Wheel-End/Drivelines/Rear Axles Flashcards
What wheel mounting system is standard on PB trucks?
Hub-piloted (PHP-10) - close tolerances between wheel center and machined surface on hub.
Which axles have an oil seal sight glass?
All non-driving axles on PB trucks
Key features of driveline
- strong enough for low-gear torque
- light and dynamically balanced to prevent noise/vibration
Type of joint used on driveline connections
Slip joint to allow movement with up/down motion of suspension
Where is the 1st slip joint
Output joint where shaft attaches to transmission
What do u-joints do
Allow for driveshaft to operate at different angles (e.g. sloped roads)
When is a midship bearing used?
What does it do?
- used on long wheelbase vehicles
- Intermediate bearing in case 2 or more driveshafts are required
What material does PB use for driveshafts?
Steel tubing
What is purpose of rear axle?
- Support the load
- Retain and position the wheels
- Act as a mounting surface for the suspension
- Provide support for the braking system
- Encase the differential gearing and axle shafts
- Provide power transfer to the ground
- Allow a differential action to each side during a turn
What is used to allow wheels to go different speeds in turns?
A differential is used
In standard rear axles - what are the 2 gears called?
- Pinion (input or driving gear)
- Ring gear (driven gear)
How is rear axle ratio calculated?
teeth on ring gear divided by # teeth on pinion gear
Which applications typically use a double reduction axle?
heavier duty w/ addt’l strength and torque
- dump
- mixer
- off-highway
What are 2 methods for double reduction?
- planetary gear (addt’l planetary set inside ring gear)
- hypoid-helical (ring gear on shaft that has helical drive gear)
How does 2-speed rear axle work?
low range - planetary gears act normal
high range - planetary locked
What is a tandem axle?
combine two single axle units with a power divider; they are connected by an interaxle driveline.
What is interaxle differential?
-Allows rear tandem axles to operate at diff speeds during turning or uneven reads
Why do you lock differentials?
Avoid slip to allow for extra traction required
How is differential locked?
dash mounted control switch that operators air or electric over air
What are typical rear axle ratios?
between 2.64 to 7.17
What are the 2 auxiliary axles?
Push and tag (neither are driven)
