GTR/GR6 1st Gear and Input Shaft
The biggest headache of the GR6 is the notorious 1st gear. The unit needs to be torn down completely in order to replace it and this is where most of the labor involved with parts replacement ends up. This is a must, though, for anyone serious about modifying their GT-R.
Note in the picture below how much bigger the Jacks Trans 1st gear is over OEM:
Jacks Trans was also nice enough to include an upgraded retaining clip with the input shaft to save on the costs associated with using an aftermarket retainer.