Originally Posted by forza370z

Sorry I didn't explain this well... Lol. So basically most aftermarket clutches have high spring load that will add extra force on the main thrust bearings when you depress the clutch and cause premature main thrust bearing wear. If the thrust bearings wear out it will cause the "Crank Walk" and eventually engine failure. This won't happen immediately but after 30k-40k driving. My friend's 350 had this issue. He had to rebuild the engine. My mechanic friend who worked on vqs for 12 years told me bypass the clutch start switch is a must for those clutches(that includes the JWT). However, while I am doing researches I found Z1 pointed this out and claimed their clutch has the low spring load while still keeping the high clamping force which looks pretty promising to me. That's why I want to ask you guys that have JWT or Southbend clutches on your car for a while has encountered anything like that.

Here is the quote from Z1:

The pressure plate in this kit exceeds OEM specifications and features high clamping force while maintaining a low spring load. A low spring load eases lateral force on the main thrust bearings in your engine which is especially important during "dry" start-up. (High pressure plate spring loads result in high lateral forces being exerted on the crank when the pedal is depressed and the clutch is disengaged which can cause premature thrust bearing failure resulting in "crank walk" and ultimately engine failure).

Z1 370Z / G37 Clutch and Flywheel Combo