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

ENGINE 275 in MODEL 216, 221

Fig 1: Identifying Chain Tensioner Components

G07541658

Courtesy of MERCEDES-BENZ USA

	Removing
1	Remove electric air pump (M33)		AR14.30-P-7251SZ
2	Remove air pump bracket	See Remove/install deceleration air valve.	AR09.40-P-3001SZ
3	Remove fan shroud	Model 216, 221 except 216.379, 221.179	AR20.40-P-6800SZ
		Model 216.379, 221.179	AR20.40-P-6800SXM
4	Position piston of cylinder 1 at a 20° crank angle after TDC	Rotate engine at the crankshaft in running direction until scribe mark for a 20° crank angle on pulley/vibration damper corresponds with scribe mark on timing case. The engine must not be turned back, otherwise timing chain can skip and this can result in engine damage.
5	Unscrew end piece (1) from chain tensioner housing (5) and remove sealing ring (2)		*BA05.10-P-1002-01H
6	Pull push spring (4) and filler pin (3) out of chain tensioner housing (5)
7	Remove chain tensioner housing (5) from timing case cover		*BA05.10-P-1003-01H
	Install
8	Installing chain tensioner	It is essential to follow chain tensioner installation sequence, otherwise the chain tensioner may not function correctly. Renew seals (2, 6).	AR05.10-P-7800-02VA
			*BA05.10-P-1002-01H
			*BA05.10-P-1003-01H
9	Install fan shroud	Model 216, 221 except 216.379, 221.179	AR20.40-P-6800SZ
		Model 216.379, 221.179	AR20.40-P-6800SXM
10	Install air pump bracket	See Remove/install deceleration air valve.	AR09.40-P-3001SZ
11	Install electric air pump (M33)		AR14.30-P-7251SZ
	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
12	Conduct engine test run and check the engine for leaks

TORQUE SPECIFICATION

Number	Designation		Engine 275, 285
BA05.10-P-1002-01H	End piece of chain tensioner	Nm	80
BA05.10-P-1003-01H	Chain tensioner housing in timing case cover	Nm	120