5-101.bk Page 11 Friday, March 17, 2006 11:05 AM All new service replacement crankshafts, short blocks or basic engines will have a dowel pin in the crankshaft rear flange. In nearly all cases, the flywheel will already have a hole in it to accept the dowel pin. If, in an earlier version, the flywheel or torque converter drive flange does not have a hole in it for a dowel pin, it must be reworked. Crankshafts used in early mechanically governed engines, part No. 4566C5127M, did not have a dowel pin or dowel pin hole. It is acceptable to use this early non-pinned crankshaft design in any mechanically governed engine, even when the original installation may have had dowel pins.
DOWEL PIN REMOVAL If it is necessary to rework the flywheel or torque converter drive flange, two holes must be added using a 19/32-inch drill bit. One hole is for the dowel pin, and another directly opposite the first hole is to maintain balance of the flywheel/torque converter drive flange. To remove rear crankshaft dowel pin: 1. Using vise grips, securely grip dowel pin. 2. Rotate dowel pin back and forth while exerting outward pressure until pin is removed. Refer to Figure 5-7. DOWEL PIN INSTALLATION 2" x .651" Refer to Figure 5-8. 4" x 2.165" To install a replacement crankshaft dowel pin: 1. Position dowel pin in a 0.5562-inch (14.1275 mm) diameter unthreaded hole in rear of crankshaft.
The pin must be installed with the flat surface aligned parallel to the center of crankshaft, as shown in Figure 5-8. 2" x 2.500" 4" x 1.250" 2. Use a suitable tool to drive the pin into the hole. The pin must be firmly seated and protrude 0.77 inch (19.56 mm) from the crankshaft. .594" HOLE .594" HOLE 5.000" BASE CIRCLE 2" x 2.500" 200651a Figure 5-7 — Dowel Pin Hole Dimensions (Flywheel or Torque Converter Drive Flange) 200337a Figure 5-8 — Dowel Pin Alignment Page 5-11 200 BENCH PROCEDURES