Damaged chuck I need to replace the chuck on makita hp1620F hammer drill. How do I take the chuck off?

as long as the chuck is used for a hammer drill and the thread size is exact yes it will. I believe the thread is 1/2-20 and also make sure the chuck has a hole in the center for the reversing screw to keep it from loosening up. Let me know if you need more assistance. The thread size is usually stamped on the side of the chuck. Makita sometimes used a metric thread.

I answered that question already on another post, but if you need to know how to remove the chuck I have detailed instructions in the TIP SECTION on how to do this. Let me know if you need more help

Open the chuck up fully, and in the bottom there is a reverse threaded lock screw that needs to be removed. (drill it out if you have to, it can be really hard to retrieve). Insert an allen key into the jaws of the chuck and hit the handle with a hammer to turn the hole chuck anti clockwise, firmly and quickly. Replacement is reverse but not so dramatic. Sometimes the chuck is damaged in such a way that it will not grip an (large) allen key sufficiently. You can then peel of all plastic parts of the chuck to expose the core. From here you can weld a metal pice to the chuck in place of an allen key. Take care not to damage the threaded axle from the gear.

good luck

Sounds like the chuck is worn, happens frequently when used often. Here's the link to Makita, their contact info should get you some answers as to what part number is needed as well as the closest location to you for service if required. Hope this helps.

http://www.makita.com/en-us/Modules/Tools/ToolDetails.aspx?ID=316372

The chuck may have a left hand screw insde and at bottom of chuck, some chucks scew on and the screw holds it in place, may have to put an allen wrench in chuck and hit the wrench with hammer one way or the other to losen it.

Look at eReplacementParts.com and the parts diagrams

Check out the split drawing on this page.
If your makita does not have any outside accessible brush caps, you need to dismantle it.
lay it on the side, where the side with the screws securing the to halves together is facing up.
Remove all screws (some may be hidden under labels etc.) Gently pry the halves apart, locate the brushes disconnect their leads if any, and remove. Install new brushes and make sure the move freely, and that they are springloaded when in place. Gently rotate the rotor to ensure everything is ok . Reassemble and test drill. If the brushes leaves long streaks of noticeably large sparks, something has gone wrong or the rotor was damaged in the first place, causing excessive wear.

Remove the screw inside (clockwise)
mount a big Allen key in the chuck ,shortest part inside the chuck,
hurt the key with a hammer to make tre drill move counterclockwiseto unblock it

look inside the chuck for a screw. it will be a left handed screw.once you get the screw out put the chuck in a vice . you will need to squeeze it very tight. then put the drill in reverse and pull the trigger.if i wont come off you will need to hit the chuck with a hammer while you are holding the trigger.

open the chuck all the way, insde there may be a screw in the bottom it's lefthand thread turn it clockwise to remove, the chuck is also threaded, right hand thread. close the jaws on the short end of an allen wrench and strike the long end with a hammer to break it free