The Zook tensioner still uses a spring. Make sure the engine is at TDC and loosen the lock bolt and nut located on the side of the tensioner instead of the rear like the APE design. The spring inside the tensioner does all the tensioning forcing the plunger forward just like an automatic. You then just tighten the lock bolt and nut. There is no ratchet system or pawl to keep the tensioner from backing off if the lock bolt comes loose. The plunger is a smooth bore design with one side machined flat for the lock nut. Sounds screwy but if done right it works fine. The Zook microfiche has a good breakdown of how it works. I really wish it was an automatic as I get tired of dealing with it!More of a "semi-automatic" then. Kind of goofy.