How do i remove a dewalt chuck in the DC 988 drill ?

https://www.youtube.com/watch?v=pNDgV_6k12E
Reverse and Forward Mode: Try putting the drill in reverse mode and hit the trigger, then forward mode. If that doesn't work, tap the tip on the driveway but don't slam it. It should release .

Use a Wrench: First, make sure that the chuck is in the locked position. Next, use an allen wrench to loosen the set screw on the side of the chuck. Finally, unscrew the drill bit from the chuck .

Remove Chuck Collar: Use a wrench or pliers to loosen the chuck collar and remove it from the chuck. Then, use a screwdriver or other tool to remove the chuck jaws and any other components that may be blocking access to the stuck drill bit. Once these components are removed, you should be able to access the drill bit and remove it from the chuck .

Open the chuck jaws and look down inside the chuck. You will see a screw head that is holding the chuck to the drill. Once you remove the screw, the chuck should pull off easily.

My solution when the other mentioned ideas didn't work was this: I removed the 7 Torx #20 screws ( a common screw driver will work as well) and removed the housing half to expose the shaft. The chuck shaft bearings and gear lifts out as one assembly. Directly behind the chuck there is a half inch section of shaft exposed. I mounted a vise grip on the shaft (won't hurt it) and clamped the affair in a bench vise. With a 5/16" allen wrench mounted in the chuck and using a mallet I spun the chuck off with a solid smack counter clockwise . Very simple and easy .

Inside the chuck, if it is wide open, you should see a screw with a T20 head It is reverse thread so turn to the right to loosen. If it is too tight, clamp gently with the chuck facing up and let some WD-40 soak in for a while.

If the drill is not too old, I would take it to your nearest factory dewalt repair shop. they have a good warranty on their items. If it is older you probably need to replace the chuck itself. You need to remove the plastic to get the chuck open and then there is a screw down inside the chuck that needs removed. The chuck should come right off and just reverse the process to install the new one.

Look at eReplacementParts.com and the parts diagrams.

The dc925 and the current model dcd950 along with several other models of Dewalt 's line of cordless hammer drills DO NOT have a screw inside removal requires a CHUCK REMOVAL FIXTURE part #
233804-40 also you can't use a generic replacement chuck. As of 2/2/2010 the prices on the Dewaltservicenet web site are $72.74 for
the tool and $69.70 for the chuck, part # 330075-90.

first shift the drill to the drill only position and the gear selector to the low position, remove the chuck retaining screw LH thread, find a bent handle allen wrench about the chuck capacity and lock in the jaws of the chuck, put the chuck on a block of wood at about a 30 degree angle to hit the long portion counter clockwise and strike it with a hammer, it might take a couple hits but it will come off. I misread the header last time.

Inside the chuck is a left-handed screw. torx (star) T20. When you get it out, take an allen wrench and (if you can tighten it up at all, tighten the **** out of it). If not, find an allen wrench, a tiny bit smaller than the space allowed. Now, get a nice big hammer. The chuck is right handed thread. And knock it, spinning the chuck off the spindle. May take a few whacks. Use the edge of a workbench to keep it stationery if need be. Lemme know. Please rate me

If you are in America/Canada go to dewalt service net http://www.dewaltservicenet.com/servicenet_home.aspx?AspxAutoDetectCookieSupport=1. make sure you check the type number as there are some variations across the model range. You should find the type number either just after the model code or on the top right of the rating plate.
If in U.K. then go to https://service.toolcommerce.com/products/HomePage.aspx?BrandId=2&language=en-GB&country=GB.
You should be able to ID the part and find a dealer from these sites.