TUBE AS 1253248 - Caterpillar

Connecting Rod
Use the 2H6782 Connecting Rod Boring Machine to recondition connecting rods and to check for connecting rod distortion. The 5P2009 Rework Group is available for the 2H6782 Connecting Rod Boring Machine. To install the rework group see Special Instruction GMG02394.Press a new piston pin bushing into the connecting rod. Assemble new rod bearings and the expansion sleeve. Tighten rod bolt nuts in the following step sequence.1. Put crankcase oil on bolt threads and seating faces of cap and nut.2. Tighten both nuts to 30 3 lb. ft. (40 4 N m).3. Put a mark on each nut and cap.4. Tighten each nut 60° from the mark.Clean spindle and slide the expansion sleeve and connecting rod into place. Install and tighten nut hand tight.Adjust the carrier to the distance between center of the bores, [center-to-center distance is 7.900 .001 in. (200.66 0.03 mm)]. Position the locating rods .25 in. (6.4 mm) from the connecting rod. Install front bushing in bracket and insert locating arbor through front bushing. Slide the centering sleeve over the end of the locating arbor. Slide the locating arbor through the rear bushing, centering sleeve, and into the connecting rod. Tighten knobs until locating rods lightly contact the connecting rod. Lock the locating rods and carrier.To check connecting rod distortion, slide locating arbor in and out of rear bushing. If the locating arbor does not slide freely, recheck horizontal location. If the locating arbor still binds, loosen the carrier clamp and raise or lower the carrier until the locating arbor slides freely. Read the vernier scale and note the variation from the nominal dimension. If the variation exceeds .010 in. (0.25 mm) the rod is distorted and should be replaced. Mark replacement rods for cylinder identification on bearing tab slot side of rod and cap.With the center-to-center distance set to the nominal dimension, set tool in boring bar and insert the boring bar and front bushing. Connect boring bar to the feed mechanism and engage the feed lever. Install the hand crank or an electric drill and flexible adapter and bore the bushing. Use a slow feed rate. Check the bore size. The size is 1.5010 .0003 in. (48.125 0.008 mm). A 5P2050 Connecting Rod Checking Fixture is available for checking connecting rods. For instructions for the use of the checking fixture see Special Instruction SMHS7366.Install connecting rod into piston with boss on rod on same side as crater in piston crown.
CONNECTING ROD AND PISTONWhen installing connecting rod and piston assemblies, inspect the threads of the rod bolts and nuts for damage. The contact surface of the nuts must be flat and free from damage. Damaged parts must be replaced.