesn't work, you'll need to take the gear box off and inspect it closely. At that point a good general cleaning will not hurt it. Make sure you lubricate everything before you go back together with it. also check and clean all the other change gears and reversing gears, chips can get caught in those gears as well.

stay safe and have fun.
Joe.

promacjoe said:

it could be that a chip has gotten caught between the gear teeth. With the lathe off, and the reversing gears this engaged, take a mirror and a flashlight and look closely at the gear teeth. Clean as necessary. If that doesn't work, you'll need to take the gear box off and inspect it closely. At that point a good general cleaning will not hurt it. Make sure you lubricate everything before you go back together with it. also check and clean all the other change gears and reversing gears, chips can get caught in those gears as well.

stay safe and have fun.
Joe.

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Thank you for your reply Joe.
I will use a mirror and flashlight to look for chips.
If I have to remove the gear box, can you tell me what is involved?
Or is there some place that I could download the instructions?
pg

it's pretty easy to remove the gearbox on a 9 or a 10K lathe. First of all, is it a bench or underneath drive lathe. If it is an underneath drive, does it have a chip pan that extends under the gears. If so use these procedures.

1: remove the change gears from the Banjo.

2: Loosen and rotate the banjo until it touches the bench/chip pan and lock it in that position.

3: place a block of wood under the tumblers and lower the tumblers until they rest upon the blocks of wood and lock them in place. This will support the gearbox while you are removing the three screws.

4: loosen the three screws that support the gearbox And remove them. Make sure the gearbox is well supported as you loosen them. You don't want to bend the lead screw.
Note: if you have problems accessing the three screws, It may be possible to loosen the headstock on the bed and slide it to the right. The screws on my lathe were easily accessed, but I have heard that some have had problems with it.

5: carefully slide the gearbox and lead screw out to the left of the lathe. Again be careful not to bend the lead screw.

at this point you can set the gearbox/lead screw on the bench or even the floor if it is Clean. A piece of plastic tarp or something to catch any grease and oil that you might clean out of the gearbox is preferable.

Use the same procedures in reverse to reinstall the gearbox.
Note: make sure the leads Screw Lines up with the corresponding keyway in the apron.
going back can be tricky, you may need to remove the apron To align the key properly.

If you do not have a Bench lathe or chip pan, or the banjo will not Rest on anything you will not have good support for the gearbox. If that is the case you may need someone to help you. These things can be awkward and kind of heavy so be careful.

stay safe and have fun.
Joe.

I'm glad you found the problem. Those chips get everywhere. Just a note when setting up gears, a page out of a old phonebook works great To set the clearance between the gears. It's pretty close to the right thickness. and we all have phonebooks that we don't need anymore.

Stay safe and have fun.
Joe.

glad you found your problem and it was nothing serious.

for future reference, a peculiarity of the underdrive 9`s and 10K`s, if you ever have to remove the gearbox you will find that the far right of the three screws is not removable due to the headstock sitting over the edge of the screw head.
on my old 10K i side stepped this by replacing the 3 screws with socket head screws, the headstock will still be on top of the screw but you will be able to get an allen wrench on it - remove the other 2 screws first, and then you can use the far right screw to gently "lower" the gearbox down to your support( just like Joe suggests)

the screw will stay captured by the headstock,and remain in it`s hole, but it will make it much easier to take the gearbox off for the occasional cleaning/inspection without having to scoot the headstock( that right side headstock clamp can be a bear to get to)

also good to crank the carriage all the way to the far right, and looosen the 2 apron screws and leadscrew support screws to avoid puttig the leadscrew in a bind.

not sure what it is about those 10K`s but every one i have had an opportunity to run has been a real sweetheart.
your being the variable speed model just makes it that much sweeter.
if one ever came up around me, i doubt i could resist, even though i certainly don`t need one.
i even liked the 6K collets direct in the headstock - good stuff.

piniongear said:

I used a single sheet of bond paper, tearing off a strip to put between the gears. The single strip seemed to work well.

So I then took two strips of that same bond paper and placed those between the gears.
The result was the gears no longer fully engaged, and in fact would skip teeth when turned by hand.
So I went back to a single strip of bond paper.

Now I have to agree with you to use a strip of paper from the phone book. If 2 sheets of bond make it that loose, then I am sure 1 sheet of bond is too thick as well.
So I will give it another go with the phone book. Thanks!
pg

Click to expand...

Just wanted to know how the phone book paper work for you, And if your gears are quiet now.

Stay safe and have fun.
Joe