Set basic position of camshafts - AR05.20-P-6020SX

ENGINES 273 in MODEL 216 

ENGINES 272, 273 in MODEL 221 

Fig 1: Identifying Camshafts Components (1 Of 3)

Courtesy of MERCEDES-BENZ USA

Fig 2: Identifying Camshafts Components (2 Of 3)

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Camshafts Components (3 Of 3)

Courtesy of MERCEDES-BENZ USA

	Remove/install
1	Switch off ignition
2	Remove air filter housing		AR09.10-P-1150SX
	Risk of death  when touching components on vehicles with high-voltage on-board electrical system	Do not touch components and open lines of the high-voltage on-board electrical system. Persons who are carriers of electronic implants (e.g. cardiac pacemakers), must not carry out any work on high-voltage on-board electrical systems.	AS54.00-Z-0001-01A
3	Perform disable for the high-voltage on-board electrical system	Model 221.095/195 After completing the work, attach initial startup event log together with the disconnection log to the vehicle file.	AR54.10-P-1150SXH
	Note on the voltage on-board electrical system		AH54.00-P-0010-01A
4	Remove front covers from cylinder heads	Left cylinder head	AR01.30-P-5700SX
		Right cylinder head	AR01.30-P-5700SY
5	Remove centrifuge		AR01.20-P-2100SX
6	Rotate engine at center bolt on crankshaft in direction of engine rotation to a 40° crank angle after ignition TDC and then check position of camshafts		AR05.20-P-6010-01VB
			Figure
7	Lock gear backlash compensation for camshaft adjusters (13, 14)		AR05.20-P-7201-05VA
8	Detach center valves (5, 6, 7)	Observe loosening direction.	AR05.20-P-7201-06VA
			*BA05.20-P-1009-02A
9	Remove cylinder head covers	Left cylinder head cover	AR01.20-P-5014SX
		Right cylinder head cover	AR01.20-P-5014SY
10	Remove center valves (5, 6) of camshaft adjuster (13, 14) and remove pulse wheel (9, 10)	Check dowel pins (18) and pins (19). If a dowel pin (18) or pin (19) is sheared off, this must be removed from camshaft adjuster (13, 14). Always replace pulse wheels (9, 10). When tightening central valve (5, 6) there is the risk of a dowel pin (18) or pin (19) shearing off at pulse wheels (9, 10). Lubricate central valves (5, 6) for assembly on contact surfaces to pulse wheels (9, 10). Align pulse wheels (9, 10) dowel pin (18) to fitted bores (20) in camshaft adjusters (13, 14).
11	Counterhold exhaust camshafts (1, 2) at the rear using a suitable tool and detach camshaft adjuster (13, 14) to the front from the exhaust camshafts (1, 2)	Before assembly of camshaft adjusters (13, 14) lubricate contact surfaces on exhaust camshaft (1, 2) and camshaft adjusters (13, 14). Align dowel pins (21) in camshaft adjusters (13, 14) to fitted holes (22) in exhaust camshafts (1, 2) and install camshaft adjusters (13, 14) in their basic position:
		See "Check basic position of camshafts".	AR05.20-P-6010-01VB
12	Remove auxiliary bearing cap (17) and exhaust camshaft (1)		*BA05.20-P-1010-02A
13	Remove chain tensioner	Install new chain tensioner  . The previously installed chain tensioner must not be reinstalled because during removal, its pressure pin is pressed into the end position. The thrust pin latch prevents this return stroke. This would overstretch the timing chain on reinstalling.	AR05.10-P-7800SX
14	Remove tensioning rail bolt (23)	Apply sealant to tensioning rail bolts (23) before assembly.	AR01.30-P-5800-04V
			Figure
			Figure
		Loctite 5970 sealant	*BR00.45-Z-1013-01A
15	Pull tensioning rail (24) up and out of timing case
16	Remove center valve (7) on camshaft adjuster (15) and pulse wheel (11)	Check dowel pin (18) and pin (19). If a dowel pin (18) or pin (19) is sheared off then this must be removed from camshaft adjuster (15). Always replace pulse wheel (11). When tightening center valve (7) there is a risk that dowel pin (18) or pin (19) may shear off at pulse wheel (11). Before assembling, lubricate center valve (7) at contact surface to pulse wheel (11). Align dowel pin (18) for pulse wheel (11) with fitted bore (20) in camshaft adjuster (15).
17	Remove timing chain from camshaft adjuster (15) and detach camshaft adjuster (15) forwards from intake camshaft (3)	Lubricate contact surfaces on intake camshaft (3) and camshaft adjuster (15) before assembling camshaft adjuster (15). Align dowel pin (21) in camshaft adjuster (15) to fitted bore (22) in intake camshaft (3) and install camshaft adjuster (15) in its basic position:
		See "Check basic position of camshafts".	AR05.20-P-6010-01VB
18	Remove timing chain from camshaft adjuster (16) and turn camshaft adjuster (16) in basic position	See "Check basic position of camshafts".	AR05.20-P-6010-01VB
19	Install in the reverse order
	Checking
	Risk of accident  caused by vehicle starting off by itself when engine is running. Risk of injury  caused by contusions and burns during starting procedure or when working near the engine as it is running	Secure vehicle to prevent it from moving by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
20	Conduct engine test run and check engine for leaks

Fig 4: Identifying Wrench Socket (001 589 65 09 00)

Courtesy of MERCEDES-BENZ USA

Fig 5: Identifying Threaded Stud (116 589 01 34 00)

Courtesy of MERCEDES-BENZ USA

Fig 6: Identifying Impact Extractor (116 589 20 33 00)

Courtesy of MERCEDES-BENZ USA