Set Basic Position Of Camshafts - AR05.20-P-6020MNL

Engine 176 in model 217, 222

MODIFICATION NOTES

04.07.2022

Document completely revised.

Shown on left cylinder head

Courtesy of MERCEDES-BENZ USA

Shown on left cylinder head

Courtesy of MERCEDES-BENZ USA

	Risk of injury . Skin or eye injuries may result when handling hot or glowing objects.	Wear protective gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of injury . Moving parts can pinch, crush or, in extreme cases even sever extremities.	No parts of the body or limbs should be within the operating area of mechanical components when moving components.	AS00.00-Z-0009-01A
	Risk of injury caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
	Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil	Wear protective gloves, protective clothing and safety glasses. Do not fill engine oil into beverage containers.	AS18.00-Z-0001-01A
Notice	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Remove
1	Remove cylinder head covers.	Left cylinder head cover	AR01.20-P-5013MNL
		Right cylinder head cover	AR01.20-P-5012MNL
2	Check size on camshaft and select correct special tool.		AR05.20-P-6027-01SZ
		Without this check, the incorrect special tool may be used. An incorrect repair right up to engine damage will otherwise occur.
		There are different sizes for camshafts.
		Holding device	Fig 2
		Holding device	Fig 1
3	Install brackets (1, 2, 3).		AR05.20-P-6020-03MNE
		Holding device	Fig 1
		Holding device	Fig 2
4	Turn engine at center bolt of the crankshaft through two revolutions, place engine on cylinder 1 at 40° KW after ignition TDC of cylinder 1 and mark with a drift.		AR01.10-P-1000-01SZ
		Only turn engine at the center bolt of the crankshaft in the direction of engine rotation using the specified box wrench. Otherwise, damage to the engine or even failure of the engine may occur.
		Measuring tool	Fig 7
		Ring wrench	Fig 3
		Drift	Fig 5
5	Remove left and right secondary chain drive chain tensioner.	Right secondary chain drive chain tensioner	AR05.10-P-7804MNL
		Left secondary chain drive chain tensioner Do not turn the engine while the chain tensioner is removed. Otherwise damage will occur. Remove left and right secondary chain drive chain tensioner without positioning the crankshaft.	AR05.10-P-7803MNL
6	Insert holding device (6) between camshaft positioners (7) and tighten.		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
7	Release camshaft positioners (7) from camshafts and remove with holding device (6).	Camshaft positioner (7) of right cylinder bank	AR05.20-P-7209MNL
		Camshaft positioner (7) of left cylinder bank	AR05.20-P-7208MNL
	Adjust
8	Turn camshafts in the basic position.		AR05.20-P-6027-01SZ
		The positions (arrows) of the camshafts must point upwards.
		Camshafts with ø 4 mm hole Socket wrench bit	Fig 4
		Camshafts with ø 5 mm hole Socket	Fig 6
9	Install forks (5).		AR05.20-P-6027-01SZ
		Install holders with forks (5) without major force application. Otherwise damage or incorrect timing will occur. Holders with forks (5) are not suited for bringing camshafts into position. Otherwise damage or incorrect timing will occur.
		Holding device	Fig 2
		Ring wrench	Fig 3
		Holding device	Fig 1
		Camshafts with ø 4 mm hole Socket wrench bit	Fig 4
		Camshafts with ø 5 mm hole Socket	Fig 6
	Install
10	Position camshaft positioners (7) at camshafts and slightly tighten control valves by hand and release by 1/4 turn.	Camshaft positioner (7) of right cylinder bank	AR05.20-P-7209MNL
		Camshaft positioner (7) of left cylinder bank	AR05.20-P-7208MNL
11	Install bracket (4).		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
12	Check that tensioning rails of secondary chain drive are seated centrally, and center if necessary.
13	Install left and right secondary chain drive chain tensioners.	Right secondary chain drive chain tensioner	AR05.10-P-7804MNL
		Left secondary chain drive chain tensioner Install secondary chain drive chain tensioners on left and right without turning the crankshaft.	AR05.10-P-7803MNL
14	Insert holding device (6) between the camshaft positioners (7) and tighten.		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
15	Tighten control valves of the camshaft positioners (7).	Camshaft positioner (7) of right cylinder bank	AR05.20-P-7209MNL
		Camshaft positioner (7) of left cylinder bank	AR05.20-P-7208MNL
16	Remove holding device (6).		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
17	Remove forks (5).		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
18	Remove drift from belt pulley.		AR01.10-P-1000-01SZ
		Drift	Fig 5
19	Turn engine at center bolt of the crankshaft through two revolutions, place engine on cylinder 1 at 400 KW after ignition TDC of cylinder 1 and mark with a drift.		AR01.10-P-1000-01SZ
		Only turn engine at the center bolt of the crankshaft in the direction of engine rotation using the specified box wrench. Otherwise, damage to the engine or even failure of the engine may occur.
		Measuring tool	Fig 7
		Ring wrench	Fig 3
		Drift	Fig 5
20	Install forks (5).		AR05.20-P-6027-01SZ
		Install forks (5) without major force application. Otherwise the timing will be off.
		Holding device	Fig 2
		Holding device If forks (5) cannot be installed without force application: ↓ Set basic position of camshafts again.	Fig 1
21	Remove forks (5).		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
22	Remove drift from belt pulley.	Holding device	AR01.10-P-1000-01SZ
		Drift	Fig 5
23	Remove holder (4).		AR05.20-P-6027-01SZ
		Holding device	Fig 2
		Holding device	Fig 1
24	Remove brackets (1, 2, 3).		AR05.20-P-6020-03MNE
		Holding device	Fig 2
		Holding device	Fig 1
25	Install cylinder head covers.	Left cylinder head cover	AR01.20-P-5013MNL
		Right cylinder head cover	AR01.20-P-5012MNL
26	Connect diagnostic system and perform initialization of timings.
			AD00.00-P-2000-04B
		For this purpose, start teach-in processes after engine replacement in diagnostic system under tab "Adaptations" in engine control unit and follow the instructions.