Remove/install chain tensioner - AR05.10-P-7800SZ

ENGINE 275 in MODEL 216, 221

Fig 1: Identifying Chain Tensioner Remove/Install Components

Courtesy of MERCEDES-BENZ USA

	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	Remove electric air pump (M33)		AR14.30-P-7251SZ
2	Remove air pump bracket		AR09.40-P-3001SZ
3	Remove fan shroud	Model 216, 221 except 216.379, 221.179	AR20.40-P-6800SZ
3	Remove fan shroud	MODEL 216.379, 221.179	AR20.40-P-6800SXM
4	Set piston of cylinder 1 to 30°CKA after TDC	The engine must not be turned back against the direction of engine rotation. The timing chain can skip otherwise and engine damage can occur. Rotate engine at the crankshaft in direction of engine rotation until scribe mark 30°CKA on belt pulley/vibration damper corresponds with scribe mark on timing case cover.
5	Remove the end piece (1) from chain tensioner housing (5) and remove sealing ring (2)	End piece of chain tensioner	*BA05.10-P-1002-01H
6	Pull compression spring (4) and filler pin (3) out of chain tensioner housing (5)
7	Remove chain tensioner housing (5) from timing case cover	Chain tensioner housing in timing case cover	*BA05.10-P-1003-01H
	Install
8	Install chain tensioner		AR05.10-P-7800-02VA
		The installation sequence of the chain tensioner must be observed. Correct operation of chain tensioner is not guaranteed otherwise. Renew sealing rings (2, 6).
		End piece of chain tensioner	*BA05.10-P-1002-01H
		Chain tensioner housing in timing case cover	*BA05.10-P-1003-01H
9	Install fan shroud	Model 216, 221 except 216.379, 221.179	AR20.40-P-6800SZ
9	Install fan shroud	MODEL 216.379, 221.179	AR20.40-P-6800SXM
10	Install air pump bracket		AR09.40-P-3001SZ
11	Install electric air pump (M33)		AR14.30-P-7251SZ
	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
12	Perform an engine test run and check engine for leaktightness

TIMING CHAIN, CHAIN TENSIONER

Number	Designation		ENGINE 275, 285
BA05.10-P-1002-01H	End piece of chain tensioner	Nm	80

TIMING CHAIN, CHAIN TENSIONER

Number	Designation		ENGINE 275, 285
BA05.10-P-1003-01H	Chain tensioner housing in timing case cover	Nm	120