Replace timing chain - AR05.10-P-7601MM

ENGINE 157, 276, 278 in MODEL 221 

ENGINE 157, 278 in MODEL 216 

Fig 1: Identifying Timing Chain

Courtesy of MERCEDES-BENZ USA

Shown on engine 276 with I WIS timing chain 

	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 range of the mechanism when moving components.	AS00.00-Z-0009-01A
	Remove
1	Detach ground line from battery		AR54.10-P-0003SX
	Notes on battery		AH54.10-P-0001-01A
2	Remove camshafts with camshaft positioners		AR05.20-P-6992MM
		The camshaft positioners remain on the camshafts.
3	Determine variant of timing chain		AR05.10-P-7601-05MM
		There are two different variants of the chain drive which one can differentiate between simply by means of optical checking. For modification of the chain drive all parts engaging with the timing chain must be replaced.
4.1	Disconnect old timing chain (1)	Engines with IWIS timing chain
			AR05.10-P-7601-01MM
		Pressure screw	Fig 4
		Chain separating tool	Fig 5
		Case For a timing chain stretch, replace both secondary chains and the primary chain drive timing chain: ↓ Replace primary chain drive timing chain	Fig 6
		ENGINE 276	AR05.10-P-7612MMA
		ENGINE 157, 278	AR05.10-P-7612MMB
4.2	Disconnect old timing chain (1)	Engines with INA timing chain
			AR05.10-P-7601-01MMA
		Rivet press tool For a timing chain stretch, replace both secondary chains and the primary chain drive timing chain: ↓ Replace primary chain drive timing chain	Fig 3
		ENGINE 276	AR05.10-P-7612MMA
		ENGINE 157, 278	AR05.10-P-7612MMB
	Install
5	Draw in new timing chain (2) using an assembly link (04)		AR05.10-P-7601-04MM
		Case	Fig 6
		Assembly element	Fig 8
6.1	Rivet new timing chain (2)	Engines with IWIS timing chain
			AR05.10-P-7601-02MM
		Assembly insert	Fig 7
		Riveting tool	Fig 2
		Case	Fig 6
6.2	Rivet new timing chain (2)	Engines with INA timing chain
			AR05.10-P-7601-02MMA
		Rivet press tool	Fig 3
7	Install camshafts with camshaft adjusters		AR05.20-P-6992MM
		Only install cylinder head covers after checking the basic position of the camshafts.
8	Check basic position of the camshafts using the installed chain tensioner and correct if necessary		AR05.20-P-6020MMB
9	Connect ground line to battery		AR54.10-P-0003SX
	Notes on battery		AH54.10-P-0001-01A
	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
10	Carry out an engine test run, checking the engine for proper operation and leaktightness

Fig 2: Identifying Riveting Tool (602 589 00 39 00)

Courtesy of MERCEDES-BENZ USA

Fig 3: Identifying Rivet Press Tool (276 589 00 39 00)

Courtesy of MERCEDES-BENZ USA

Fig 4: Identifying Pressure Screw (602 589 05 63 00)

Courtesy of MERCEDES-BENZ USA

Fig 5: Identifying Chain Separating Tool (602 589 02 33 00)

Courtesy of MERCEDES-BENZ USA

Fig 6: Identifying Case (602 589 00 98 00)

Courtesy of MERCEDES-BENZ USA

Fig 7: Identifying Assembly Insert (278 589 01 63 00)

Courtesy of MERCEDES-BENZ USA

Fig 8: Identifying Assembly Element (271 589 09 63 00)

Courtesy of MERCEDES-BENZ USA