1KZ Flywheel and Clutch Specifications

[AirheadNut]

Looking at options for a clutch for my TDI swap and was thinking maybe a 1KZ clutch would work well for dealing with the high torque of the 4-cylinder diesel. My transmission and adapter plate are for a 5VZ-FE, the input shaft spline is the same for both the 5VZ and the 1KZ, but I'm wondering how the clutch disc diameter and pressure plate bolt pattern compare between the two.

If not, is the crankshaft bolt pattern on the 1KZ the same as the 5VZ? Thinking I could possibly run a 1KZ flywheel instead of the 5VZ unit.

 

[AirheadNut]

From what I can find so far the 1KZ clutch disc is 260mm, the 5VZ clutch disc is 250mm. The 5VZ has a 120-tooth ring gear on the flywheel, does anyone know what the tooth count is on a 1KZ flywheel? Both are 8-bolt cranks, though I haven’t been able to determine if it’s the same bolt pattern.

 

[On spot]

1KZ has a 260 mm clutch with a recessed flywheel with 110 teeth. Crank bolt centers are 177 mm across and 30 from one to the other around the circle. Another potential issue you'll face is length of throw on the shift fork. The fork on my kz is cast not stamped.

 

[AirheadNut]

Fantastic info, thanks! Looks like a 1KZ SMF and clutch setup will probably not work without extensive modification to the adapter kit or a new, custom adapter. Definitely possible, but not something I want to undertake for a second time.