Remove/install belt drive components - AR13.20-P-0001GZA

ENGINES 272, 273 in MODEL 164, 251 

Fig 1: Identifying Belt Drive Components

Courtesy of MERCEDES-BENZ USA

	Removing
	Risk of injury  caused by moving parts that 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
1	Remove front engine cover
2	Detension poly-V belt (2), remove and detension tensioner pulley (3)	To do this use a hexagon (2) on the poly-V belt tensioning device (4).
	Checking
3	Check profile of belt pulley and poly-V belt tensioning device (4) for damage and soiling
4	Check poly-V belt (2) for wear and damage and replace if necessary
	Check visible area of poly-V belt for wear	Model 164.1 with engine 272.9, 164.8 with engine 273.9	AP13.22-P-1352GZC
		Model 251.065/ 165 Model 164.1 with engine 273.9, 251.054/ 056/072/ 154/ 156/ 172	AP13.22-P-1352RTC
	Remove/install	Only perform steps 5 through 9 for remove/ install of poly-V belt tensioning device (4).
5	Remove electric fan	Model 164 with engine 273	AR20.40-P-5000GZA
6	Lock poly-V belt tensioning device (4)	Swivel poly-V belt tensioning device (4) at hexagon (2a) in an anti-clockwise direction and lock in place using drift (03).
7	Remove bolts (2b) and poly-V belt tensioning device (4)		*BA13.25-P-1001-01P
8	Unclamp poly-V belt tensioning device (4)	When replacing poly-V belt tensioning device (4) Clamp poly-V belt tensioning device (4) in a vise, swivel at hexagon (2a) in an anti-clockwise direction, pull out drift (03) and slacken poly-V belt tensioning device (4). Installation:  The poly-V belt tensioning device (4) can only be installed when locked.
9	Install in the reverse order
	Remove/install	Only perform steps 10 through 12 for remove/install of guide pulleys (5).
10	Remove covers for guide pulleys (5)
11	Remove bolts to guide pulleys (5) from coolant pump and take off		*BA20.10-P-1004-01U
12	Install in the reverse order
	Install
13	Fit on and tension (2) as per routing diagram and tension	To do this use a hexagon (2) on the poly-V belt tensioning device (4). Do not use wax or similar products, as this may cause poly-V belt (2) to slip.	AR13.22-P-3902-02VA
14	Fit front engine cover

BELT TENSIONING DEVICE

Number	Designation		Engine 272	Engine 273
BA13.25-P-1001-01P	Bolt from poly-V belt tensioning device to timing case cover	Nm	35	35

COOLANT PUMP, COOLANT THERMOSTAT

Number	Designation			Engine 272	Engine 273
BA20.10-P-1004-01U	Bolt, guide pulley between water pump and belt tensioner	Initial installation	Nm	35	35
		Follow-up operations	Nm	25	25