300CD (123.153) L5-3.0L DSL Turbo (617.952) (1982)
A Rocker arm inductance-hardened and hard-chromed
B Rocker arm with carbide facing
Since the above measures result in higher loads on camshafts, a different materials pairing between camshaft and rocker arm has been required.
Camshafts of engine 617.950 (USA) model year 1980 with increased output and of engines 617.951/952 (code number 05) are made of chilled cast iron,
and the sliding surface of the respective rocker arms is provided with a brazed-on carbide facing (B, arrow).
Camshaft bearings 2, 3 and 4
Engines without increased output D = 46.5 mm
Engines with increased output D = 49.0 mm
Because of the larger valve lift (higher cams) and in order to permit installation of camshaft, the bearing diameter (D) at camshaft bearings 2, 3 and 4 had
to be increased by 2.5 mm. Accordingly, the diameter of bearing journals 2, 3 and 4 of camshaft has also been increased by 2.5 mm.