One of the few problems many have reported with the TongSheng TSDZ2 system is a weak gear cog. It’s made from a blue nylon and apparently wears out quite quickly. To avoid that problem I’m replacing it with one a company in China manufacturers that’s made from metal instead. Not sure which metal it’s made from but by all accounts it seems to do the job well. Install and results will be posted hopefully later this coming week when it arrives. I’ll also report on if it introduces much noise as for the life of me that’s the only reason I can think of that would cause TongSheng not to install it from the off.