Contents Section: Automatic Trans All sections

Automatic Transmission/transaxle: Specifications Jaguar S-type I рестайлинг

Automatic Trans 1 illustration ~760 words

Specifications

CAUTIONUse only Shell M1375.4 Automatic transmission fluid. Use of any other fluids may result in a transmission malfunction or failure.
DescriptionIntervals
Normal MaintenanceNot necessary. Filled for life.
Severe Duty MaintenanceChange the fluid at 48,000 km (30,000 miles) intervals.

Fluid Maintenance

DescriptionSpecification
Transmission FluidShell M1375.4
SealantWSS-M4G323-A6
Metal Surface CleanerWSW-M5B392-A
High Temperature GreaseMolecote FB180

Lubricants, Fluids, Sealers and Adhesives

VehicleEngineApproximate LitersRefill Capacity Approximate dry capacity, includes cooler and tubes. Check the level at normal operating temperature. DO NOT OVERFILL. If it is necessary to add or change fluid, use only fluid which has been certified by the supplier as meeting the Jaguar Cars Ltd specification shown. U.S. Quarts
S-Type2.5L and 3.0L10.010.57
S-Type4.2L10.010.57
S-Type2.7L Diesel10.010.57

General Specifications

DescriptionNmLb-ftLb-in
Converter housing to engine retaining bolts4835
Transmission mount retaining bolts5037
Transmission fluid fill plugAAA
Transmission control module (TCM) and Main control valve body retaining screws853
Output shaft flange retaining nut6044
Torque converter retaining bolts5541
Transmission fluid cooler tube retaining bolt2317
Transmission fluid drain plug853
Transmission fluid pan, gasket and filter retaining screws853
A = refer to the procedure for correct torque sequence

Torque Specifications

Torque Demand

The torque demand downshift occurs (automatically) during part throttle acceleration when the demand for torque is greater than the engine can provide at that gear ratio. If applied, the transmission will disengage the TCC to provide added acceleration.

Torque converter

The torque converter is a three element unit containing a single plate lock up clutch. The lock up clutch can be controlled and engaged in any gear 1 to 6. The clutch is applied by removing transmission fluid pressure from one side of the plate. The torque converter transmits and multiplies torque. The torque converter is a three-element device

  1. Impeller assembly
  2. Turbine assembly
  3. Reactor assembly

The standard torque converter components operate as follows

  1. The impeller, which is driven by the engine, imparts a circular flow to the transmission fluid in the converter.
  2. This transmission fluid strikes the turbine wheel, which causes the flow to change its direction.
  3. The transmission fluid flows out of the turbine wheel close to the hub and strikes the stator, where its direction is changed again to a direction suitable for re-entering the impeller.
  4. The change in direction at the stator generates a torque reaction that increases the torque reaching the turbine.
  5. The ratio between turbine and impeller torque is referred to as torque multiplication or conversion.
  6. The greater the difference in speeds of rotation at the impeller and turbine, the greater the increase in torque; The maximum increase is obtained when the turbine wheel is stationary. As turbine wheel speed increases, the amount of torque multiplication gradually drops.
  7. When the turbine wheel is rotating at about 85 % of the impeller speed, torque conversion reverts to 1, that is to say torque at the turbine wheel is no higher than the torque at the impeller.
  8. The stator, which is prevented from rotating backwards by a freewheel and the shaft in the transmission housing, runs freely in the transmission fluid flow and overruns the freewheel. From this point on, the converter acts only as a fluid coupling. During the torque conversion process, the stator ceases to rotate and bears against the housing by the freewheel.

Scheme 20

Scheme 20
Item NumberDescription
1Torque converter retaining plate
2Lock-up clutch lined plate
3Torque converter cover
4Turbine
5Impeller
6Stator
7Stator freewheel
8Space behind lock-up clutch
9Lock-up clutch piston

Torque Converter Lock-up Clutch

The torque converter lock-up clutch is a device that eliminates slip in the torque converter and therefore helps to keep fuel consumption to a minimum.

The torque converter lock-up clutch is engaged and released by the control system. During the actuating phase, a slight difference is selected between the impeller and turbine wheels.

Pressure at the torque converter lock-up clutch piston is determined by an electronic pressure control valve.

The torque converter lock-up clutch can be controlled and engaged in any gear from 1 to 6. When decoupling takes place the actuating clutch A in the transmission is dependent on load and output speed.

When the torque converter lock-up clutch is released, transmission fluid pressures behind the lock-up clutch piston turbine area are equalized. The direction of flow is through the turbine shaft and the area behind the piston into the turbine area.

To engage the torque converter lock-up clutch the direction of transmission fluid flow is changed and reversed by a valve in the hydraulic control unit. At the same time the space behind the torque converter lock-up clutch piston is vented.

Oil pressure extends from the turbine area to the torque converter lock-up clutch piston and presses it against the cover outer shell of the torque converter. This locks the turbine wheel by way of the lined disc between the piston and the cover and enables the drive to pass with limited slip to the planetary gear train in normal operating conditions.

Torque Converter Monitoring

The TCM checks that the torque converter can be locked correctly. If torque converter lock-up does not occur correctly the TCM performs the appropriate fail-safe action of opening the Torque converter clutch.

Torque Converter Lock-up Control

The TCM controls how the torque converter clutch is engaged as a function of the accelerator pedal position , output speed, transmission fluid temperature, gear selected and shift program. Lock-up is possible in all forward gears, but usually it is restricted to fourth, fifth and sixth gears. To make use of the comfort enhancing effect of the torque converter, the converter clutch can be disengaged prior to a downshift or up-shift. The torque converter lock up clutch is always modulated to allow for controlled slip, to further improve the shift quality.