Repairing/Aligning Connecting Rod
Connecting Rod SpecificationsConnecting Rod Used In Engine 119.96x:
Engine 119.96x
Center Of Conrod Bearing Bore To Center Of Conrod Bush Bore (L): 154.450 - 154.550 mm
Width Of Conrod At Conrod Bearing Bore (B): 24.857 - 24.890 mm
Width Of Conrod At Conrod Bush Bore (b): 27.900 - 28.000 mm
Basic Bore For Conrod Bearing Shells (D): 51.600 - 51.619 mm
Basic Bore For Conrod Bush (d): 29.000 - 29.021 mm
Conrod Bush ID (d1): 26.007 - 26.013 mm
Piston Pin Play In Conrod Bush: 0.007 - 0.013
Peak-to-valley Height Of Conrod Bush On Inside: 0.005
Permissible Twist Of Conrod Bearing Bore Relative To Conrod Bush Bore: 0.15
Permissible Variation Of Parallelism Of Conrod Bearing Bore To Conrod Bush Bore: 0.07
Permissible Variation Of Conrod Bearing Bore From Roughness: 0.01
Permissible Difference In Weight Of Complete Conrod Within An Engine: 4 grams
Connecting Rod Used In Engine 119.97x And 119.98x:
Engines 119.97x and 119.98x
Center Of Conrod Bearing Bore To Center Of Conrod Bush Bore (L): 148.950 - 149.050 mm
Width Of Conrod At Conrod Bearing Bore (B): 24.857 - 24.890 mm
Width Of Conrod At Conrod Bush Bore (b): 21.900 - 22.100 mm
Basic Bore For Conrod Bearing Shells (D): 51.600 - 51.619mm
Basic Bore For Conrod Bush (d): 27.000 - 27.210 mm
Conrod Bush ID (d1): 24.007 - 24.013 mm
Piston Pin Play In Conrod Bush: 0.007 - 0.018
Peak-to-valley Height Of Conrod Bush On Inside: 0.005
Permissible Twist Of Conrod Bearing Bore Relative To Conrod Bush Bore: 0.15
Permissible Variation Of Parallelism Of Conrod Bearing Bore To Conrod Bush Bore: 0.07
Permissible Variation Of Conrod Bearing Bore From Roughness: 0.01
Permissible Difference In Weight Of Complete Conrod Within An Engine: 4 grams
Procedure
NOTE:
- Conrods which have been overheated as a result of the bearing damage (blue discoloring) must not be re-used.
- Conrod and conrod caps are marked together.
- The conrod stem must not have any transverse scoring and notches.
- Conrod are supplied With machined conrod bush as a replacement part.
- Conrod and crankshafts with different thrust collar diameter may be installed together when performing repairs.
- Engine 119.97x The conrod and the conrod cap are fixed together with fit sleeves.
- Pay attention to difference in weight when replacing the conrod.
Connecting Rod Of Engine Type 119.96x Shown:
Legend
1 Weight balance
9 Locating grooves
10 Oil filling
Checking
1. Check conrod bolts, replace if necessary.
2. Engine 119.96: Examine bores for conrod bolts.
- Fit conrod cap onto a conrod bolt.
- If the conrod cap moves down as the result of its own weight, the conrod must be replaced.
3. Install conrod bearing caps.
- Oil thread and bolt head contact surface for this step and tighten to 40 Nm.
4. Measure conrod bearing basic bore.
- If the basic bore exceeds the value of 51.619 mm or is conical, dress bearing cover at its contact surface on a dressing plate up to max. 0.02 mm.
Connecting Rod Used In Engine 119.96x:
5. Press in new conrod bush so that the oil bores are aligned (arrows).
- Insertion pressure 2500 N.
6. Turn or ream conrod bush.
7. Dress side contact surfaces of conrod on the dressing plate.
Aligning
8. Align conrod with conrod tester.
9. Align conrod bearing bore to conrod bush bore (parallelism).
10. Examine twist of conrod bearing bore to conrod bush bore and correct if necessary.