R8 Quattro Coupe V10-5.2L (BUJ) (2010)
Crankshaft Main Bearing: Service and Repair
Main Bearing Shells, Used and Reworked Crankshafts, Allocating
Main Bearing Shells, Used and Reworked Crankshafts, Allocating
Allocation of Crankshaft Bearing Shells for Cylinder Block
‹› Bearing shells are allocated to cylinder block corresponding to color markings stamped into cylinder block.
‹› With used and reworked crankshafts, the main crankshaft journals must be measured to allocate the appropriate bearing shells.
‹› Crankshaft dimensions, refer to => [ Crankshaft Dimensions ] See: Crankshaft/Specifications.
‹› Thicker over-sized bearing shells are available for reworked crankshafts. These have the same color markings as the original-size bearing shells.
‹› The bearing identification refers to the first installation during production: R = red, G = yellow, B = blue.
‹› During a second installation by service, the next thinner bearing shell is installed, for example, black instead of red, as shown in the following
table:
‹› This procedure takes into the account the cylinder block shrinkage.
‹› Even if the guide frame was only loosened, the requirement applies to the second installation.
Allocation of Crankshaft Bearing Shells for Guide Frame
‹› With used and reworked crankshafts, the main crankshaft journals must be measured to allocate the appropriate bearing shells.
‹› Any other markings on the crankshaft are invalid when reworking crankshafts.
‹› Allocate bearing shells to the diameter of the main crankshaft journals using the following table