3408 Marine Engines
An article "Extended Shafts Now Available For Front Power Takeoff Units" on Pages 5 and 6 of the January 21, 1980 Service Magazine gave information about extended shafts for use with front power takeoff units on 3408 Marine Engines. These shafts are used with "outboard" bearings which must be in correct alignment with the shaft and the engine. Since the outboard bearing is mounted (installed) separately, any movement of the engine will not only destroy the alignment, but will also cause stress on the shaft. For this reason, the outboard bearing must be removed any time it becomes necessary to move the engine. For example, if the engine must be lifted during service work on the marine gear, remove the outboard bearing first. Failure to do this can cause a bent shaft or other possible damage. After the service work is finished and the engine is fastened in place, the outboard bearing must be installed again. Use the same procedure to check and adjust bearing alignment that was used during the original installation. This procedure is given in Special Instruction Form SMHS7684.