Chapter 6

Question 1

List two reasons for using proper lifting equipment when handling heavy engine components:

Answer 1

Prevent personal injuries.

Prevent component damage.

Question 2

Vibration dampeners that are press fit on the crankshaft should be removed using a

Answer 2

Puller assembly.

Question 3

Explain why the main bearing caps must be installed in their original positon on the cylinder block.

Answer 3

To maintain main bearing bore geometry.

Question 4

List two problems to look for when lifting the crankshaft from the cylinder block:

Answer 4

Counterweights and throws catching on the main bearing webs.
Binding between the thrust bearings and the crankshaft.

Question 5

Explain why proper storage of the crankshaft is so important:

Answer 5

The crankshaft must be stored and secured properly to prevent warpage and possibly damage from falling/

Question 6

Why should bearing shells be marked and kept together after removal from cylinder block?

Answer 6

To aid in diagnosis if required.

Question 7

The oil passageways in the crankshaft should be thoroughly cleaned to prevent:

Answer 7

Prevent foreign material from being flushed into the bearings when the engine is started.

Question 8

During cleaning operations, compressed air should never be directed at

Answer 8

Your Body

Question 9

The machined surfaces of the crankshaft should be visually inspected for.

Answer 9

Scoring
Ridging
Discoloration

Question 10

When using a chisel to remove the seal wear sleeve from the crankshaft flange, care must be taken not to:

Answer 10

Do not cut through the wear sleeve and damage the crankshaft.
Do not hit the sleeve directly over a bolt hole - this can dent the crankshaft.

Question 11

List the three loaded areas of the crankshaft that require inspection for cracks:

Answer 11

Fillets
Webs.
Journal oil holes.

Question 12

Crankshafts that have cracks in critically loaded areas are usually:

Answer 12

Replaced

Question 13

Crankshaft journals must be measured to determine:

Answer 13

Minimum ouside diameter (wear)
Out of round
Taper

Question 14

Which two areas of the journal should be avoided when measuring the journal surface?

Answer 14

Fillet

Question 15

The crankshaft in figure 67 has been set up to measure:

Answer 15

Straightness or runout

Question 16

Explain how to verify the size of the journals on a re-ground crankshaft.

Answer 16

Measure the journals and compare with manufacturer’s specifications.

Question 17

A crankshaft with re-ground journals must be installed:

Answer 17

With matching undersized bearings.

Question 18

List two checks that should be performed when installing the crankshaft gear.

Answer 18

Check for direction of gear teeth. (chamfer and timing marks.)
Check for alignment of gear keyway and crankshaft key.

Question 19

When replacing the ring gear on a flywheel, the ring gear should be:

Answer 19

Heated to a specific temperature before installation.

Question 20

List three conditions that would indicate that a rubber element vibration dampener needs replacement:

Answer 20

Cracks in the hub.
Deterioration of the rubber element.
Misalignment or movement between the hub and the inertia mass.

Question 21

Briefly explain why a dent in the housing of a viscous dampener could be cause for replacement.

Answer 21

A dent in the housing will cause binding of the inertia mass due to close internal tolerances.

Question 22

List three factors that could contribute to crankshaft failure:

Answer 22

Incorrect or excessive loading.
Incorrect service procedures.
A lubrication system problem.

Question 23

List four factors that could cause a bearing failure due to lack of lubrication.

Answer 23

A low oil level.
Low oil pressure.
Plugged oil passages.
Improperly installed bearing inserts. (oil supply holes misaligned.)

Question 24

Localized (spot) wear on the face of a bearing could be caused by:

Answer 24

A foreign material between the bearing shell and the bore.

Question 25

Briefly explain how the upper bearing shell is removed during an in frame bearing replacement.

Answer 25

Install a bearing removal pin in the oil hole of the journal and rotate the crankshaft by hand so the pin pushes on the end of the bearing opposite of the tang.

Question 26

After installing the upper bearing shells during a major overhaul, check alignment of the _________ before the crankshaft is installed.

Answer 26

bearing oil holes and tangs.

Question 27

Briefly explain why tightening main cap bolts with a torque wrench is usually done in steps.

Answer 27

Stretches all the bolts evenly and reduces the chance of cylinder block distortion.

Question 28

When tightening fasteners using the torque and turn method, turning the fastener is turned a specific number of degrees to:

Answer 28

achieve a specific amount of bolt stretch

Question 29

Briefly explain why the crankshaft should not be rotated when using Plastigage to check bearing clearance.

Answer 29

Rotating will destroy the plastigage and possibly cause bearing damage.

Question 30

Why would the thrust bearings be damaged if an engine had insufficient crankshaft end play?

Answer 30

No room for expansion and lubrication of the thrust surfaces.

Question 31

Flywheel housing alignment should be checked using:

Answer 31

a dial indicator

Question 32

List three precautions that should be observed when installing crankshaft oil seals.

Answer 32

Use proper seal installation tools. Make sure lip is not rolled or damaged when being pushed onto the crankshaft. Ensure that seals are installed square and to the right depth.

Question 33

Teflon lip crankshaft seal and wear sleeve assemblies should be:

Answer 33

Installed as a unit with the proper tooling.

Question 34

What checks should be preformed before installing the vibration dampener and flywheel?

Answer 34

Check the mounting surfaces of the vibration dampener, flywheel and crankshaft for burrs and foreign material that could cause runout.