Bearings, Seals Bearings, Seals and Greasesand Greases

Chapter 53Chapter 53

Page 762Page 762

BearingsBearings

Wheel bearings are lubricated with Wheel bearings are lubricated with grease, which also protects the metal grease, which also protects the metal from corrosion and helps conduct from corrosion and helps conduct heat. Wheel bearings need to be heat. Wheel bearings need to be cleaned and re-greased every 50-cleaned and re-greased every 50-thousand miles. It is good practice to thousand miles. It is good practice to do one side at a time to prevent do one side at a time to prevent mixing up any components. mixing up any components.

Pieces of the bearing may have broken Pieces of the bearing may have broken off, resulting in a high-pitched sound off, resulting in a high-pitched sound while driving. This is called "spalling". while driving. This is called "spalling".

SpallingSpalling

A low-pitched sound while driving is A low-pitched sound while driving is caused when the bearing race has caused when the bearing race has indentations from shock loads. This is indentations from shock loads. This is called "brinelling". called "brinelling".

Wheel bearings require a lubricant that Wheel bearings require a lubricant that is capable of withstanding high is capable of withstanding high temperatures and pressures. Normal temperatures and pressures. Normal chassis grease does not possess these chassis grease does not possess these properties, so you must use the properties, so you must use the manufacturer's recommended wheel manufacturer's recommended wheel bearing grease or you risk premature bearing grease or you risk premature bearing failure. bearing failure.

Wheel Bearing ServiceWheel Bearing Service

Sealed BearingDoesn't require grease

Bearing Cross SectionBearing Cross Section

Sealed TypeSealed Type

Gaskets and SealsGaskets and Seals

Gaskets and SealsGaskets and Seals

GreaseGrease

Our biggest concern is to make Our biggest concern is to make sure we are using wheel bearing sure we are using wheel bearing “rated” grease when servicing “rated” grease when servicing bearings.bearings.

Chassis grease will not protect Chassis grease will not protect from the heat and loads a wheel from the heat and loads a wheel bearing experiences.bearing experiences.

Your Job.Your Job.

Complete chapter Questions 1-15 Complete chapter Questions 1-15 (review) and 1-10 (ASE-style). Page 781(review) and 1-10 (ASE-style). Page 781

Write on a separate paper and write Write on a separate paper and write out the complete question and your out the complete question and your answer. ( do not write the other answer answer. ( do not write the other answer options). options).

Complete the chapter worksheet (I will Complete the chapter worksheet (I will give it out). You may write on it. give it out). You may write on it.

File all items in your note book.File all items in your note book. Notebooks will be graded in the future.Notebooks will be graded in the future.