Workshop Manuals Factory service & repair Alfa Romeo
01 General information02 Specifications03 Manufacturing data and tolerances04 Tightening torques05 Fluids and lubricants06 Maintenance07 Diagnostic checks08 Engine09 Clutch10 Gearbox and differential11 Transmission (4x4)12 Axles and driveshafts13 Brakes14 Steering15 Suspension and wheels16 Heating, air conditioning and auxiliary units17 Electrical equipment18 Body fittings19 Body panels and frame20 Wiring diagrams and electrical functions21 Wiring harnesses22 Connectors and pin-outs23 Fault diagnosis24 Special tools
Alfa Romeo 159 Factory Service Manual (2005-2011)10 · Gearbox and differential
10 · Transmission

Clutch control

Make
Alfa Romeo
Model
159 Factory Service Manual
Year
2005–2011
Section
General › Clutch control
Gearbox and differentialClutch control

CLUTCH CONTROL

2.4 JTD 20V

CO-AXIAL HYDRAULIC OPERATION (CSC)

The (CSC) operating system comprises an actuating cylinder located on the bellhousing which controls the clutch, working co-axially in relation to the main shaft.

CLUTCH CONTROL
  • 1 Air bleed plug
  • 2 Oil pressure inlet
  • 3 Co-axial hydraulic operation assembly

F40 GEARBOX

The diagrams show the F40 gearbox assembly with three propeller shafts.

CLUTCH CONTROL
  • 1 Gear engagement assembly
  • 2 Layshaft C
  • 3 Main shaft A
  • 4 Main shaft B

The configuration of the gearbox is transverse with three shafts: one main shaft (A) and two layshafts (B and C).

The main shaft A contains five fixed gears designed to transmit power to the gears for 1st, 2nd, 3rd, 4th, 5th 6th and Reverse speeds on the two layshafts B and C which they mesh with constantly.

The two layshafts B and C both have a pinion which meshes constantly with the differential ring gear.

The layshaft B contains the 1st and 2nd speed and the 5th and 6th speed gear trains, whilst the layshaft C contains the 3rd and 4th speed and the reverse gear trains.

The components inside the gearbox are lubricated dynamically, by means of the oil flowing through the ducts in the casings and the ports in the shafts as well as additional plastic ducts; all of this allows improved torque transmission and better protection against wear.

The clutch is hydraulically operated with the C.S.C. system co-axial on the main shaft inside the gearbox.

This system produces the following advantages:

  • recovery of the clutch plate wear which allows the load on the clutch pedal to remain constant throughout the life of the vehicle
  • improved acoustic comfort
  • reduction of the engagement force
  • no vibrations / shuddering of the lever

Gearbox in neutral position

The diagram below shows the position of the gearbox when no gear is engaged.

CLUTCH CONTROL
  • 1 1st speed gear
  • 2 1st and 2nd speed synchronizer
  • 3 2nd speed gear
  • 4 3rd speed gear
  • 5 3rd and 4th speed synchronizer
  • 6 4th speed gear
  • 7 5th speed gear
  • 8 5th and 6th speed synchronizer
  • 9 6th speed gear
  • 10 reverse gear
  • 11 Reverse synchronizer
  • 12 Differential
  • A. Main shaft
  • B. Layshaft
  • C. Layshaft

TRANSMISSION OF POWER IN THE VARIOUS GEARS

First speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear for 1st speed on the layshaft B.

When 1st speed is engaged, the synchronizer 2 joins the driven gear 1 with the layshaft B and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • B. Layshaft
  • 1 1st speed gear
  • 2 Synchronizer
  • 12 Differential

Second speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear 3 for the 2nd speed on the layshaft B.

When 2nd speed is engaged, the synchronizer 2 joins the driven gear 3 with the layshaft B and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • B. Layshaft
  • 2 Synchronizer
  • 3 2nd speed gear
  • 12 Differential

Third speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear 4 for 3rd speed on the layshaft C.

When 3rd speed is engaged, the synchronizer 5 joins the driven gear 4 with the layshaft C and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • C. Layshaft
  • 4 3rd speed gear
  • 5 Synchronizer
  • 12 Differential

Fourth speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear 6 for 4th speed on the layshaft C.

When 4th speed is engaged, the synchronizer 5 joins the driven gear 6 with the layshaft C and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • C. Layshaft
  • 5 Synchronizer
  • 6 4th speed gear
  • 12 Differential

Fifth speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear 7 for 5th speed on the layshaft B.

When 5th speed is engaged, the synchronizer 8 joins the driven gear 7 with the layshaft B and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • B. Layshaft
  • 7 5th speed gear
  • 8 Synchronizer
  • 12 Differential

Sixth speed

The power enters the gearbox via the mainshaft A and is transmitted, through the fixed drive gear, to the driven gear 9 for 6th speed on the layshaft B.

When 6th speed is engaged, the synchronizer 8 joins the driven gear 9 with the layshaft B and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • B. Layshaft
  • 8 Synchronizer
  • 9 6th speed gear
  • 12 Differential

Reverse gear

The power enters the gearbox via the main shaft A through the drive gear 1 for the 1st speed on the layshaft B.

This gear remains free on its shaft and only works as an idler for the power between the main shaft A and the driven gear 10 for reverse on the layshaft C.

When reverse is engaged, the synchronizer 11 joins the reverse gear 10 with the layshaft C and the power is transmitted to the differential 12 thereby completing the kinematic chain.

CLUTCH CONTROL
  • A. Main shaft
  • C. Layshaft
  • 1 1st speed gear (neutral on the shaft)
  • 10 Reverse gear
  • 11 Reverse synchronizer
  • 12 Differential

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