Usage:
Tight fit between connecting rod eye and piston pin bearing ... .002 to .004 in.(0.05 to 0.10 mm)
NOTE: Connecting rod must be heated for installation of piston pin bearing. Do not use a torch.
Heat connecting rod to temperature of ... 350 to 500° F(177 to 260° C)
Position of pin bearing:
Type A (Narrow Taper) - Bearing junction and locating hole are 180° apart (directly across from each other). Bearing junction and locating hole must be assembled within either area "A" (90 ± 10° from centerline through the connecting rod bores) as shown.
Type B (Wide Taper) - Bearing junction and locating hole are 155° apart (not directly across from each other). Bearing junction and locating hole must be assembled in the top half of connecting rod eye (12.5 ± 1° above the horizontal centerline) as shown.
Make reference to Special Instruction Form No. SMHS7295 for use of pin bearing removal and installation tools and procedures.
(2) Bore in connecting rod for bearing with nuts tight to specifications (6) ... 4.0748 ± .0005 in.(103.500 ± 0.013 mm)
(3) Distance between center of bearings ... 10.300 ±.002 in.(261.62 ± 0.05 mm)
(4) Bore in bearing for piston pin (new) ... 2.0012 ±.0003 in.(50.830 ± 0.008 mm)
Diameter of piston pin (new) ... 1.9998 ±.0002 in.(50.795 ± 0.005 mm)
Maximum permissible clearance between bearing and piston pin (worn) ... .003 in.(0.08 mm)
(5) Bore in bearing for crankshaft ... 3.8236 to 3.8258 in.(97.119 to 97.175 mm)
Clearance between bearing and crankshaft (new) ... .0028 to .0066 in. (0.071 to 0.168 mm)
Maximum permissible clearance between bearing and crankshaft (worn) ... .010 in.(0.25 mm)
NOTE: Bearings are available in .025 in. (0.64 mm) and .050 in. (1.27 mm) smaller than original size.
(6) Tighten procedure for connecting rod bolts:
a. Put 2P2506 Thread Lubricant on bolt threads and contact surfaces of nut and cap.
b. Tighten both nuts to ... 60 ± 6 lb. ft.(80 ± 8 N·m)
c. Put a mark on each nut and end of bolt as shown.
d. Tighten each nut from mark ... 120 ± 5°
NOTE: The connecting rod must be installed so the chamfer on the edge of bore (5) is near the corner on the crankshaft. The side opposite the chamfered edge must be against the other connecting rod on the same crankshaft pin.
Side clearance between two connection rods on same crankshaft pin (new) ... .011 to .033 in.(0.28 to 0.84 mm)
Make reference to Special Instruction Form Nos. GMG02394 & SMHS7366 for information to check and recondition connecting rods.
POSITIONING PIN BEARING (Type A)
POSITIONING PIN BEARING (Type B)
MARKS FOR TIGHTENING CONNECTING ROD BOLTS