Like any other component, the drill chuck wears over time or becomes filled with dust or rust that causes it to seize. Whether you want to clean it or replace it, you must first disassemble it from the drill. If you want to modify it by hand, follow the instructions for the keyless chuck, or read the second section, if your model requires adjustment with a key.
Steps
Method 1 of 3: Change a Keyless Chuck with an Allen Wrench
Step 1. Remove the screw in the center of the spindle
Loosen the jaws by bringing them to the maximum opening. In almost all of these tools there is a screw at the base to fix the element to the body of the drill. Insert a suitable size screwdriver here and turn it clockwise to remove the reverse thread screw. The screw is usually coated with a thread locking fluid, so you need to exert some force.
- Skip this step if your model does not have a screw.
- If the screw is fully locked, follow the steps below to loosen it; remove it and repeat the same process.
Step 2. Insert the Allen key into the chuck
Choose the largest you can fit in so that it fits snugly.
Step 3. Set the transmission to a minimum
By doing this, reduce the resistance between the gears as much as possible.
Step 4. Tap the Allen key with a mallet
Lay the drill down so that the Allen key is horizontal and protrudes from the edge of the work table. Strike the end of the key firmly, in a top-down motion using a rubber or wooden mallet. Most spindles have a standard thread, so by hitting the Allen screw counterclockwise you should be able to loosen it. If you want to be sure, contact the manufacturer of the drill and ask if your model has a standard or reverse thread on the motor shaft.
If you hit the Allen wrench too hard or at the wrong angle, you could break or bend the outer shell of the drill. Start with light pressure and increase the power as needed. This is especially important if you are trying to loosen a stuck screw
Step 5. Remove the chuck by hand
When it has been partially unscrewed from the drill body, you can continue by hand.
Step 6. Apply new locking fluid to the screw (recommended)
When you are ready to assemble the replacement part, put a drop of thread locker on the end of the screw. Rub it between your fingers to evenly sprinkle the liquid.
If the keyless chuck does not have the screw, you will need to use the liquid on the thread of the drill body that the chuck engages on
Step 7. Reassemble the spindle
You can use the same tools to install a spare or properly cleaned old spindle:
- Slide the base of the spindle into the motor shaft.
- Open the jaws.
- Insert the Allen key and tighten the jaws by hand.
- Insert and tighten the screw by turning it counterclockwise.
Method 2 of 3: Change a Keyless Chuck with an Electric Screwdriver
Step 1. Insert a hex socket in the center of the spindle
If you were unable to loosen the workpiece with the previous method, an electric screwdriver can exert more force. Insert a hex socket in the center of the jaws and tighten the jaws to lock it.
- If there is a screw in the center of the spindle, you must first remove it by turning it clockwise.
- This method carries a greater risk of causing damage to the drill or the chuck itself.
Step 2. Set the drill to neutral
Put the transmission in neutral position, neither forward nor backward.
Step 3. Rotate the compass counterclockwise with the electric screwdriver
Insert the tool into the compass, set the reverse rotation and start it in short pulses to loosen the chuck from the drill.
Step 4. Unscrew it by hand
At this point, you are able to continue the work by hand.
Method 3 of 3: Change a Tapered Mandrel
Step 1. Measure the diameter of the motor shaft
Keyed chucks are not usually screwed onto the drill, but have a tapered end that mates onto the motor shaft. Observe the space between the base of the spindle and the body of the drill, you should see the shaft: measure its diameter.
Step 2. Buy a wedge to remove the mandrel
It is an inexpensive wedge-shaped tool with two arms. Choose one whose space between the arms is larger than the diameter of the crankshaft, but very similar in size.
If you are in a hurry, read the method described at the end of this section
Step 3. Insert the wedge between the drill and the chuck
Make sure that the crankshaft is between the two arms.
Step 4. Hit the wedge with a hammer
Keep hitting it until the chuck comes off the drill.
Step 5. Install the replacement part
Clean and degrease the conical portions of the motor shaft and spindle. Engage the latter on the shaft and open the jaws fully. Place a small piece of wood over the tip of the spindle to protect it, then hit it with a mallet to secure it in place.
Step 6. Remove all crankshaft
If you don't feel like going to the hardware store to buy the wedge, you can take the whole shaft apart. This method only works for spindles with the center portion open, as it allows you access to the components below. Here's how to proceed:
- Fully open the jaws.
- Place the spindle in a bench vise with the motor shaft dangling down.
- Insert a metal awl in the center of the opening.
- Hit the awl with the hammer until the crankshaft comes off the drill.
