Remove/Install Timing Chain Tensioner - AR05.10-P-7800MSC

Engine 256.9 In Model 167 

Courtesy of MERCEDES-BENZ USA

Fig 1: Timing Chain Tensioner Components Location - Engine 256.9 In Model 167

Courtesy of MERCEDES-BENZ USA

	Risk of injury  to skin and eyes due to handling of engine oil. Risk of poisoning  caused by swallowing engine oil	Wear protective gloves, protective clothing and safety glasses. Do not fill engine oil into beverage containers.	AS18.00-Z-0001-01A
	Risk of injury  caused by scraping or cutting body parts on sharp vehicle parts	Always wear protective gloves when working on or near sharp and non-deburred vehicle parts. Deburr repair panels.	AS00.00-Z-0017-01A
Topical note	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Remove/install
1	Remove exhaust gas aftertreatment unit.		AR49.20-P-1500MSC
2	Remove screws (9) and remove heat shield (8).	M6 X 1	*BA00.10-P-1002-04A
		Bolt, heat shield to timing case	*BA22.10-P-1005-02A
		Bolt, heat shield to crankcase	*BA22.10-P-1004-02A
3	Remove bracket of 48 V wiring harness from bracket (6) and place to one side.	M6 X 1	*BA00.10-P-1002-04A
4	Remove screws (7) and remove bracket (6).	Nut/bolt, holder for catalytic converter to crankcase	*BA49.10-P-1007-02P
5	Remove screws (2) and remove cap (1).	: Replace cap (1). Screw/bolt, chain tensioner housing cover to crankcase	*BA05.10-P-1006-01MRT
6	Remove chain tensioner (4) and collect escaping engine oil using a rag.	: Only reuse chain tensioner (4) if it has had no noticeable problems in previous operation and no chain drive components have been replaced. Engine damage will occur otherwise. Chain tensioner (4) is pretensioned via an internal spring and extends fully during removal. : Replace sealing ring (5). Chain tensioner at crankcase	*BA05.10-P-1003-01MRT
	Check
7	Check whether the chain tensioner (4) is fully extended.	If chain tensioner (4) has not fully extended, ↓ replace chain tensioner (4).
8	Install in the reverse order.
9	Check and correct engine oil level.		AP18.00-P-1812SKI

METRIC SCREWS/BOLTS AND NUTS AS PER MBN 10 105, 10 143

Number	Designation		8.8	10.9
BA00.10-P-1002-04A	M6 X 1	Nm	9	13

CAMSHAFT POSITIONER, TIMING CHAIN DRIVE

Number	Designation		Engine 256.9
BA05.10-P-1003-01MRT	Chain tensioner at crankcase	Nm	80

CAMSHAFT POSITIONER, TIMING CHAIN DRIVE

Number	Designation		Engine 256.9
BA05.10-P-1006-01MRT	Screw/bolt, chain tensioner housing cover to crankcase	Nm	8

ENGINE SUPPORT (ENGINE SIDE)

Number	Designation		Engine 256
BA22.10-P-1004-02A	Bolt, heat shield to crankcase	Nm	8

ENGINE SUPPORT (ENGINE SIDE)

Number	Designation		Engine 256
BA22.10-P-1005-02A	Bolt, heat shield to timing case	Nm	8

EXHAUST SYSTEM

Number	Designation		Model 167 with engine 256
BA49.10-P-1007-02P	Nut/bolt, holder for catalytic converter to crankcase	Nm	20