The timing chain tensioner in its version with the metal rail (see left picture below) was a very weak part.
At most of the engines with damages at the timing chain or the valve train the tensioner spring broke before and caused a chain reaction. In function, the spring draws this rail into atensioning position, putting some pressure onto the chain run.
Unfortunately the loops of the spring (see picture on the right) will break very easily due to vibrations.
This problem was recognized at the Victoria plant, and they did a redesign of the complete tensioner (see right picture below), which also could be put into earlier engines. There now was a plastic material instead of the metal rail, now being held in position by a compression spring.
This version is absolutey reliable, as the compression spring works without problems.
These parts we had available in the genuine Victoria package till some time ago.
As they went out, we decided to have a remanufactured version using a modern plastic, a material that is also used in the automobile industry for exactly this purpose. The compression spring could have been reinforced by increasing its wire diameter by 0,1 mm.