Remove/install tensioning rail - AR05.10-P-8127GZA (ML350, ML550, GL450, GL550)

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ENGINES 272, 273 in MODEL 164, 251

Fig 1: Identifying Tensioning Rail - Shown On Engine 272 Up To Engine Number 30089231

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 2: Identifying Tensioning Rail - Shown On Engine 272 From Engine Number 30089233

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 3: Identifying Camshaft Adjuster For Intake Camshaft

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 4: Identifying Dowel Pin In Pulse Wheel

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 5: Identifying Dowel Pin In Camshaft Adjuster

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

MODIFICATION NOTES

14.9.07

Use the Torx screwdriver bit T60 to counterhold camshafts, added

AR05.20-P-7201-06VA

	Remove/install
	Risk of injury caused by fingers being pinched or crushed when removing, installing or aligning hoods, doors, trunk lids, liftgates or sliding roof	Keep body parts and limbs well clear of moving parts.	AS00.00-Z-0011-01A
1	Open engine hood	Only close engine hood after carrying out a leaktightness check.	AR88.40-P-1000GZ
2	Remove air filter housing		AR09.10-P-1150GZA
3	Remove front covers from cylinder heads	Right cover	AR01.30-P-5700GZC
		Left cover	AR01.30-P-5700GZA
4	Remove centrifuge		AR01.20-P-2100GZA
	Checking
5	Turn the engine at the crankshaft center bolt in the direction of engine rotation to 40° after ignition TDC and check the position of camshafts		AR05.20-P-6010-01VB
6	Lock the gear backlash compensation of the exhaust camshaft adjuster (9) at the right exhaust camshaft	The tooth flanks are held against each other by spring pressure and should not be skewed, otherwise the exhaust camshaft adjuster (9) will be irreparably damaged	AR05.20-P-7201-05VA
7	Loosen the exhaust camshaft center valve (5) on the right exhaust camshaft	Observe loosening direction. Counterhold the exhaust camshaft at the rear. Do not remove exhaust camshaft (5) center valve.	AR05.20-P-7201-06VA
			*BA05.20-P-1009-02A
8	Remove the right cylinder head cover		AR01.20-P-5012GZA
9	Remove the exhaust camshaft center valve (5) of the right exhaust camshaft and remove exhaust camshaft pulse wheel (7)	Check on the pulse wheel whether the dowel pin (15) or pin has been sheared off. Remove the sheared pin or the pulse wheel dowel pin (15) from the exhaust camshaft adjuster (9). Installation: Always replace exhaust camshaft pulse wheel (7). When tightening the exhaust camshaft center valve (5), there is a risk of shearing off the dowel pin (15) and pin at the exhaust camshaft pulse wheel (7). Oil the exhaust camshaft center valve (5) at the contact surface with the pulse wheel before assembling. Installation: Align the pulse wheel dowel pin (15) on the pulse wheel with bore (14) in the camshaft adjuster.
10	Pull the exhaust camshaft adjuster (9) forwards and away from the right exhaust camshaft, while counterholding the exhaust camshaft at the rear.	Installation: Align the camshaft adjuster dowel pin (16) in the camshaft adjuster with bore (17) in the exhaust camshaft.
11	Remove the exhaust camshaft auxiliary bearing cap (11) on the right exhaust camshaft and take out the exhaust camshaft		*BA05.20-P-1010-02A
12	Remove chain tensioner	Chain tensioner with thread M24 x 1.5	AR05.10-P-7800GZA
		Chain tensioner using thread M22 x 1.5 For engine 273, only chain tensioner using thread M22 x 1.5 is installed.	AR05.10-P-7800GZG
13	Remove tensioning rail bolt	Installation: Apply sealant to tensioning rail bolts before installation.	AR01.30-P-5800-04V
			Fig 6
			Fig 7
		Sealant	*BR00.45-Z-1013-01A
14	Pull tensioning rail (1a) upwards and out of timing case
15	Install in the reverse order

CAMSHAFT, CAMSHAFT ADJUSTMENT

Number	Designation		Engine 272	Engine 273
BA05.20-P-1009-02A	Center valve for pulse wheel/camshaft adjuster to camshaft	Nm	145	145
BA05.20-P-1010-02A	Bolt, auxiliary bearing cap to cylinder head	Nm	8	8

Fig 6: Identifying Threaded Stud (116 589 01 34 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Fig 7: Identifying Impact Extractor (116 589 20 33 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

REPAIR MATERIALS

Number	Designation	Order number
BR00.45-Z-1013-01A	Loctite 5970 sealant	A 003 989 98 20