What transmission is in a 2002 Chevy Trailblazer 2wd?

The 2002 Chevy Trailblazer 2WD came with either a 4-speed automatic transmission (4L60-E) or a 5-speed manual transmission (depending on the trim level and options selected). There wasn't a standard across all models. You'll need to check the vehicle's documentation (owner's manual or the sticker on the driver's side doorjamb) to determine the exact transmission type.