N14 Base Engine Troubleshooting and Repair Manual – 001-013   Camshaft Gear (Camshaft Removed)

Remove the camshaft. Refer to Procedure 001-008.

CAUTION  Place a wooden block under the camshaft to avoid damage as the camshaft drops free from the cam gear.

Install the camshaft and gear assembly into a hydraulic press. Place V-blocks under the gear. Make sure the V-blocks support the hub area of the gear.

NOTE: Do not use a heating torch to remove the gear. If you use a heating torch, a new gear must be installed.

Push the shaft from the gear.

NOTE: If the camshaft key is marked with an arrow, record the direction in which it is pointed.

Use a flat chisel and hammer to remove the camshaft key.

CAUTION  If the inside diameter of the gear is damaged or has fretting in excess of a 3.175 mm [0.125 in] wide band, do not use the gear. Fretting or other damage can result in gear movement on the camshaft nose, which can cause camshaft nose failure.

Inspect the camshaft gear for cracks, chipped, or broken teeth.

Scratches must not exceed 0.79 mm [0.031 in] depth, and must be at least 3.2 mm [0.125 in] apart.

Inspect the bore of the gear for fretting or burrs.

NOTE: If the fretting, burrs, or raised material can not be removed with a fine crocus cloth, replace the gear.

Inspect the gear keyway for burrs.

Remove burrs with a fine crocus cloth.

NOTE: If the keyway is damaged or the burrs can not be removed with a fine crocus cloth, the gear must be replaced.

Measure the inside diameter of the gear bore.

Replace the camshaft gear if it does not meet specifications.

CAUTION  If the area of fretting is wider than a 3.175 mm [0.125 in] wide longitudinal band, do not use the camshaft. Fretting or other damage can result in gear movement on the camshaft nose and can cause a camshaft nose failure.

Inspect the camshaft nose in the gear fit area for fretting or burrs.

NOTE: If fretting, burrs, or other raised material can not be removed with a fine crocus cloth, replace the camshaft.

Measure the outside diameter of the camshaft nose in the gear press fit area.

Replace the camshaft if it does not meet specifications.

Use a plastic mallet to install the camshaft gear key.

NOTE: If the same camshaft and gear are used again, use the same part number key as the one that was removed. Make sure the arrow on the key is pointing in the same direction as when it was removed.

See the engine dataplate and the Control Parts List Manual, Bulletin Number 3379133, for the correct key part number and key orientation.

Put the camshaft in a vertical position with the gear fit area (nose) pointing up.

Wipe off the gear fit area to remove any grease or oil before installing the gear.

CAUTION  Wear protective gloves when handling parts that have been heated to prevent personal injury.

Heat the gear in an oven at 191°C to 204°C [375°F to 400°F] for 1 to 4 hours. Do not heat the gear in an oven for more than 4 hours.

Remove the gear from the oven.

NOTE: Install the gear on the camshaft within 30 seconds after it is removed from the oven.

Align the gear keyway with the key in the camshaft, and install the gear. The timing marks and the gear part number must be facing away from the camshaft.

NOTE: Keep the camshaft in a vertical position with the gear up until the gear has cooled.

If the gear does not seat against the locating shoulder on the camshaft, remove the gear and install it again. Make sure to inspect the camshaft again each time the gear is removed.

Use a feeler gauge to check the clearance between the camshaft gear and the shoulder. The clearance must not exceed 0.13 mm [0.005 in].

Install the camshaft. Refer to Procedure 001-008.

Install the gear cover and related components. Refer to Procedure 001-031.

Install the cam follower assemblies. Refer to Procedure 004-001.

Check the engine timing. Refer to Procedure 006-025.