Timing Cover: Service and Repair
Fig. 35 Front Case, Oil Pump & Silent Shaft Assembly.:
DISASSEMBLY
Disassemble front case, oil pump and silent shaft in numbered sequence noting the following:
1. Use oil pressure switch socket No. MD998054 or equivalent to remove oil pressure switch.
2. Remove oil pan, refer to Oil Pan Replacement under Engine Lubrication/Service and Repair.
3. Use plug cap socket No. MD998162 or equivalent to remove front case plug cap (17).
Fig. 36 Blocking Silent Shaft For Oil Pump Sprocket Removal:
4. When removing oil pump driven gear bolt, insert a Phillips screwdriver into plug hole, to block the silent shaft.
Fig. 30 Removing Silent Shaft Front Bearings.:
5. Using silent shaft bearing puller No. MD998371 or equivalent, remove silent shaft front bearing as shown.
Fig. 31 Removing Silent Shaft Rear Bearing.:
6. Using silent shaft bearing puller No. MD998372 or equivalent, remove right silent shaft rear bearing as shown.
Fig. 37 Removing Left Silent Shaft Rear Bearing.:
7. Using silent shaft bearing puller No. MD998374 or equivalent, remove left silent shaft rear bearing as shown.
INSPECTION
1. Inspect front case for the following:
a. Clogged oil passages.
b. Damaged or seized left silent shaft front bearing section.
c. Cracks or other signs of damage on case.
2. Inspect oil seal lip for wear or damage, replacing as necessary.
3. Test oil switch as follows:
a. Connect an ohmmeter between switch terminal and switch body.
b. If ohmmeter reads no continuity, replace switch. If ohmmeter reads continuity, proceed to step c.
c. Insert a fine wedge into oil switch hole. Ohmmeter should read no continuity when wedge is slightly pressed into hole, If ohmmeter reads continuity, replace switch.
4. On models with turbocharged engine, inspect oil cooler bypass valve as follows:
a. Ensure valves move smoothly.
Fig. 38 Oil Cooler Bypass Valve.:
b. Measure dimension L on bypass valve. At room temperature, dimension L should be 1.358 inch.
c. Dip valve in engine oil heated to 212°F. Dimension L should now be at least 1.570 inch.
5. On all models, inspect oil pump as follows:
a. Install oil pump gears in front case and rotate gears, ensuring smooth rotation without excessive looseness.
b. Check for for ridge wear on surface of oil pump cover.
c. Check drive gear and driven gear tip clearance.
d. Check side clearance of gears.
6. Inspect silent shaft for the following:
a. Clogged oil passages.
b. Seized or damaged journal.
c. Ensure oil clearance is within specifications. Clearance should be as follows:
Right Front, 0.0008 - 0.0024 inch;
Right Rear, 0.0008 - 0.0021 inch;
Left Front, 0.0002 - 0.0036 inch;
Left Rear, 0.0017 - 0.0033 inch.
7. Inspect oil jet and check valve for clogging or damage.
ASSEMBLY
Reverse removal procedure to install, noting the following:
1. When installing oil jet, ensure nozzle is installed toward the piston.
Fig. 39 Installing Left Silent Shaft Rear Bearing.:
2. When installing left silent shaft rear bearing, apply clean engine oil to engine block bearing hole and to outer circumference of bearing. Using bearing installation tool No. MD998374 or equivalent, install bearing into cylinder block.
Fig. 40 Installing Right Silent Shaft Rear Bearing.:
3. When installing right silent shaft rear bearing, apply clean engine oil to engine block bearing hole and to outer circumference of bearing. Using bearing installation tool No. MD998373 or equivalent, install bearing into cylinder block. Ensure oil hole in bearing is aligned with oil hole in cylinder block.
Fig. 41 Installing Silent Shaft Front Bearing.:
4. When installing silent shaft front bearing, apply clean engine oil to engine block bearing hole and to outer circumference of bearing. Using bearing installation tool No. MD998373 or equivalent, install bearing into cylinder block. Ensure oil hole in bearing is aligned with oil hole in cylinder block.
5. When installing oil pump gears, coat gears with clean engine oil, then align mark on drive gear notch with mark on driven gear tooth.
6. Install crankshaft oil seal using oil seal installation tool No. MD998375 or equivalent.
7. Install oil seal (22) and silent shaft oil seal (23) by placing a socket over the top of the seal and pressing it into the case.
Fig. 42 Front Case Attaching Bolts.:
8. Install front case as follows:
a. Place crankshaft front oil seal guide No. MD998285 or equivalent over front end of crankshaft, then apply engine oil to outer circumference of guide.
b. Install front case over top of guide, onto cylinder block. Temporarily tighten all bolts except the filter bracket attaching bolts, referring to bolt length chart.
c. Install oil filter bracket and the four attaching bolts.
d. Tighten all bolts to specifications.
9. When installing driven gear bolt (19), insert a Phillips screwdriver into plug hole on left side of cylinder block, to block the silent shaft.
10. When installing plug cap, place a new O-ring into groove of case, then use plug cap socket No. MD998162 or equivalent to tighten cap.
11. Install oil pan, refer to Oil Pan Replacement under d12. When installing oil pressure switch, coat threads of switch with gasket adhesive. Do not allow hole in end of switch to be covered with adhesive. Install switch using oil pressure switch socket No. MD998054 or equivalent.