Clutch pedal adjustment rod

Hi all, just did a clutch/flywheel job on my gfs truck, got new parts in and pressure, however the clutch lets out very high (at almost full return to resting position).

ive been trying to mess around with the adjustment rod, loosened the 12mm lock nut and held the 14mm with wrench while trying to spin the rod but it’s so stiff! I can’t turn by hand and I might get a 1/16th of a turn with vice grips. Any suggestions would be greatly appreciated thanks!

 

All I got is this:

 

It sounds like it already has preload on it or bad corrosion. Loosen the jam nut a bunch and thread the rod further into the 14mm side of plunger which will be loosening it up. After it's loosened up it should spin freely with finger tips. You can generally spin it until you hit resistance and tighten the jam nut and you'll be close in adjustment.