FUSO 4M4 – Engine – CRANKSHAFT AND CRANKCASE – Installation procedure

Installation: Crankshaft gear
• Heat the crankshaft gear to approximately 170 ± 10°C with a gas burner or the like.

• Align the key fitted in the crankshaft with the slot in the crankshaft gear. Drive the gear into position by lightly striking its end face with a plastic hammer.

Installation: Thrust plates
• Install the thrust plates on the rearmost main bearings with the oil grooves on the inner plates facing inward and those on the outer plates outward as shown in the illustration.

• Use oversized thrust plates when adjusting the crankshaft end play. The upper and lower thrust plates on the same side must be of the same size. The thrust plates on one side may differ in size from those on the other side.

Installation: Main bearings

• Select and use a main bearing set of a thickness that can accommodate the inside diameter of each main bearing fitting hole between the upper crankcase and lower crankcase and the diameter of the corresponding crankshaft journal.
Select the appropriate main bearing set by one of the following two methods.

(1) Measurement based selection
• Mount the lower crankcase on the upper crankcase without fitting main bearings.
• Tighten the main cap bolts to 20 N·m {2.0 kgf·m}.
• Measure the inside diameter of the main bearing fitting hole between the upper crankcase and lower crankcase (vertically from one point), and the diameter of the crankshaft journal (vertically or horizontally from two points).

• Select a main bearing set that matches the measurements from the table below.
If the color identification mark is indiscernible, measure the thickness of the bearing walls and use the measurements in its place.

(2) Color identification mark based selection
•Use selection by identification color for new parts.
• The crankshaft, upper crankcase, and main bearing can be appropriately combined in the following ways according to their color identification marks:
1J: Position of color identification mark on No. 1 journal
2J: Position of color identification mark on No. 2 journal
3J: Position of color identification mark on No. 3 journal
4J: Position of color identification mark on No. 4 journal
5J: Position of color identification mark on No. 5 journal

Installation: Lower crankcase

• Clean the sealant application surfaces of each part.
• Apply a bead of sealant to the upper crankcase evenly and without any breaks as shown in the illustration.
• Install the lower crankcase within three minutes of applying the sealant to the upper crankcase, being careful not to dislodge the sealant.

• Apply engine oil to the threads and seating surface under the head of each of the main cap bolts, and tighten the bolts to a torque of 20 N·m {2.0 kgf·m} in the order indicated in the illustration (1 to 10).
• Then, tighten the main cap bolts further by 90° in the same order.
• Tighten them by another 90° in the same order.
• After completing tightening of the main cap bolts, tighten the bolts (11 to 26) to the specified torque in the order indicated in the illustration.

• After tightening the main cap bolts using the torque-turn tightening method, make a punch mark on the head of each main cap bolt to indicate the number of times it has been used.

• After installing the lower crankcase, check that the crankshaft can be rotated lightly by hand. Inspect the main bearing cap fitting holes if the crankshaft does not rotate smoothly.

•Installation: Rear oil seal
Install the rear oil seal in the rear oil seal case in the illustrated direction until the end surface of the oil seal is flush with the end surface of the rear oil seal case.

Installation: Rear oil seal case
• Apply engine oil to the rear oil seal lip.
• Clean the sealant application surface.
• Apply a bead of sealant to the rear oil seal case evenly and without any breaks as shown in the illustration.
• Install the rear oil seal case on the crankcase assembly within three minutes of applying the sealant, being careful not to dislodge the sealant.

Installation: Front plate
• Clean the sealant application surfaces of each part.
• Apply a bead of sealant to the upper crankcase and lower crankcase evenly and without any breaks as shown in the illustration.
• Install the front plate within three minutes of applying the sealant, being careful not to dislodge the sealant.

 

 

Leave a Reply

Your email address will not be published. Required fields are marked *