Ford Workshop Service and Repair Manuals

The iB5 manual transmission is a two shaft transmission.

All gear wheels are helical toothed, synchronised (except reverse gear) and run in plain bearings.

1st and 2nd gears are double synchronised.

There is no need to change the oil.

Transmission construction

Input shaft

Output shaft

Double synchronisation

1st and 2nd gears are double synchronised.

The effective synchronisation surface for double synchronisation is almost twice that of simple synchronisation. Because of this, the speeds of the gearwheels are equalised much faster, which considerably improves gearshifting comfort.

Differential assembly

The differential assembly is built into the transmission housing.

The drive torque is transmitted to the differential by the crown wheel which is bolted to it.

The differential assembly contains differential pinion gears mounted on a spindle and the axle halfshaft pinion gears which connect to the front wheel axle halfshafts through helical gearing.

The axle halfshaft pinion gears can revolve around the differential pinion gears when the road wheel speeds are different (e.g when cornering).

On vehicles without Anti-lock Brake System (ABS) a VSS detects the speed of the differential assembly at the VSS sender wheel.

On vehicles with ABS the VSS sender wheel is also installed. The VSS is however not installed in this case. A plug with an O-ring closes the corresponding bore instead.

Internal shift mechanism

Layout

The shift locking bush prevents two gears from being engaged at the same time.

The selector interlock maintains engagement of the selected gear.

Both the shift and the select process is performed through the selector shaft.

Select movement

The axial movement of the selector cable is transferred at the transmission to the selector shaft which can turn in its bearing.

If the gearshift lever is moved to the left or right, the selector shaft and the selector boss both turn together in the corresponding direction.

As this happens, the selector shaft is guided by a pin in the selector gate.

The selector boss selects the required selector fork.

At the same time the shift locking bush prevents access to other gear combinations.

Shift movement

After the gear pair to be shifted has been selected, the shift movement takes place.

Here the axial movement of the shift cable at the transmission produces an axial movement of the selector shaft.

If the gearshift lever is moved forwards or backwards, the selector shaft and the selector boss both move vertically together.

As this happens, the selector shaft is guided by a pin in the selector gate.

The selector boss shifts the required selector fork.

At the same time the shift locking bush prevents access to other gear combinations.

Engage reverse gear

In order to select reverse gear, the gearshift lever must be moved to the right over and past the reverse gear inhibit device. As this occurs the axial movement of the selector cable is transferred to the selector shaft which can turn in its bearing.

When shifting into reverse gear, the gearshift lever is moved backwards. The selector boss engages in the 5th gear/reverse gear shift rod, which in turn engages through a pin in the reverse gear selector shaft.

During the select and shift process the selector shaft is guided through the selector gate by a pin.

The reverse gear idler is slid by the reverse gear selector shaft and reverse gear is engaged.

At the same time the shift locking bush prevents access to other gear combinations.

Power transmission in the individual gears