When installing a new gear set,
When the factory installs the gears in the brand new car the gear set they use is exact tolerance and tested for any noise, vibration or defects on the final line.
When you take that gear set out and replace it with any other, The gears need to be fitted properly and may need shims to get all of the tolerances correct. It is not so much doing a heat/cool cycle as it is to let the gears lap in (SET) Even with a new car they tell you not to run a steady speed but to vary the speed for at least a hundred miles or more to allow the transmission gears and rear end gears along with a few other things to seat (Break in).
It's not like it costs you a bunch of $$$ to do it properly. BUT
it may save you from having to redo the gear set because of noise and clunking.
2012-candy red- V-6 MCA, Automatic Trans. CFM Valve cover breather. MMD blackTail light trim.Magnaflow axle back street mufflers, JLT oil catch can.MMD hood struts.
Airaid Cold Air intake. red caliper covers, 3.7L performance engine cover, Flat black hood spears.Boss 302 strut brace, CDC rear panel, Trunk Cargo net,--Dash carpet cover,
Viser stickers to cover ugly yellow warning crap,Aluminum driveshafft and Swarr Bar.