I love this tool. Very powerful! For those who are having issues with bits falling out, I'm here with the solution. The hex portion of the bit needs to be long enough to seat properly in the driver head. Because of the 1/2 driver portion of the tool, hex bits need to extend more deeply than other drivers. I have included pictures below that illustrate this. If you have an investment in bits you want to use, then I suggest an adaptor until you aquire bits that fit natively. Again, see the pictures below. I show one on the far right of image 1. Image 2 shows how deep the bit needs to seat to lock vs. another brand of driver.

I've had this GDX-1800 for a few years now and it typically travels with me in the vehicle and has handled every task I've put her up to, including moderate repairs on my vehicle and others, drilling/driving fasteners, etc. Admittedly I have not tried using her for heavy tasks; I understand and respect the limitations of this tool and have my expectations set accordingly. I'm a huge fan of the engineering behind this tool, it is an average driver and average impact wrench but combined is a neat idea. I owned a GDX-1600 before and the 1800 is a big improvement; eventually I'm sure newer versions will be better, with a better chuck and better anvil, and a stronger motor/hammer for a higher torque output. The overall design is light and maneuverable in confined spaces, great for working under the hood or in cramped work spaces. Improvements that could be had: Stronger motor/hammer A more robust chuck design, current chuck is not very secure, barely enough to hold onto most standard sized bits. Adjustable speed settings not exclusive to trigger pressure, or perhaps different modes (driver mode/breakaway mode, etc) A better light, multi-bulb ring around the collet is growing in popularity for goos reason. Overall a good investment, highly recommend.

Smooth running tools and extremely strong

The bit is stuck. The whole chuck is not working .