My mechanic is changing the oil gallery gasket due the well know low oil pressure problem on HR engines. As the front cover is removed and the engine has 230.000 km, he check the primary chain. It is stretched. So he remove the camshaft sprockets in order to change all 3 chains plus guides plus tensioners.
Then he realizes a very high wear on timing sprockets (4 cam gears plus crank gear). I didn’t make photos yet, but the wear are similar to the photographs attached at the botom of the post found on the net
The wear mark are simetrical on both sides of e