Crankshaft Overview
WARNING: This page is about a different variant/trim than selected.
NOTE:
For assembly work, secure the engine on the engine and transmission holder. Refer to ENGINE, SECURING TO ENGINE AND TRANSMISSION HOLDER .
If large quantities of metal particles or abraded material are detected during engine repairs, it may mean the crankshaft or rod bearings are damaged. To prevent subsequent damage, the following work must be performed after the repair: Oil channels must be cleaned carefully; replace oil spray jets, oil cooler and oil filter.
- Bolt
- Replace
- 65 Nm plus an additional 90° turn
- Bearing Cap
- Bearing cap 1: Belt pulley side
- Installed position: Bearing shell retaining tabs in cylinder block and in bearing cap must align
- Bolt
- Replace
- 10 Nm plus an additional 90° turn
- Replace sensor wheel every time bolts are loosened, refer to Fig 2
- Needle Bearing
- Only for vehicles with S-Tronic transmission
- Pulling out and driving in, refer to NEEDLE BEARING ON CRANKSHAFT
- Sensor Wheel
- For the engine speed sensor -G28-
- Replace sensor wheel every time bolts are loosened
- Removing and installing, refer to Fig 2
- Assembly is only possible in one position because of the offset holes
- Crankshaft
- Do not lay on the sensor wheel -5- after removing
- Measuring axial play, refer to CRANKSHAFT, MEASURING AXIAL PLAY
- Radial clearance, measuring, refer to CRANKSHAFT, MEASURING RADIAL PLAY
- Crankshaft dimensions, refer to CRANKSHAFT DIMENSIONS
- Thrust Washers
- For bearing 3
- Bearing Shell
- For cylinder block with oil groove
- Mark used bearing shells for reinstallation but not on the running surface
- Replace bearing shells that have worn down to the nickel layer
- Insert new bearing shells for cylinder block with proper color marking, refer to Fig 3
- Drive Sprocket
- For the oil pump drive chain
- Removing and installing, refer to DRIVE CHAIN
- Bearing Shell
- For bearing cap without oil groove
- Mark used bearing shells for reinstallation but not on the running surface
- Replace bearing shells that have worn down to the nickel layer
- Install the new bearing shells for the bearing cap with the correct color identification, refer to Fig 4
CAUTION:
Danger if the sensor wheel is loose.
- After loosening the bolts -1-, the sensor wheel -2- must always be replaced.
- After tightening a second time, the attachment point of the countersunk bolts of the sensor wheel are so deformed that the bolt heads lie on the crankshaft -3- -arrows- and the sensor wheel is loose underneath the bolts.
NOTE:
The sensor wheel can be installed in only one position because the holes are offset.
Fig 3: Identification Of Crankshaft Bearing Shells For Cylinder Block (Gradual Introduction) - Engine Codes AEG, AVH, AZG, BEV
- The upper bearing shells with the correct thickness are allocated to the cylinder block in the factory. Colored dots on sides of bearing shells serve for identifying bearing shell thickness.
- The letters marked on the lower sealing surface of the cylinder block identify which bearing thickness must be installed in which location.
| Letter on Cylinder Block | Color of Bearing | |
|---|---|---|
| S | = | Black |
| R | = | Red |
| G | = | Yellow |
NOTE:
-Arrow- points in direction of travel.
- Bearing shells with correct thickness are allocated to bearing cap at factory. Colored dots on sides of bearing shells serve for identifying bearing shell thickness.
- The allocation of the bearing shells for the bearing cover is identified by a series of letters on the crankshaft ribbed belt sprocket flange. The first letter of the row of letters represents bearing "1", the second letter is for bearing "2", etc.
| Letter on Crankshaft | Color of Bearing | |
|---|---|---|
| R | = | Red |
| G | = | Yellow |
| B | = | Blue |
| W | = | White |