Review on 🔧 DEWALT Spring N078434 by Raymond Doe

Before you begin, search any YouTube video for how to replace a Dewalt hammer drill chuck spring. Cover the table with an old white towel. The small ball bearing is very easy to lose! None of the videos show where the ball bearing is in relation to the spring stem. If there is a position error, the cartridge will pick up the bit and hold it, but not let go! The tongue of the spring runs under the ball bearing. This means that the ball bearing is in the groove, but as far away from the collar as possible. You will need a set of very small flat head screwdrivers and 3 hands to reattach the small retaining ring. I used these from Revain: https://www.amazon.com/Choice-9-Piece-Precision-Screwdriver-Phillips/dp/B0747DYJJRA Alternatively, look for a tiny bushing or tube of the correct diameter to hold the retaining ring to attach shank and into the groove.