1. Modern Automotive Technology PowerPoint for by Russell Krick
Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois

2. Chapter 52
Engine Front End
Service and Engine
Installation

3. Contents Timing chain service Timing gear service
Crankshaft front seal service
Engine front cover service
Timing belt service
Complete engine assembly
Installing the engine
Engine break-in

4. Timing Chain Service
Timing chains can be used on both push rod and overhead cam engines
Inspect the chain for looseness
Check the crankshaft key and camshaft dowel for wear or damage
If used, check the chain tensioner and guides for wear

5. V-type, diesel engine with a timing chain
Front End Assembly
V-type, diesel engine with a timing chain

6. OHC Timing Chain
Uses a tensioner to compensate for chain wear or stretch
Chain guides prevent vibration, or slap
Fiber or plastic facings on guides and tensioner may wear

7. OHC Timing Chain

8. Installing Timing Chain
Align the marks on the sprockets to time the crankshaft with the camshaft

9. Installing Timing Chain
Install the oil slinger after the sprocket
It sprays oil on the chain and sprockets

10. Installing Timing Chain
When installing complex OHC timing chains, double- check everything

11. Timing Gear Service
Timing gears are normally more dependable than timing chains
However, gear teeth can wear or become chipped and damaged
Replace gears as a set, if needed

12. Measuring Backlash
Backlash is the amount of clearance between the timing gear teeth
To measure:
install a dial indicator with the stem on a cam gear tooth
wiggle the camshaft, while watching the indicator
the needle movement equals the backlash
Replace the timing gears if the backlash is greater than specs

13. Measuring Backlash (Dial Indicator and Feeler Gauge)
The largest feeler gauge that fits in the teeth indicates clearance

14. Replacing Timing Gears
Gears may be press-fit on the crankshaft and camshaft
A puller is normally needed to remove the crankshaft gear
Gears can often be installed with light blows from a brass hammer

15. Replacing Timing Gears
Some camshaft gears must be pressed on and off after removal from the engine

16. Timing marks on a diesel engine
Timing Gear Alignment
Timing marks on a diesel engine

17. Measuring Gear Runout Runout is unwanted gear wobble, or side movement
To measure:
install a dial indicator with the stem on the outer edge of the cam gear
turn the crankshaft while noting the indicator readings
the needle movement equals the runout

18. If the runout is beyond specs, check the cause
Measuring Gear Runout
If the runout is beyond specs, check the cause

19. Crankshaft Front Seal Service
Replace the front seal whenever it is leaking or anytime the front cover is removed
Seal replacement usually requires the removal of the radiator, other accessory units, and the crankshaft damper

20. Removing Crankshaft Damper

21. A special puller is often used
Removing the Old Seal
A special puller is often used

22. Installing the New Seal
Before installing, oil the lip and coat the outside with nonhardening sealer

23. Engine Front Cover Service
Front covers are usually made of thin sheet metal or cast aluminum
Make sure a sheet metal cover is not warped

24. Typical parts included
Front Cover Gasket Set
Typical parts included

25. Installing the Gasket
Coat the cover flange or gasket with an approved adhesive-sealer to hold it in place

26. Using Silicone Sealer Apply sealer in the specified thickness
Surround the bolt holes and water passages

27. Removing Old Gaskets
If you are servicing the front cover only, cut off the old gasket and clean the surfaces

28. Surface Preparations
Extra silicone sealer is recommended where the front cover meets the oil pan
A small piece of pan gasket can be placed on the protruding oil pan flange

29. Installing the Front Cover
Carefully fit the front cover into place without disturbing the gasket or silicone sealer
With some designs, you must loosen the oil pan bolts and partially drop the pan

30. Installing the Front Cover
An alignment tool may be used
Remove the tool after installation

31. Front Cover Installation
Bolt lengths differ, and one bolt requires sealer because it enters the water jacket

32. Timing Belt Service
Many OHC engines use a synthetic rubber belt to operate the camshaft
Cogged belts are accurate, quiet, light, and dependable
Belt service is important
a broken or improperly timed belt could cause major engine damage

33. Timing Belt Assembly

34. Inspecting the Timing Belt
Inspect the belt for cracks, softening, and fraying
Most manufacturers recommend replacement at intervals of 50,000–100,000 miles (80,000–160,000 km)

35. Timing Belt Problems

36. Inspecting the Belt Tensioner
Always check the belt tensioner bearings

37. Removing a Timing Belt Sprocket
When reinstalling, align any key or dowel that positions the sprocket

38. Installing the Timing Belt
This camshaft sprocket mark is aligned with the belt marking and the timing mark on the engine

39. Installing the Timing Belt
Align the dowel with the timing pointer on the engine

40. Installing the Timing Belt
Slip the belt on and move the tensioner into the belt

41. Adjusting Belt Tension
Proper timing belt tension is very important to the belt’s service life
If it is too tight, it can wear out quickly or break
If it is too loose, the belt can flap, vibrate, or fly off

42. Adjusting Belt Tension
A pry bar may be used to adjust the tensioner

43. Adjusting Belt Tension
Moderate finger and thumb pressure should be needed to twist the belt

44. Installing the Timing Belt Cover
Tighten the fasteners to specs

45. Complete Engine Assembly
To complete the engine rebuild, install all remaining parts that do not prevent engine installation:
sensors and wiring
sending units
brackets
motor mounts
heat shrouds

46. Complete Engine
Spark plug wires and some hoses may be installed prior to engine installation

47. Installing the Engine Safety rules to remember:
keep your hands and feet out from under the engine
never work on an engine raised on a hoist
never move the hoist when the engine is raised high in the air—the hoist could flip over

48. Installation Steps On automatic transmission-equipped vehicles:
rotate the engine so the large hole in the flywheel faces down
rotate the torque converter so the drain plug is down for easy alignment
On manual transmission-equipped vehicles:
check the condition of the pilot bearing

49. Installation Steps
Position the lifting chain so the engine is raised in a level position
Slowly lower the engine into the vehicle while watching for clearance all around
Align the engine dowel pins with the holes in the transmission
Push the engine into the transmission so the dowel pins are fully seated

50. Installation Steps Start the bell housing bolts by hand
Check the torque converter or clutch alignment and install any bolts
Tighten the bell housing bolts
Finish installing the other components:
motor mounts
fuel lines, hoses, linkages, and wires

51. Installation Steps
Accessories and components for installation after the engine is in place

52. Starting the Engine After installation:
fill the engine with oil and the radiator with coolant
start the engine and run it at fast idle until warm, while watching the oil pressure
perform any final adjustments
check for any fluid leaks

53. Engine Break-In Done mainly to seat new piston rings
Typical procedures:
after warm-up, road test the vehicle, using moderate acceleration and deceleration
accelerate to about 40 mph (65 km/h)
coast down to about 20 mph (32 km/h), with a closed throttle
repeat several times while monitoring the oil pressure and coolant temperature

54. Brief the Owner Brief the owner about good break-in driving habits:
avoid prolonged highway driving for the first 100–200 miles (161–322 km)
don’t worry about oil consumption until after the first 2000 miles (3220 km)
check the oil and other fluids frequently
change the oil and filter after 2000 miles (3220 km)