With Engine Removed

NOTE: Before the bearing clearance is checked in conjunction with the fitting of new bearings, the crankpin out-of-round and taper must be inspected. Bearing clearance is measured using Plastigage, available in three thicknesses under part no. (45) 30 06 558. Use type PG-1 (green).

Plastigage can be used to measure both bearing clearance and out-of-round.
1. Turn the engine upside down on the stand so that the weight of the crankshaft will not affect the readings.





2. Clean the parts to be measured, making sure that all oil and dirt is removed. Place a strip of Plastigage about 6 mm (0.24 inch) to one side of the center-line of the journal.
3. Fit the bearing cap, tightening to a torque of 20 Nm (15 ft. lbs.) and then tighten through a further quarter-turn (through 90°). The crankshaft must remain absolutely stationary during measuring.
4. Remove the bearing cap. The Plastigage strip should now be adhering either to the bearing shell or crankshaft journal.





5. Measure the width of the Plastigage strip using the scale printed on the package and read off the clearance. One side of the package is calibrated in mm and the other in thousandths of an inch. Measure the strip at its widest point, taking care not to touch it with your fingers.