Marine Application Torque Spec MTU 60 series MS25056_03E_pg337-340.pdf

2.24.4 Installation of Camshaft Drive Gear

Special tools Designation / Use Part No. Qty.

Cam Gear Retaining Tool J-35652-B 1 Torque Multiplier (Ratio 1:3 min.) → Tools Catalog 1

Material Designation / Use Part No. Qty.

Engine Assembly Grease Lubriplate® No. 105 Engine Oil International Compound #2 5198563

Spare parts Designation / Use Part No. Qty.

Camshaft Gear Bolt 23524882 1

Install the camshaft drive gear, hub, and thrust plate as follows:

1. Coat the contact surfaces of the hub and camshaft thrust plate with clean engine oil (→ Figure 290).

2. Install the hub to the camshaft thrust plate.

3. Install the key into the keyway on the hub.

4. Apply a thin film of Lubriplate® to the bore of the camshaft gear.

5. Support the hub from the engine side.

Note:

A minimum force of 20 kN (4500 lb) must be obtained when pressing the gear on the hub which can distort camshaft gear if applied off center. Only apply force to the inner hub of the gear when pressing.

6. Align the keyway in the camshaft drive gear with the key in the hub and press the gear, onto the hub until it is firmly seated against the shoulder.

Figure 290: Cross-Section of Camshaft Drive and Related Parts

1 Drive Gear, Camshaft 2 Groove, O-Ring 3 Groove, Seal 4 Dowel Hole, Camshaft 5 Thrust Plate, Camshaft 6 Woodruff Key 7 Hub, Camshaft Drive Gear

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Testing of Camshaft Drive Gear Assembly Run-out

1. While supporting the camshaft thrust plate on blocks, position the camshaft drive gear assembly with the engine side facing down.

2. Assemble a dial indicator and magnetic base with the indicator stem resting on the face of the camshaft drive gear, just inboard of the drive gear teeth. Zero the dial indicator.

3. Rotate the drive gear two full rotations while reading the total indicated run-out.

Note:

The sum of the maximum amount the dial indicator needle moves to the left and right of zero, gives the total indicated run-out, or Total Indicator Reading (TIR).

3.1 If the measured value is 0.114 mm (0.0045 in.) or less, then the drive gear assembly can be reused.

3.2 If the measured value is more than 0.114 mm (0.0045 in.), the drive gear assembly parts must be replaced.

Installation of Camshaft Drive Gear – Continued

1. Coat the camshaft thrust plate O-ring with clean engine oil.

2. Install it into its groove in the camshaft thrust plate.

3. Install a new diamond seal in the camshaft thrust plate groove by pressing it in with the rounded end of the seal extractor or the flat end of a ruler.

4. Be sure the O-ring sealing surface of the gear case is clean and free of burrs.

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5. Install the hub and camshaft thrust plate to the open‐ ing in the gear case. The depression in the rear face of the camshaft thrust plate must be positioned at 12 o'clock, (→ Figure 291), to align the retaining bolts in the thrust plate with those in the head and Number 1 camshaft cap.

6. Using a fiber mallet or plastic hammer, tap the cam‐ shaft drive gear at 90 degree intervals toward the engine, until the thrust plate bolts can be started in the cylinder head and Number 1 camshaft cap.

Note:

Make sure camshaft dowel hole in camshaft drive hub is aligned with camshaft dowel before tightening thrust plate bolts. A misaligned hub can damage the camshaft and thrust plate components. Use care when installing the camshaft thrust plate retaining bolts to prevent accidentally dropping them into the gear case and causing damage to gear train.

7. Using a 13 mm socket and ratchet, tighten the thrust plate bolts alternately and evenly to draw the thrust plate straight into the gear case. Torque the bolts to 30 to 38 Nm (22 to 28 lbft).

8. Install the gear case cover (→ Page 181).

Note:

Always hold the camshaft drive gear stationary using camshaft drive gear retaining tool (J-35652-B) to pre‐ vent component damage, while loosening or tighten‐ ing the camshaft drive gear-to-camshaft bolt. Before installing the camshaft drive gear access cover, it will be necessary to install and tighten the camshaft drive gear retaining bolt, and to measure and adjust the adjustable gear-to-camshaft drive gear lash.

9. Install retaining tool (J-35652-B) and tighten the new Camshaft Gear Bolt as follows:

9.1 Apply a small amount of INTERNATIONAL

COMPOUND #2, or equivalent, to the bolt threads and underside of the bolt head.

9.2 Install the bolt through the hub and thread into

the camshaft.

Note:

This step will fully seat the cam gear hub to the camshaft and align any of the fine threads on the cam gear bolt that may have been damaged by handling.

9.3 Torque bolt to 200 Nm (175 lbft), back off the

bolt and torque to 75 Nm (55 lbft).

Figure 291: Camshaft Thrust Plate and Dowel Pin Loca‐ tion

1 Camshaft Dowel 2 Dimple 3 Camshaft Dowel Hole

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Note:

Failure to tighten the camshaft hub retaining bolt to the required angle may result in the bolt loosening during engine operation. This may lead to camshaft alignment pin damage, altered engine timing, erratic engine operation, or catastrophic engine failure.

10. Turn the bolt an additional 120 to 150 degrees (→ Figure 292).

Note:

To prevent the cam gear from slipping, it is imperative that the bolt is turned as close to an additional 150 degrees as possible. Use of the Torque Multiplier (Ratio 1:3 min.) can help reduce the effort required to obtain the desired 150 degree rotation.

11. Check the gear train timing and adjustable idler gear‑to‑camshaft drive gear lash (→ Page 281).

12. Install the camshaft drive gear access cover (→ Page 181).

13. Install any components that were removed for access to the gear case cover.

14. Check the lubricating oil level.

15. Check the coolant level.

16. Follow "Engine Run-In Instructions" (→ Page 678).

Figure 292: Torque Turn Limits

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