300SD (140.134) L6-3.5L DSL Turbo (603.971) (1993)
Timing Chain Tensioner: Service and Repair
Removal and installation of chain tensioner
Turbocharged engines:
Detach boost air hose (2) to valve body.
Remove chain tensioner (1),
Replace seat and install chain tensioner filled with SAE 10 engine oil.
Torque to 80 Nm.
Note: Chain tensioners which are the subject of problems should be replaced complete.
Filling chain tensioner with engine oil:
Place chain tensioner with the plunger bolt downwards in SAE engine oil until over the collar on the hexagon. Press plunger up to the stop 7 - 10
times slowly with the aid of a press or power drill.
It should be possible to compress the chain tensioner quite slowly, evenly and with little effort after filling with oil.
Note: A modified valve disk (231) has been installed in the chain tensioner since 08/84 in order to limit to peak pressures of the chain
tensioner on the tensioner rail.
225
Sealing plug
226
Aluminium gasket A 25 X 30
227
5 mm dia. ball
22B
Ball guide