182 F3B ENGINE T RAKKER E URO 4/5 Preliminary measurement of data to select main bearing and big end bearing shells For each of the journals of the crankshaft, it is necessary to carry out the following operations: MAIN JOURNALS: - Determine the class of diameter of the seat in the CRANKPINS: - Determine the class of diameter of the seat in the crankcase. connecting rod. - Determine the class of diameter of the main journal. - Determine the class of diameter of the crankpin. - Select the class of the bearing shells to mount. - Select the class of the bearing shells to mount.
DEFINING THE CLASS OF DIAMETER OF THE SEATS FOR BEARING SHELLS ON THE CRANKCASE On the front of the crankcase two set s of numbers are marked in the position shown. - The first set of digits (four) is the coupling number of the crankcase with its base. - The second set of digits (seven) is the class of diameter of each of the seats referred to. - Each of these digits may be 1 , 2 or 3 . Figure 87 MAIN BEARING HOUSING NOMINAL CLASS DIAMETER 106.300 to 106.309 106.310 to 106.319 106.320 to 106.330 47535 Base q November2006 Print 603.93.641