Electric Drill: Bad Vibration

Bearings will make a growling, humming or low moaning sound and will be accompanied by a vibration when they are going bad. To replace a bearing that has worn out, open the drill case by separating the screws holding it together. With the case open, you can now pull the shaft out that has the worn bearing. If you do not know which bearing has gone bad, you can check them by spinning them by hand, listening for an abnormal sound.

To replace a bearing, use a bearing separator to remove it. Once the separator is installed on the bearing, place the separator on top of a bench vice and open it enough so it does not make contact with anything but the separator. Then, tap on the shaft with a punch and a hammer until the bearing is free. To install a new bearing, place a socket on the race of the bearing to avoid damage and tap it in place with a hammer. You can also use a washer big enough too. Reinstall back on the drill housing and secure the case back together.

If you are experiencing a bad vibration, check the chuck for tightness to the drill. If it is loose, it can cause a bad vibration. Tighten if loose. Next, insert a drill bit in the chuck and tighten it – try to wobble it back and forth. If there is any movement, and the chuck is installed tightly on the drill, then change out the chuck.

To remove the chuck, insert the proper screwdriver into the chuck to remove the screw at the bottom (this is reversed thread). Once you’ve broken the tightness of the screw, continue to remove the screw. With the screw now removed, insert a big allen key into the chuck and tighten it down on the allen key. Lock the chuck in place in a bench vice, then insert a pipe over the allen key for leverage. Turn counter clockwise to loosen the chuck. A second method is to hit the allen key quickly with a hammer to loosen. You do not need a bench vice for this. Once loosened, continue to remove from the spindle. Install the new chuck by threading it on the spindle. Next, open the chuck and insert the allen wrench – tighten the chuck down on the allen wrench. Now, turn the allen wrench and hand-tighten the chuck. Remove the allen wrench and reinstall the screw, remembering it is reverse thread. Lastly, tighten the screw.

Worn, damaged or gears with missing teeth can cause a vibration in the drill. The gears are housed in the front, inside of the gear housing (on some models). Listen for a noise coming from the gear housing. To replace a worn, or broken, gear, remove the screws securing the gear housing cover to the front of the drill. Inspect the gears for damage.

To replace the gear, remove the shaft, or spindle, from the housing. Use a bearing separator, or puller, to remove the bearing. Remove the retaining ring, gear and keyway. Install the keyway on the shaft with the new gear and reinstall the retaining ring. Install the bearing with a socket placed on the bearing race to avoid damage to the bearing and tap in place with a hammer. Clean and re-grease the gears inside the housing.

Reinstall the gear housing cover and secure it tight. On other models, you will have to remove the screws securing the drill case together and separate the two halves to access the gears. Remove the shaft and gear assembly. Using a bearing separator, remove the bearing. When the separator is installed on the bearing, place it on top of a bench vice, opened enough where it will not make contact with anything but the separator. Now, tap the shaft with a punch and a hammer until the bearing is free. Depending on your model, there may be a retaining ring that you can remove to separate the gear from the shaft.

Then, install the new gear, ensuring the keyway is installed on the shaft first. Reinstall the retaining ring and wave washer. On other models, you would replace the gear and shaft assembly as one. Reinstall the bearings on the shaft by placing the bearing on top of the shaft, with a socket on the race, tapping it in place with a hammer. Reinstall the shaft in the drill and close the case back together. Lastly, tighten the screws.

A spindle can become worn, or bent, from too much pressure being applied. This can cause a vibration in the drill. To replace the spindle, start by removing the chuck. Insert the proper screwdriver in the chuck to remove the screw at the bottom. This is reverse thread. Take a big allen key and insert it in the chuck – tighten the chuck down on the allen key. The chuck is reverse thread. Hit the allen key quickly with a hammer to break it free from the spindle.

Depending on your model, remove either the front gear cover or separate the two halves of the drill case. Now, remove the spindle and separate the bearing from the spindle with a bearing separator or bearing puller. Remove the retaining ring, gear and keyway and reinstall them on the new spindle. Then, install the bearing on the new spindle by placing a socket on the race of the bearing to avoid damaging the bearing. Tap into place with a hammer. Reinstall on the drill and fasten the gear housing back on the drill or, on other models, rejoin the two halves of the case back together. Tighten all fasteners.

Reinstall the drill chuck by threading it on the spindle. Next, open the chuck and insert the allen wrench and clamp the chuck down on the allen wrench, then turn the allen wrench to hand tighten the chuck. Finally, reinstall the screw tight, remember the screw tight (remembering it is reverse thread).