Transcript DIFFERENTIALS and DRIVE AXLES

DIFFERENTIALS
and
DRIVE AXLES
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Chapter 7
Page 137
• Classroom Manual
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Page 247
• Lab Manual
OBJECTIVES
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Describe the purpose of a differential.
Identify the major components of a
differential and explain their purpose.
Explain the need for drive pinion bearing
preload.
Describe the difference between hunting,
CBC
and nonhunting gear sets.
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OBJECTIVES
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Explain the purpose of the major bearings
within a differential assembly.
Describe the operation of a limited-slip
differential.
Describe the construction and operation of a
rear axle assembly.
Identify the two major designs of rear axle
housings.
INTRODUCTION
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Solid rear axle (with leaf or coil springs.)
IRS (Independent Rear Suspension)
Hypoid gear set (pinion below centerline)
FWD (helical cut ring and pinion)
Differential (allows different wheel speeds)
CBC
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Leaf Spring
Suspension
SOLID
REAR
AXLE
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Coil Spring
Suspension
HYPOID GEAR SET
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Pinion centerline is
below Ring Gear
centerline.
CBC
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FWD HELICAL CUT
RING & PINION
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Pinion can be
called the
Main shaft,
Intermediate
shaft, or
Transfer shaft.
DIFFERENTIAL
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Allows each drive
wheel to travel at
different speeds,
and different
distances.
FUNCTION and
COMPONENTS
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Pinion mounted on two tapered bearings.
Differential case mounted on two tapered
bearings 90 degrees to the pinion.
Pinion and differential bearings are
PRELOADED no play.
Differential assembly is case, side gears,
CBC
spider gears, and pin.
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DIFFERENTIAL
OPERATION
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Allows drive wheels to operate at different
speeds, and travel different distances.
When traveling straight ahead both wheels
rotate at the same speed and same distance.
Page 140 C
CBC
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AXLE HOUSINGS
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Two types of differential carriers:
• Integral carrier
– Salisbury or Hotchis
• Removable carrier
– Third member
Page 145 C
CBC
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DIFFERENTIAL GEARS
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Two types of RWD differential gears:
• Spiral Bevel
– Ring & Pinion centerlines intersect
• Hypoid
– Pinion centerline is below Ring gear centerline
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Hypoid lube required!
Drive - Coast
Page 146 C
CBC
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GEAR RATIO
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Number of INPUT gear revolutions to equal
One OUTPUT revolution.
Any # >1:1 = Underdrive
1:1 = Direct drive
Any # <1:1 = Overdrive
Driven
Drive
Page 148 C
CBC
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DETERMINING FINAL
DRIVE
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Decipher the “code”
• On the tag under a cover bolt.
• Differential housing tube.
• Door post.
Page 149 C
CBC
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