Crankshaft Bearings and Related Component Service

Question 1

List 2 reasons for using proper lifting equipment when handling heavy engine components.

Answer 1

1. Prevent personal injuries.

2. Prevent component damage.

Question 2

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

a. hammer and soft metal drift.
b. puller assembly.
c. oxyacetylene torch.
d. pry bar.

Answer 2

B. Puller assembly.

Question 3

Explain why the main bearing caps must be reinstalled in their original position 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

a. counterweights and throws catching on the main bearing webs.
b. 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 possible damage from falling.

Question 6

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

Answer 6

to aide in diagnosis if required.

Question 7

The oil passages 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:
A. Journal Surfaces.
B. Bearing overlay.
C. Your body.
D. Crankshaft oil seals.

Answer 8

c. your body.

Question 9

The Machined surfaces of the crankshaft should be visually inspected for:
a.
b.
C.

Answer 9

a. scoring.
b. ridging.
c. discoloration (excess heat.)

Question 10

When using a chisel to remove the seal wear sleeve, care must be taken not to:
a.
b.

Answer 10

a. Do not cut through the wear sleeve and damage the crankshaft.
b. 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.
a.
b.
c.

Answer 11

a. fillets.
b. webs.
c. journal oil holes

Question 12

Crankshafts that have cracks in critically loaded areas are usually:

a. welded
b. reground
c. annealed
d. replaced

Answer 12

d. replaced.

Question 13

Crankshaft journals must be measured to determine:

Answer 13

a. minimum outside dimension
b. out of round.
c. taper

Question 14

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

Answer 14

a. fillet.

b. oil hole.

Question 15

The cranshaft in figure 67 has been setup to measure what?

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 the manufacturers specifications.

Question 17

A crankshaft with re-ground journals must be installed :
A. immediately after grinding.
B. with matching oversized bearings.
C. with matching undersized bearings.
D. heated to a specific temperature before installation.

Answer 17

c. with matching undersized bearings.

Question 18

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

Answer 18

a. check for direction of gear teeth.

b. check alignment of gear keyway and crankshaft key.

Question 19

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

a. heated with a torch before installation.
b. chilled in dry ice before installation.
c. installed with a hammer and soft metal drift.
d. heated to a specific temperature before installation.

Answer 19

D. heated to a specific temperature before installation.

Question 20

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

Answer 20

a. cracks in the hub.
b. deterioration of the rubber element.
c. 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 the three factors that could contribute to crankshaft replacement.
a.
b.
c.

Answer 22

a. incorrect or excessive loading.
b. incorrect service procedures.
c. a lubrication system problem.

Question 23

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

Answer 23

a. low oil level.
b. low oil pressure.
c. plugged oil passages.
d. improperly installed bearing inserts. (oil holes not aligned.

Question 24

Localized wearing on the face of the bearing could be caused by:

a. foreign material between the bearing shell and bore.
b. fuel dilation of the lubricating oil.
c. lubricating oil contaminated by coolant.
d. over-fueling the engine.

Answer 24

a. foreign material between the bearing shell and bore.

Question 25

Briefly explain how the upper bearing shell is removed during a 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 that so the pin pushes on the end of the bearing opposite the tang.

Question 26

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

Answer 26

b. bearing oil holes and tangs.

Question 27

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

Answer 27

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

Question 28

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

Answer 28

Rotation will destroy the plastigage and possibly cause bearing damage.

Question 29

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

Answer 29

no room for expansion and lubrication of the thrust surfaces.

Question 30

Flywheel housing alignment should be checked using:

a. plastigage.
b. feeler gauges.
c. a torque wrench
d. a dial indicator.

Answer 30

d. a dial indicator.

Question 31

Flywheel housing alignment should be checked using:

a. plastigage.
b. feeler gauges.
c. a torque wrench
d. a dial indicator.

Answer 31

d. a dial indicator.

Question 32

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

Answer 32

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

Question 33

Teflon lip crankshaft seal and wear sleeve assemblies should be:

a. lubricated with engine oil before installation.
b. installed as a unit with the proper tooling.
c. separated for inspection.
d. good for the lift of the engine.

Answer 33

b. installed as a unit with the proper tooling.

Question 34

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

Answer 34

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