If it's similar to the M103, the adjuster has a bracket that screws to the block and the PS mount (four screws, two on each end) that have to come out before the tensioner comes off. Center bolt pulls out.

I wish MB had used the same spring type as on the OM603, it's so simple and easy!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!