Tensioner Pulley, timing belt

Service instructions:
There are two different drive systems. Volvo does not give a year, yet an engine number to differentiate between them. It must therefore be checked on the car.
1) The timing belt is mechanically fitted.
 (The tensioner is pressed on the belt with a spring.
2) The timing belt is tensioned hydraulically
 (The tensioner is a hydraulic cylinder pressed against the belt)

744, 745. All models with engines B204- and B234F. See additional information
780. All models with engines B204GT
944, 945. All models with engines B204E and B234-
964, 965. All models with engines B204FT

OEM# 3531186