LEVER AS 2255625 - Caterpillar

Remove And Install Crankshaft Main Bearings
START BY:a) remove oil pump 1. Check each main bearing cap (2) for its location on the engine. Each cap has an arrow (1) which points to the front of the block and a number (3) which gives the location of that cap.2. On the 3408 Generator Sets, remove No. 2 through No. 4 main bearing caps from the engine. On the 3412 Generator Sets, remove No. 2 through No. 6 main bearing caps from the engine. Remove the lower bearings from the caps.3. Remove the thrust plates from each side of the No. 3 main bearing on the 3408 Generator Sets and from the No. 4 main bearing on the 3412 Generator Sets.
If the crankshaft is turned in the wrong direction, the tab of the bearing will be pushed between the crankshaft and the cylinder block. This will cause damage to the crankshaft and block.
4. Turn the crankshaft until tool (A) can be installed in oil hole (4). Turn the crankshaft in the direction which will push the upper main bearing out, tab end first.
Make sure the upper and lower halves of bearings are installed so bearing tabs (5) fit into the notch in cylinder block and bearing caps.
Do not put oil on parts until the bearing clearance has been checked.5. Use tool (A) to install the upper bearings in the block. Make sure that the end of the bearing without the tab goes into the engine block first.6. Install the lower bearings in the bearing cap. When the bearing clearance is checked and the engine is in a vertical position, the crankshaft will have to be lifted up and held against the upper halves of the main bearings to get a correct measurement with Plastigage (B). The Plastigage will not hold the weight of the crankshaft and give a correct indication. If the engine is in a horizontal position, it is not necessary to hold the crankshaft up. Do not turn the crankshaft when the Plastigage is in position to check clearances.7. Check the bearing clearance with Plastigage (B) as follows:a) Put a piece of the Plastigage on the surface of the lower bearing half. b) Install the main bearing caps with arrow (6) toward the front of the cylinder block. Each cap has a number (7) on the bottom surface and must be installed in the same position as the correct number on the left side of the cylinder block.c) Put clean oil on the threads of the cap bolts. Install the cap bolts finger tight.d) Tighten the bolts on the tab end of the caps first to a torque of 258 14 N m (190 10 lb.ft.).e) Tighten the bolts on the other end of the caps to a torque of 258 14 N m (190 10 lb.ft.).
Do not use an impact wrench to tighten the bolts the addiational 120°.
f) Put a mark across the bolt head and cap. Tighten the bolts opposite the tab