Supposedly you can adjust the lockup % on a Nismo GT differential by removing the right axle shaft and then use a 19mm socket to change the setting. Do you have to drain the diff fluid to do this? What is the easiest way to remove the axle?

 

No.
Dead blow hammer.

 

The adjustment you are referring to is the breakaway torque. Lockup is "adjusted" by restacking the clutch pack. SCC had an article on it. Daveh did a great writeup on it on hear. I used daveh post and the fsm to remove and restack my clutch pack to 77% lock, I did the math others call it 80%.

 

Thanks. Will adjusting (reducing) breakaway torque allow me to reduce oversteer while exiting corners, or do I have to swap plates? My lap times are suffering because the diff doesn't allow the tires to rotate at different speeds.
I saw daveh's writeup when it came out- pretty good info.

 

From the ATS site:Initial torque & cam angle

The initial torque (break away torque) is a pre-load torque on a LSD. Up to that torque load, the LSD locks the differential even without any rotational difference between the wheels. The initial torque and the cam angle on the cam rings determine the responsiveness of the LSD on the driver's steering and throttle inputs. The higher the initial torque and the higher the cam angle, the more responsive an LSD becomes. However, too much initial torque makes a vehicle extremely hard to turn and very high cam angle affect the vehicle's smoothness. A good performance LSD achieves an excellent balance of those two important factor

If you do decide to restack the plates make sure you have the selector at its lowest setting or the clutch packs and such won't fit in the housing. Took me a little while to figure it out when I did mine....live and learn now you don't have to.