just had my tensioner out due to replacing the timing chain. It is automatic, to a point. it will get tighter, but not looser. It is spring loaded. there are 3 parts to the tensioner. The body, the ram, the spring bolt. I cleaned mine with brakeclean and then put some motor oil on the threads and spring. You install it in 2 parts. The ram gets screwed into the body, then it is installed in the head. Once it is installed, the spring bolt gets installed and torqued. This spring will then force the ram out to the chain guide to apply pressure.