How to onlock the keyless chuck of my cordless dc988ka drill it was lock to open position

The chuck is held onto the shaft with a Philips screw. Open the chuck, insert the screwdriver and turn CLOCKWISE to loosen the screw. The chuck will still be connected to the outer thread on the shaft. Slide the drill direction slider to the middle position to lock the motor. Put an Allen key in and close the chuck around it. You will now be able to use that to twist the chuck off.

If your drill has the original keyless chuck on it, there are two plastic rings on the chuck. The outer ring should tighten and loosen by hand enough to hold the bit(s). The inner ring is to hold on to if the chuck gets overtightened. Chucks do wear and get corroded over time and can get locked in position. If you can't get it loose by hand, channel lock pliers can help. If the chuck is that bad you may need to replace it.

I have the same problem. It got progressively worse over time. The chuck did not want to tighten all the way at times and then got stuck open. There is a screw in the center to hold the chuck on. It is a left hand thread and I believe it loosened and the jaws became jammed on the loose screw. I tapped on the screw using a screwdriver and was able to tighten it a bit thus allowing the jaws to free. I removed the screw, put some thread locker on the threads and reassembled it. Seems fine now

if it is a keyless chuck soak the inside of the chuck with oil. charge the battery so you have max power. put a cloth around the chuck and use a pair of channel locks to hold the chuck and put the drill in reverse. good luck

Look at the three jaws in the chuck,if on is further out than the others the you need to tap ti back into place with a small punch and a hammer.If this does not work then you need to replace the chuck,remove the screw at the bottom of the chuck[where you put the bit],then you will need to to clamp vise grip on the chuck and with it pointed away from you hit the vise grips with a hammer with a sharp blow downward and it should come off.Hope this helps.

This drill has a keyless chuck. Put your bit in the chuck and hold the collar of the chuck while pressing the trigger in the forward position. To undo the chuck do this in reverse. You can also hand tighten the keyless chuck if you prefer. I have a 1/4' adapter that I keep in my drill so I can change bits quickly.

if chuck is wide open ,look down inside there should be an allen screw or bolt at the bottom of the chuck it should undo anti clocwise and the chuck comes off

Can'y find anything with the model number furnished, but generally to replace a chuck on a cordless you first have to remove the chuck screw LH threads and then shift the tool to the LOW position and the clutch to the drill only. Find a bent handle allen wrench about the same size as the chuck capacity and lock the smaller end in the jaws. Put the chuck on a work bench or block of wood with the handle at about a 30 degree angle so that you will be striking the wrench in the counter clockwise position, you might have to hit it a couple time but it will come off

What you can try is some WD 40 spray into the chuck and then find a GOOD pair of gloves or a rag and hold the collar of the chuck either by hand or use the rag and a pair of channel locks to protect it and then use the tool motor slowly and see if that doesn't release it

In continuation after removing the chuck screw which is left hand thread shift the drill to LOW and use a bent handle allen wrench approx the size of the chuck lock it in the jaws. Turn clutch setting to the drill only position and using a hammer strike the hex key. The chuck has standard threads. To reassemble just reverse this