Gear box reassembly - chuck spins very slowly

Hey all,

I picked up and old used cordless drill ( model # 2606-20, 18v 1/2" driver). It was essentially free, part of a small lot of drills I bought for cheap. So I wanted to clean it up, see if it worked (it didn't have a battery), etc.

I found a battery and confirmed that it did work. Generally it all seemed decent - at least functional.

I took it apart, cleaned up various things... including disassembling much of the gear box section (not all of it, but say 2/3). When I reassembled things... and figured out that the magnet ring was backwards :) ... I tried it out. The motor spun, the shaft spun... but the chuck was spinning very slowly. Like I had turned a gear increaser into a reducer. So say 10-20 RPM instead of... ~450.

So I took it all apart again, this time disassembling the entire gear box and including the chuck assembly... put it back together - still turns very slowly.

I have reviewed various disassembly videos and some assembly diagrams... I think I'm doing it right.

I know it can be really hard to troubleshooting something like this without seeing it, without really knowing what I did... I'm pretty handy with tools and things (spent 15 years working as a maintenance technician in a wafer fab) - so not a complete noob. But nearly always the first time you do something it's not perfect - I'm missing something here, obviously. :)

Anybody have any thoughts about what I messed up?