SPECIAL NOTE; This section deals with installing new bearings in the engine cases. Normally, the left main bearing must be first installed on the crankshaft, and then the crank and bearing are put into the left case as a unit. If you are merely reinstalling the original crankshaft, and are sure that its alignment and end play in the engine cases is correct, then proceed normally with the instructions.
Installation of New Bearings and Bushings
If you are not sure of the crankshaft alignment and end play, and you wish to check it, do not install the crankshaft oil seals, do not install the left main bearing on the crankshaft, and do not install the crankshaft or the left main bearing in the left engine case. It will be necessary to install these items at a later point after checking the crankshaft for the proper measurements as outlined in Section 2 of this chapter.
1. Set the crankshaft in a vise fitted with soft faced jaws. Position the left drive shaft pointing directly upward. Locate the shims you removed from behind the left main bearing during disassembly of the engine and put them in place on the drive shaft. Set the new bearing on the drive shaft and push it down as far as you can with your fingers. Locate a short piece of pipe whose inside diameter is large enough to pass over the drive shaft and firmly contact the inner race of the bearing (Fig. 75).
With a hammer, tap on the end of pipe to drive the bearing into place, moving it all the way down until it bottoms on the shims. Be careful not to drive or exert force on the outer race of the bearing, as this could cause subsequent failure.
NOTE: The left main bearing (OSSA Part No. 991-141) is slightly different than the right main bearing (OSSA Part No. 991-140). They are essentially the same bearings, but the internal clearance between the balls and races of the left bearing are greater than in the right. This difference is noted by the letters "C3" either stamped or printed on some part of the left bearing (Fig. 76 and 77). It is not recommended that a bearing without this "C3" marking be installed as a left main bearing.
2. The engine cases must be thoroughly clean, especially the inside
of the bearing inount bosses. Blow the cases dry with compressed air to
remove any solvent or cleaner that may be trapped in remote areas. Check
the bosses for any damage or wear that