[Jim Sims]

Depends on the interference resulting from the parts tolerances and factory swaging (peening) but even taking advantage of the thermal expansion/contraction you are likely to require a large heavy vise or hydraulic shop press to assemble the parts. IMO and experience a soft mallet is not likely to work. I use a hot air gun to heat the dogteeth and a hydraulic shop press to push them onto the gear. Given the currrent cost of these parts it's worth locating a shop press for this operation. In fact, if you ruin the gear and dogteeth you could likely buy two or three shop presses from Harbor Freight for the cost of the ruined parts.