G0752 Chuck stuck good and hard!

P

Perplexed

Registered
Registered
Joined
Aug 6, 2021
Messages
5
Hi all, this will be my first post since I joined, though I’ve frequented the site over the past few years. I could always find the info I needed, but not this time, so maybe you folks can help…

I have a G0752Z lathe, and it came from the factory with the 3-jaw chuck installed. I’ve been using this chuck from the beginning, and it’s now about two years later that I decided to try the 4-jaw chuck. This is where I ran into a major problem.

Simply put, the 3-jaw chuck is stuck. As in, will not budge an iota. I removed the safety collars per the instructions, and inserted the two chuck keys, and tried to spin the chuck off in a counter-clockwise direction. Nothing. Nada. So I sprayed some penetrating oil in the seam between the chuck and the spindle collar, and let it sit overnight. No luck. I found a length of drill rod blank that just fit into the hole on the spindle collar (where the small chuck key would go) and I put a thick layer of leather on the ways, then braced the drill rod blank against it so I could try again with more leverage. Nothing. I even tapped the large chuck key with a soft-headed mallet, with no success.

Before screwing up anything, I contacted Grizzly tech support. Their answer was basically what’s been posted on YouTube - use a strap wrench on the pulley on the left while using a large adjustable wrench on one of the jaws in the chuck. That didn’t work since the strap on the wrench kept slipping under force, so I put a layer of sandpaper underneath for added traction. That still didn’t work.

What I think I’ll need to do is immobilize the spindle completely so I can really wrench down on the chuck with both hands. Aside of taking all the pulleys, gears, spacers, keys, etc. off the spindle so I can remove the spindle with the chuck still attached, and put the spindle in a padded vise - is there anything else I can try to get the chuck off the spindle??

Thanks in advance!
 
Try removing the jaws and spray some penetrant at the thread seam inside the chuck.
Spray it every half hour for a 2-3 hours.
Try undoing the chuck using a strap wrench on the chuck od, and a long pin punch in the hole behind the register.
If it still doesn't come loose, fit a tommy bar in where the chuck key goes and give it a sharp rap with a decent hammer a number of times.
Protect your ways.
Clean and grease or oil the spindle threads as part of your maintenance.
Let us know how you go.
 
You may need to use some heat from a propane torch around the chuck/ spindle interface. Be aggressive but cautious with the heat. Protect the paint.
A high wattage light bulb put close to the chuck might even be a better choice, and safer.
Soak with penetrating solvent (liquid wrench) for several days beforehand. Maybe even a week. Be patient, it will come off.

Use the strap wrench, perhaps with an additional thick piece of rubber around the pulley to prevent damage. One approach I have used is to put a large hose clamp around the part with a leather belt as a protector. Then you can grab the clamp with large pliers or strap wrench, wedged against the adjustment screw on the clamp.
Put a long piece of hardwood in the chuck jaws and whack it with a piece of 2x4. Protect the ways.
Grizzly is good about spare parts if you do mangle the pulley, it just may take time to get one.
-Mark
 
Last edited:
Perplexed said:
Hi all, this will be my first post since I joined, though I’ve frequented the site over the past few years. I could always find the info I needed, but not this time, so maybe you folks can help…

I have a G0752Z lathe, and it came from the factory with the 3-jaw chuck installed. I’ve been using this chuck from the beginning, and it’s now about two years later that I decided to try the 4-jaw chuck. This is where I ran into a major problem.

Simply put, the 3-jaw chuck is stuck. As in, will not budge an iota. I removed the safety collars per the instructions, and inserted the two chuck keys, and tried to spin the chuck off in a counter-clockwise direction. Nothing. Nada. So I sprayed some penetrating oil in the seam between the chuck and the spindle collar, and let it sit overnight. No luck. I found a length of drill rod blank that just fit into the hole on the spindle collar (where the small chuck key would go) and I put a thick layer of leather on the ways, then braced the drill rod blank against it so I could try again with more leverage. Nothing. I even tapped the large chuck key with a soft-headed mallet, with no success.

Before screwing up anything, I contacted Grizzly tech support. Their answer was basically what’s been posted on YouTube - use a strap wrench on the pulley on the left while using a large adjustable wrench on one of the jaws in the chuck. That didn’t work since the strap on the wrench kept slipping under force, so I put a layer of sandpaper underneath for added traction. That still didn’t work.

What I think I’ll need to do is immobilize the spindle completely so I can really wrench down on the chuck with both hands. Aside of taking all the pulleys, gears, spacers, keys, etc. off the spindle so I can remove the spindle with the chuck still attached, and put the spindle in a padded vise - is there anything else I can try to get the chuck off the spindle??

Thanks in advance!
Click to expand...
OK, I gather that your lathe has a screw on spindle. I would try putting a large Crescent wrench snug on one of the chuck jaws and then use a hammer to jar it loose. Have something substantial clamped solidly in the jaws. Have the spindle disengaged from the drive gears to keep them from being damaged. Don't whack it too hard or you might damage the chuck. Multiple smaller whacks are safer and usually eventually work it loose with some patience... A restraint made of belting or a v-belt wrapped around the spindle can help to keep the spindle mostly stationary.
 
1) Lock your spindle.
2) Mount some kind of steel bar in the jaws horizontally (you won't operate your lathe).
3) With the bar sticking out, hang weights from the bar - as much as it will hold.
4) Walk away (however, protect the ways from a bar coming down).

Overnight, your chuck should break loose.
 
This is a common problem with the G752Z. They include screwdrivers, a little oil bottle and cheap metric wrenches, but not the spanner needed to loosen the chuck. I ended up making a custom wrench from some A36 with a pressed in tool steel pin. You can make something like this using a metal bandsaw, a drill press, and some hand filing. I used a mill and a rotary table to get the inside curvature exact, but that's not really necessary. You'll use it over and over, so might as well do it now. The pin needs to sit at 90 degrees, or a tad more, from the handle.

IMG_3640.JPG
 
Last edited:
I take it that the spindle is NOT threaded?
 
I used to have a lot of trouble getting mine off too when I first got my lathe. Simply because the thread was poorly machined. I eventually took my spindle out and remachined it so it was actually concentric and of a full form.
Its size was actually reduced by around 030 thou, but chucks fit on much better and come off easier now.
May pay to check that spindle thread for size and geometric error.
 
I have a G0602 which is same hardware. I tend to tighten my chuck securely. I made a pin spanner rather than using a tommy bar. A 5/8" or 17mm open end wrench on the chuck jaw with the spanner on the spindle will break the chuck free.
www.hobby-machinist.com

Just One More

The Grizzly G0602 has three radial holes in the spindle for the purpose of securing the spindle when installing or removing a chuck.According to the user manual, you are supposed to use the second chuck key as a tommy bar with those holes. Well the chuck key didn't fit but no problem, I made a...
www.hobby-machinist.com www.hobby-machinist.com
 
You must log in or register to reply here.
Back
Top