Differencial Drive

A typical part time 4WDS found in pichups and old SUVs is a rear wheel drive. The transmission is directly connected to the transfer case , form there one shaft turns the rear and another front axle.

When 4WDS is switched ON the transfer case lock both the drive shafts, which results in each axle receiving half of the torque which is produced in engine.

This system has two drawbacks

1. It cannot be used on-road because of the locked transfer case.

2. The system get stuck when both the side wheels are on a slippery surface like loose gravel. Both the axel looses traction in this case.

This can be avoided by the hummer Differencial drive.