Check/repair connecting rod

AR03.10-I-6111B

Check/repair connecting rod

2.8.11



Removing

1

Remove pistons

AR03.10-I-7021B

Checking

2

Perform visual inspection of connecting rod (1) and connecting rod bearing cap (2)

 If connecting rod (1) or connecting rod bearing cap (2) has a blue coloration or any damage is visible the whole connecting rod must be replaced.

3

Perform visual inspection of connecting rod bearing shells (3)

 No longer usable connecting rod bearing shells (3) must be replaced.



Notes on assessing wear on connecting rod bearings and connecting rod bearing journals

AH03.10-N-0001-03A

4

Check inside diameter of connecting rod bush
(5)

 If the measurement is no longer in the tolerance range the connecting rod must be replaced.

*BE03.10-N-1011-01B



*001589532100

Quick calipers for internal measurements

5

Check connecting rod (1) for distortion and dimensional accuracy

 The connecting rod (1) must not be repaired otherwise engine damage can occur; replace the connecting rod if necessary.

Distance (A)

*BE03.10-N-1014-01B

Permissible deviation from axial parallelism (B)

*BE03.10-N-1004-01B

6

Mount connecting rod bearing cap (2) without connecting rod bearing shell (3) on
connecting rod (1)


Observe marking on connecting rod bearing cap (2).

Mount connecting rod bearing cap (2) to fit exactly onto connecting rod (1).

Just put connecting rod bolts (4) in position, do not tighten.

7

Check basic bore of connecting rod bearing

 If one or both measurements are no longer in the tolerance range of the associated specified value the connecting rod must be replaced.

Permissible out-of-roundness of basic bore

*BE03.10-N-1005-01B

Inside diameter of basic bore for connecting rod bearing

*BE03.10-N-1002-01B



*001589532100

Quick calipers for internal measurements

8

Determine weight difference between connecting rods

 Only perform if more than two connecting rods were removed.

Weigh connecting rods (1) together with connecting rod bearing caps (2).

If the permissible weight difference is exceeded then the connecting rod with the greatest deviation must be replaced.

*BE03.10-N-1008-01B

9

Remove connecting rod bearing cap (2) from connecting rod (1)

10

Install and gauge connecting rod bearings

AR03.10-I-6111-06B

Connecting rod bearing inner Ø with connecting rod bearing shells inserted

*BE03.10-N-1001-01B

Outside diameter of connecting rod journal

*BE03.20-N-1004-02B



*BA03.10-N-1001-01B



*001589532100

Outside micrometer

Quick calipers for internal measurements

11

Check shank length of connecting rod bolts (4)

 On exceeding the permissible shank length the connecting rod bolt (4) concerned should be replaced.

Shank length of connecting rod bolt

*BE03.10-N-1013-01B



Install

12

Install pistons

AR03.10-I-7021B

Number

Designation

Engine
904.941

BE03.10-N-1001-01B

Connecting rod bearing inside Ø with connecting rod bearing shells inserted

Default

mm

70.054 ...70.093

Deviation 0.1

mm

69.954 ...69.993

Deviation 0.25

mm

69.804 ...69.843

Deviation 0.5

mm

69.554 ...69.593

Deviation 0.75

mm

69.304 ...69.343

Deviation 1.0

mm

69.054 ...69.093

BE03.10-N-1002-01B

Basic bore Ø for connecting rod bearing

mm

75.000 ...75.019

BE03.10-N-1004-01B

Permissible deviation of axial parallelism between connecting rod bearing bore and connecting rod bush bore over a length of 50 mm

mm

0.025

BE03.10-N-1005-01B

Permissible out-of-roundness of basic bores

Connecting rod bearing

mm

0,008

Connecting rod bush

mm

0,006

BE03.10-N-1008-01B

Permissible weight difference for connecting rod within an engine

g

40

BE03.10-N-1011-01B

Connecting rod bush inside Ø

mm

42.03 ...42.04

BE03.10-N-1013-01B

Connecting rod bolt

Thread

M

121,25

Shank length (L) when new

mm

56,0

Shank length (L)

mm

57,0

BE03.10-N-1014-01B

Distance between connecting rod bearing seat and connecting rod bush inside Ø

mm

156.510 ...156.445

Number

Designation

Engine
904.9

BE03.20-N-1004-02B

Connecting rod bearing journal Ø

Default

mm

69.995 ...70.015

Deviation -0.1

mm

69.895 ...69.915

Deviation -0.25

mm

69.745 ...69.765

Deviation -0.5

mm

69.495 ...69.515

Deviation -0.75

mm

69.245 ...69.265

Deviation -1.0

mm

68.995 ...69.015

Number

Designation

Engines
900.9, 902.9, 904.9, 906.9

BA03.10-N-1001-01B

Bolt of connecting rod bearing cap to connecting rod

Stage 1

Nm

10

Stage 2

Nm

45

Stage 3

°

90