I find that the gearboxes are the most enjoyable part.
The Willys Jeep MOC has a nice 4-speed H-pattern gearbox as part of the build.
I made a schoolboy error early on this build though, and put one of the diffs in the wrong way round which resulted in the front and rear wheels turning in opposite directions when you turn the prop shaft. Oops!
All sorted now though.
oh I enjoyed the gearbox, I did look at some tips online when I started as it was the first part you start with, and I didn’t want it to be in-correct as it was my first car using a gearbox.
One thing I did was use a very fine flat bladed screw driver and made sure none of the cogs were flush against something creating any friction I just centred it and the gear changes seem very smooth.
The box and instructions for this set are brilliant as well.