Workshop Manuals Factory service & repair Fiat
01 General information02 Specifications03 Manufacturing data and tolerances04 Tightening torques05 Fluids and lubricants06 Maintenance07 Diagnostic checks08 Engine09 Clutch10 Gearbox and differential11 Axles and driveshafts12 Brakes13 Steering14 Suspension and wheels15 Heating, air conditioning and auxiliary units16 Electrical equipment17 Body fittings18 Body panels and frame19 Wiring diagrams and electrical functions20 Wiring harnesses21 Connectors and pin-outs22 Fault diagnosis23 Special tools
Fiat Idea Factory Service Manual (2003-2012)10 · Gearbox and differential
10 · Transmission

Introduction - MANUAL GEARBOX AND DIFFERENTIAL

Make
Fiat
Model
Idea Factory Service Manual
Year
2003–2012
Section
Manual gearbox and differential › Introduction - MANUAL GEARBOX AND DIFFERENTIAL
Gearbox and differentialIntroduction - MANUAL GEARBOX AND DIFFERENTIAL

Introduction - MANUAL GEARBOX AND DIFFERENTIAL

The structure of the gearbox consists of:

  • a gearbox casing which contains and supports the main and layshafts, gear selector forks and shafts and the gear selector and engagement device;
  • a rear cover which contains the 5th speed gears and the rear bearing retaining plate for the main and layshafts
  • a bell housing which contains the clutch, the thrust bearing and the control linkage.

Main shaft

The main shaft consists of:

  • 1st, 2nd and reverse gears fitted directly on the shaft;
  • 3rd, 4th and 5th speed gears fitted on the shaft.

The main shaft is supported by means of two ball bearings for the C.510 gearbox, whilst the C.514 version has a front roller bearing and a rear ball bearing.

Layshaft

The layshaft consists of:

  • 1st, 2nd, 3rd, 4th and 5th gears fitted on the shaft

The layshaft is supported on:

  • a front roller bearing
  • a rear ball bearing

Gears

The gears are the following type:

  • helical toothed for the forward speeds
  • straight toothed for reverse.

Synchronizers

The synchronizers for the forward speeds are the Borg-Warner type.

The arrangement for the synchronizers is the split type because the synchronizers for the 1st and 2nd speeds are fitted on the layshaft, whilst those for the 3rd, 4th and 5th speeds are on the main shaft.

This solution reduces gearbox noise in neutral from the moment 3 of the 5 (or 6) pairs of gears are not driven.

In addition, the engagement and synchronization loads are reduced as a result of the corresponding reduction in the inert masses rotating downstream of the crankshaft.

Differential

On the C.510 and C.514 gearboxes, the differential unt is located at the rear of the gearbox casing.

It consists of:

  • a crown wheel and pinion reduction
  • a differential housing constructed in a single piece which includes the planet and satellite gears.

The differential is supported by two conical roller bearings.

- The planet gears have a splined profile with which the two flanged couplings connected to the two driveshafts which transmit the power to the wheels mesh.

The drive gear for the speedometer is fitted on the outside of the differential housing.

Introduction - MANUAL GEARBOX AND DIFFERENTIAL

1, Thrust bearing

2, Speedometer gear

3, Planet gears

4, Conical roller bearing

5, Satellite gears

6, Ring gear

7, Conical roller bearing

8, Differential housing bearing adjustment shim

9, Layshaft

10, Main shaft

Differential

Introduction - MANUAL GEARBOX AND DIFFERENTIAL

1, Thrust bearing

2, Main shaft

3, Satellite gears

4, Planet gears

5, Ring gear

6, 1st speed driven gear.

7, 2nd speed driven gear.

8, Gearbox casing

9, 3rd speed driven gear

10, 4th speed driven gear

11, Rear bearing retaining plate

12, 5th speed driven gear.

13, Layshaft

14, Rear cover

5th speed drive gear

16, Bell housing

Parts & tools for this job For 2003 Fiat Idea

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