Inspect valve stroke

AR05.00-W-1500A

Inspect valve stroke

06.08.2014

ENGINE

902.9 in MODEL 957

with CODE MS8 (Natural gas engine)

ENGINE

904.9 in MODEL 374.4

ENGINE

904.9 in MODEL 375, 673, 674, 676, 958, 970, 972, 975, 976

ENGINE

904.904 in MODEL 670

ENGINE

904.908/914/923/936 in MODEL 668, 670

ENGINE

906.9 in MODEL 374, 375, 950, 952, 953, 954, 957, 958

ENGINE

906.9 in MODEL 958, 970, 972, 974, 975, 976

Shown on ENGINE 904.9

1

Rocker arm

2

Valves

3

Push rod

4

Dial indicator holder

5

Mount dial indicator

6

Valve spring

7

Valve bridge

A

Valve clearance

B

Valve lift



Firing order

AH01.00-N-0100-01AA



Remove

1

Remove cylinder head cover

Engine 904.9 in model 375, 668, 670, 673, 674, 676, 958, 970, 972, 975, 976; engine 906.9 except code MS8 (Natural gas engine)

AR01.20-W-5014A

ENGINE 902.9, 906.9 with CODE MS8 (Natural gas engine)

AR01.20-W-5014H

 ENGINE 904.9 in MODEL 374.4
No instructions were created yet for this variant.

2

Attach cranking device

AR03.30-W-1600-03A

 Bolt, turning device to timing case

*BA01.60-N-1003-01A

 Turning device

*904589046300



Check

3

Crank engine with cranking device until piston of cylinders to be inspected is positioned at ignition TDC

 Both push rods (3) can be turned and valve clearance (A) is available at both rocker arms (1).

4

Check valve clearance (A); adjust if necessary



Model 668, 670

AP05.30-D-0560A



Model 374.5, 375, 673, 674, 676, 950, 952, 953, 954, 957, 970, 972, 974, 975, 976

AP05.30-W-0560B

 Model 374.4, 958
No instructions were created yet for these variants.

5

Mount dial indicator holder (4) on cylinder head and measuring tip of dial indicator (5) onto valve spring retainer of valve spring (6) for exhaust valve or onto valve bridge (7) for inlet valve

 Mount dial indicator (5) with a preload of about 15 mm so that the measuring travel at dial indicator (5) is adequate for the valve lift (B).

 Dial gage

*001589532100

 Dial indicator holder

*363589022100

6

Set scale of dial indicator (5) to "0"

 Dial gage

*001589532100

7

Crank engine with cranking device in direction of engine rotation and read off valve stroke (B)

 The maximum valve lift (B) is displayed before the dial indicator (5) moves in the opposite direction. The valves (2) are fully open at this point.

Valve lift with specified valve clearance

*BE05.30-N-1002-01B

If the read off valve lift (B) is smaller than the specified value:



Check cam of the camshaft for wear, possibly:

Remove camshaft and inspect.
Engine 902.9, 906.9; engine 904.9 in model 375, 668, 670, 673, 674, 676, 958, 970, 972, 975, 976

AR05.20-W-6292A

 ENGINE 904.9 in MODEL 374.4
No instructions were created yet for this variant.

8

Carry out inspection at all valves (2)



Install

9

Install cylinder head cover

Engine 904.9 in model 375, 668, 670, 673, 674, 676, 958, 970, 972, 975, 976; engine 906.9 except code MS8 (Natural gas engine)

AR01.20-W-5014A

ENGINE 902.9, 906.9 with CODE MS8 (natural gas engine)

AR01.20-W-5014H

 ENGINE 904.9 in MODEL 374.4
No instructions were created yet for this variant.

10

Remove turning device

AR03.30-W-1600-03A

 Inspection hole cap to timing case

*BA01.60-N-1002-01A

Check values for valves

Number

Designation

ENGINE 902.9, 906.9 with CODE MS8

ENGINE 904.9## ## up to 039739, ENGINE 906.9## ## up to 041955 except CODE MS8

BE05.30-N-1002-01B

Valve lift with specified valve clearance

Inlet

mm

9,7

9,7

Outlet

mm

10,7

10,7

Check values for valves

Number

Designation

ENGINE 904.9## ## as of 039740, ENGINE 906.9## ## as of 041956 except CODE MS8

BE05.30-N-1002-01B

Valve lift with specified valve clearance

Inlet

mm

9,7

Outlet

mm

10,7

 Timing case

Number

Designation

ENGINE 900.9, 902.9, 904.9, 906.9

BA01.60-N-1002-01A

Inspection hole cap to timing case

Nm

25

 Timing case

Number

Designation

ENGINE 900.9, 902.9, 904.9, 906.9

BA01.60-N-1003-01A

Bolt, turning device to timing case

Nm

25