As odd as it sounds, you do need a piece of wood. At least for the 617 engines. To change the mounts on these engines, you disconnect the engine shocks, then the motor mounts. To actually lift the engine, you place a piece of wood between your floorjack and the oil pan. This is just to prevent damage. You actually lift the engine by the oil pan. You have to keep an eye on the radiator fan and the upper radiator hose.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member