Transmission and Drivetrain: Description and Operation

Driveline System
The driveline transfers engine torque to the drive wheels. On 2.0L vehicles the power is transmitted through the transaxle to the front drive halfshafts. On 2.5L and 3.0L vehicles the power is transmitted through the transaxle to the transfer case. The transfer case then splits the torque 40% to the front drive halfshafts and 60% to the driveshaft which is connected to the rear drive differential and the rear drive halfshafts.

The engine is installed at a specific angle. This is determined by the engine mounts. If the engine angle is out of specification, the engine mounts must be inspected for damage and new ones installed if necessary.

Driveline Vibration
Driveline vibration exhibits a higher frequency and lower amplitude than high-speed shake. Driveline vibration is directly related to the speed of the vehicle and is usually noticed at various speed ranges. Driveline vibration can be felt as a tremor in the floorpan or is heard as a rumble, hum or boom. Driveline vibration can exist in all drive modes, but may exhibit different symptoms depending upon whether the vehicle is accelerating, decelerating, cruising or coasting. Check the driveline angles if the vibration is particularly noticeable during acceleration or deceleration, especially at lower speeds.

In order to diagnose vibrations in the driveshaft, refer to the Jaguar Approved Diagnostic System.

Driveline Angle
On 2.0L vehicles the driveline angularity is the angular relationship between the transaxle and the halfshafts. On 2.5L and 3.0-L vehicles the driveline angularity is the angular relationship between the transfer case drive pinion, the driveshaft and the rear differential drive pinion. On 2.OL, 2.5L and 3.OL vehicles the factors determining driveline angularity include ride height and engine mounts.

If the wheels and tires and driveline angle are not the cause, carry out the NVH tests to determine whether the concern is caused by a condition in the driveline.