The flywheel is attached to the rear end of the crankshaft with twelve bolts. The bolt holes in the crankshaft and flywheel are equally spaced. The flywheel is not indexed to the crankshaft, and may be installed in any position. A scuff plate is used between the flywheel and the bolt heads to prevent the bolt heads from scoring the flywheel surface. See Figure
1. Bolt (12)
4. Flywheel Housing
2. Scuff Plate
6. Ring Gear
Typical Flywheel Assembly
A steel ring gear, which meshes with the starting motor pinion, is shrunk onto the rim of the flywheel. Refer to Section
The flywheel is machined to provide true alignment with the clutch. The clutch plate, if used, is bolted to the flywheel with 3/8 in.-16 bolts.
The flywheel must be removed for service operations such as replacing the starter ring gear, crankshaft oil seal, crankshaft or the flywheel housing.
Repair or Replacement of Flywheel
To determine if repair is possible or replacement is necessary, perform the following procedure. See Figure
Flowchart for Repair or Replacement of Flywheel
Cleaning and Removal of Flywheel
Precleaning is not necessary.
Remove the flywheel as follows:
Remove the inspection plug in the bottom of the flywheel housing.
Loosen, but do not remove the last flywheel attaching bolt.
Remove the flywheel lock.
To avoid injury from a falling flywheel when removing the last bolt, hold the flywheel against the crankshaft by hand to prevent it from slipping off the crankshaft. The flywheel is not doweled to the crankshaft.
Remove the last flywheel attaching bolt and scuff plate.
Inspection of Flywheel
Inspect the flywheel as follows:
Inspect the clutch contact base of the flywheel.
Check clutch contact base for scoring, wear, or cracks.
If clutch contact face is scored or worn, the flywheel may be refaced.
If clutch contact face is cracked, the flywheel must be replaced.
Do not remove more than 0.508 mm (0.020 in.) material from the flywheel. Maintain all of the radii when resurfacing.
Inspect the ring gear.
Check ring gear for excessively worn or damaged gear teeth.
Apply International Compound #2 (or equivalent) to the threads and to the bolt head contact area (underside) of the remaining bolts. The bolt threads must be completely filled with International Compound #2 (or equivalent). Any excess must be wiped off. See Figure
Flywheel Bolt Preparation
International Compound #2 or equivalent must never be used between two surfaces where maximum friction is desired, as between the crankshaft and the flywheel.
Install the bolts and torque them to 75 Nm (55 lbft).
Turn the bolts an additional 60 degrees, or 1flat on a six-point bolt. See Figure
Install the pipe plug and torque to 45-56 Nm (33-41 lbft).
Mount a dial indicator with a magnetic base on the flywheel housing. See Figure
Check the run-out of the flywheel at the clutch contact face.
Measuring Flywheel Runout
The maximum allowable run-out is 0.025 mm (0.001 in.) total indicator reading per inch of radius (or 0.001 mm per millimeter of radius). The radius is measured from the center of the flywheel to the outer edge of the clutch contact face of the flywheel. Example: A 14 in. clutch would allow 0.175 mm (0.007 in.) total indicator reading.
If maximum total indicator reading exceeds, 0.025 mm (0.001 in.) per inch of radius, it may be necessary to repeat the assembly procedure until the cause can be detected and eliminated.