Remove/install camshafts - AR05.20-P-7201MMB

ENGINE 157, 276, 278 in MODEL 221 

ENGINE 157, 278 in MODEL 216 

Shown on engine 278 

Fig 1: Identifying Camshafts Remove/Install Components - Shown On Engine 278

Courtesy of MERCEDES-BENZ USA

	Risk of injury  caused by fingers being jammed or pinched when removing, installing or aligning hoods, doors, trunk lid/rear-end door or sliding roof.	No parts of the body or limbs should be within the operating area when the components are moving.	AS00.00-Z-0011-01A
	Remove/Install
1	Rotate engine at crankshaft center bolt in direction of engine rotation to a 40°crank angle (CA) after top dead center (TDC) on cylinder 1 (ignition TDC)		AR05.10-P-7620-04MM
2	Remove respective cylinder head cover	Engine 276 - left cylinder head cover	AR01.20-P-5013MMA
		Engine 276 - right cylinder head cover	AR01.20-P-5012MMA
		Engine 157, 278 - left cylinder head cover	AR01.20-P-5013MMB
		Engine 157, 278 - right cylinder head cover	AR01.20-P-5012MMB
3	Mount hold-down tool on camshafts (4)	Tie-down set	Figure
4	Remove chain tensioner	ENGINE 276 in MODEL 221	AR05.10-P-7800MMA
		ENGINE 157, 278 in MODEL 216, 221	AR05.10-P-7800MMB
5	Loosen control valve (2) and remove	To loosen and tighten control valve (2) the camshafts (4) must be counterheld at their rear ends by a helper using a Torx T 60. The thread and bolt head contact surface of the control valve (2) must be oiled. The control valve (2) must be tightened down evenly without  discontinuity with torque.
		Center valve, pulse wheel/camshaft adjuster to camshaft	*BA05.20-P-1009-02A
		Socket	Fig 2
6	Remove camshaft positioner (1) from camshaft (4)		AR05.20-P-6020MMB
		The camshaft positioners (1) must not be mixed up with each other. Check basic position of camshaft (4) or adjust.
7	Remove timing chain (3) from camshaft positioners (1)	The right hand timing chain (3) is placed first on the camshaft positioner (1) for the intake camshaft and then on the camshaft positioner (1) for the exhaust camshaft. The left hand timing chain (3) is placed first on the camshaft positioner (1) for the exhaust camshaft and then on the camshaft positioner (1) for the intake camshaft.
8	Install in the reverse order
	Risk of accident  from vehicle starting off by itself when engine running. Risk of injury  (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
9	Perform an engine test run and check engine for functionality

Fig 2: Identifying Socket (271 589 00 10 00)

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Tie-Down Set (276 589 01 40 00)

Courtesy of MERCEDES-BENZ USA