Remove/install piston - AR03.10-P-7021GZB

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ENGINE 642 in MODEL 164

Fig 1: Identifying Piston Components

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

MODIFICATION NOTES

9.7.10

Value modified: Bolt, connecting rod cap to connecting rod, See picture

*BA03.10-P-1001-01L

	Removing
	Risk of injury caused by fingers being pinched or crushed when removing, installing or aligning hoods, doors, trunk lids, tailgates or sliding roof.	Keep body parts and limbs well clear of moving parts.	AS00.00-Z-0011-01A
	Risk of death caused by vehicle slipping or toppling off the lifting platform.	Align vehicle between columns of vehicle lift and position four support plates at vehicle lift support points specified by vehicle manufacturer.	AS00.00-Z-0010-01A
	Notes on self-locking nuts and bolts	All models	AH00.00-N-0001-01A
1.1	Remove engine		AR01.10-P-2400GZB
1.2	Remove engine with front axle carrier	Model 164	AR01.10-P-2500GZB
1.2	Remove engine with front axle carrier	Model 251	AR01.10-P-2500RTB
2	Remove transmission with torque converter	Model 164	AR27.10-P-0500GZ
2	Remove transmission with torque converter	Model 251	AR27.10-P-0500RTA
3	Detach engine from front axle carrier	Only when engine is removed downwards	AR01.10-P-2510GZB
4	Mount engine onto assembly stand
5	Remove cylinder head		AR01.30-P-5800GZC
6	Remove oil pan	Model 164	AR01.45-P-7500GZB
		Model 251 with 4MATIC	AR01.45-P-7500RTB
		Model 251 without 4MATIC	AR01.45-P-7500RTC
7	Remove oil pump		AR18.10-P-6020GZB
8	Mark right piston (4a), left piston (4b) and cylinder liners relative to one another.	The right piston (4a) and left piston (4b) must not be interchanged.
9	Remove connecting rods with right piston (4a) and left piston (4b)	If the arrow for the installation position of the right piston (4a) or of the left piston (4b) is no longer visible on the piston crown, remove carbonization and if necessary, identify the right piston (4a) or the left piston (4b) again.
10	Identify installation position of connecting rod (2) to the right piston (4a) and left piston (4b)
11	Remove circlip (5) from piston pin (6)	To prevent damage, place right piston (4a) and left piston (4b) on a clean and soft surface.
12	Press out piston pin (6)
	Install
13	Assign right piston (4a) and left piston (4b) to cylinder bore.
14	Oil piston pin (6) and connecting rod bush
15	Assemble right piston (4a), left piston (4b) and connecting rod (2) according to marked installation position.	The connecting rods (2) are cracked (broken). New connecting rods must be fitted following removal as the dimensional accuracy of connecting rods (2) after opening can not be guaranteed. The connecting rods are delivered with assembly bolts and have to be replaced by connecting rod bolts (3) with an assembly locking element.
16	Push in piston bolts (6) by hand
17	Insert circlip (5) for piston bolt (6) into the groove at right piston (4a) and left piston (4b)	To protect pistons from damage, place the right piston (4a) and left piston (4b) onto a clean and soft surface.
18	Clean and oil the right piston (4a) and left piston (4b).	For this purpose, clean and oil cylinder bores, connecting rod journals and connecting rod bearing shells
19	Align and tension the piston rings	Push on tensioning strap (7) over the piston rings and tension tensioning strap. Joint on upper piston ring must point in the direction of travel towards the front. The joints of other piston rings must be offset by 120° in each case.
19	Align and tension the piston rings	Tensioning strap	Fig 2
20	Insert the right piston (4a) and the left piston (4b) into the cylinder bores.	The arrow on piston crown must point to opposite cylinder bank. The connecting rod (2) must not be exposed at connecting rod journal of crankshaft while inserting; turn crankshaft accordingly.
21	Install connecting rod bearing cap (1)	The contact surfaces must be devoid of any oil and grease and must not be damaged.	AR03.10-P-6111-06TI
21	Install connecting rod bearing cap (1)		*BA03.10-P-1001-01L
22	Install oil pump		AR18.10-P-6020GZB
23	Installing oil pan	Model 164	AR01.45-P-7500GZB
		Model 251 with 4MATIC	AR01.45-P-7500RTB
		Model 251 without 4MATIC	AR01.45-P-7500RTC
24	Install cylinder head		AR01.30-P-5800GZC
25	Detach engine from assembly frame
26	Fit engine to front axle carrier	Only when engine is removed downwards	AR01.10-P-2510GZB
27	Mount the transmission with a torque converter on the engine	Model 164	AR27.10-P-0500GZ
27		Model 251	AR27.10-P-0500RTA
28.1	Install engine		AR01.10-P-2400GZB
28.2	Install engine with front axle carrier	Model 164	AR01.10-P-2500GZB
28.2	Install engine with front axle carrier	Model 251	AR01.10.P-25000RTB
	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
29	Check for leaks with engine running		AS00.00-Z-0005-01A

CONNECTING ROD

Number	Designation			Engine 642
BA03.10-P-1001-01L	Bolt, connecting rod cap to connecting rod	1st stage short arm	Nm	15
		2nd stage long arm	Nm	20
		3rd stage short arm	Nm	30
		4th stage long arm	Nm	40
		5th stage short arm	Nm	40
		5th stage short arm	∠°	90
		6th stage long arm	∠°	90
		7th stage short arm	∠°	90
		8th stage long arm	∠°	90
		See picture		AR03.10-P-6111-06TI

Fig 2: Identifying Retaining Strap (000 589 04 14 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.