Final Drive Part 2

Question 1

What happens to the torque during low friction conditions in an open differential vs a Limited slip differential?

Answer 1

Open -Torque of good traction wheel cannot exceed torque of low traction wheel

LSD - Clutch action connects the drive axels to reduce differential action

Question 2

What is the difference between a limited slip differential and a locking differential?

Answer 2

LSD - Uses clutch to connect the drive axel and reduce differential action
Locking- Uses a mechanism to prevent differential action

Question 3

LSDs are also called __________, ___________ or __________

Answer 3

Posi-Traction, Traction-lok or posi-units

Question 4

What is a clutch pack from an LSD comprised of?

Answer 4

• Stack of steel plated splined to the differential case
• Friction plates splined tot he side gears
• Preload spring fitted between side gears

Question 5

How does a clutch pack work?

Answer 5

• High traction wheel side will have a high thrust force developed from bevel gear separation (wedging) action.
• This results in the clutch pack being pressed firmly to become locked.
• Then power from the differential casing will flow directly to the high traction axel.

Question 6

Which type of differential has two cone shaped gears that slip while cornering and act as clutches to lock the side gears to the differential case?

Answer 6

Cone Type LSD

Question 7

When is a gerodisc LSD activated?

Answer 7

When the axle and differential case spin at different speeds

Question 8

What are the components of a gerodisc LSD?

Answer 8

Clutch pack and hydraulic pump

Question 9

How does a gerodisc work?

Answer 9

• Pump activated when axle and differential case spin at different speeds
• The pump’s output pressure applies the clutch pack which locks the side gear to the differential case.
• More wheel spin= more pump pressure

Question 10

How does a viscous LSD work?

Answer 10

Steel and friction plates connect axels. High-viscosity silicon fluid transfers torque through the friction plates.

Question 11

What is a torsen differential comprised of?

Answer 11

2 worm gears and 3 sets of helical gears

Question 12

What important principle about worm gears and wheels allow a torsen to function?

Answer 12

A spinning worm gear can rotate the wheel, but the rotating wheel cannot spin the worm gear.

Question 13

What happens in a torsen when making a right hand turn?

Answer 13

• The worm gear of the left axel will make the corresponding worm wheel spin on its own axis.
• The worm wheel on the right will spin in the opposite direction
• Spur gears ensure they are spinning at the same speed to give perfect differential action

Question 14

What allows a locking differential to function?

Answer 14

A centrifugally-operated latching mechanism