Description and function of iB5

General form

Pos.	Spare Part No	Name
1		clutch slave cylinder
2		Gearbox breather
3		input shaft
4		output shaft
5		Differential

The iB5 manual transaxle used in the Focus is the so-called "twin shaft gearbox". Its design has been modified and now it uses a cable drive mechanism for the first time.

The aluminum gearbox housing consists of two sections. The rigidity of the crankcase is increased due to the inclusion of reinforcing ribs in its design. Crankcase sections are supplied in pairs and cannot be replaced individually. The clutch is hydraulically driven.

On a two-shaft gearbox, the gears of all gears are in constant mesh (except reverse gear). In each gear, the required gear ratio is provided by a pair of gears.

When reverse gear is selected, the direction of rotation of the output shaft is changed by using an intermediate gear.

All gears have a circular tooth, synchronized (except reverse gear) and mounted on plain bearings.

First and second gears have double synchronizers.

The iB5 manual transmission is filled with 2.5 liters of synthetic transmission fluid, specification WSD-M2C200-C. The filling level is 10-15 mm below the lower edge of the control hole. There is no need to change the transmission fluid.

Elements of a manual transmission in a block with a drive axle iB5

Pos.	Spare Part No	Name
1		Quick coupling
2		Oil seal (access outside)
3		Clutch slave cylinder with clutch release bearing (cannot be replaced separately)
4		Intermediate shaft front drive axle
5		Cylindrical spur gear
6		Tripod body ("tripod")
7		Synchronizer 1/2 gear
8		Synchronizer 3/4th gear
9		Synchronizer 5th gear
10		Gearbox breather

In the neutral position, none of the gears is connected to the output shaft through the corresponding synchronizers. Primary torque is not transmitted to the differential.

Internal shift mechanism

Pos.	Spare Part No	Name
1		5th/Reverse Select Rod Guide
2		Gear selector
3		Shift Stop Bushing
4		Mechanism of blocking of a shaft of a choice of transfers
5		Shaft of a choice of transfers
6		Return spring for reverse gear selector lever
7		Lever for selecting reverse gear
8		Retaining ring
9		5th/Reverse selector rod

Input shaft

Pos.	Spare Part No	Name
1		ball bearing
2		input shaft
3		Reverse intermediate gear
4		1st gear
5		Reverse gear
6		2nd Gear
7		3rd gear
8		4th gear
9		Retaining ring
10		5th gear
11		Retaining ring

Output shaft

Pos.	Spare Part No	Name
1		Roller bearing
2		output shaft
3		1st gear
4		Synchronizer inner ring
5		Tapered synchro ring
6		Synchronizer outer ring
7		Synchronizer 1/2 - th gear with reverse gear
8		Retaining ring
9		Synchronizer outer ring
10		Tapered synchro ring
11		Synchronizer inner ring
12		2nd Gear
13		Retaining rings
14		Retaining ring
15		3rd gear
16		Synchronizer ring 3rd gear
17		Synchronizer 3/4th gear
18		Synchronizer ring 4th gear
19		4th gear
20		ball bearing (closed on both sides)
21		Retaining ring
22		5th gear
23		Synchronizer ring 5th gear
24		Synchronizer 5th gear
25		lock bar

Double synchronizer

Pos.	Spare Part No	Name
1		Gear
2		Synchronizer inner ring
3		Tapered synchronizer ring
4		Synchronizer outer ring
5		Synchronizer hub

Double synchronizer

First and second gears have double synchronizers. By using a second synchronizer ring, the effective synchronizer surface is significantly increased compared to a single synchronizer. Double synchronization gives a significant improvement in the quality of gear shifting.

Dual synchronizers include an inner synchronizer ring, a tapered ring, an outer synchronizer ring, and a synchronizer hub.

The conical surface of the gear is no longer used. Synchronization occurs through the use of synchronizer rings and a conical ring that is attached to the gear.

Differential

The main elements of the differential include:

• Cylindrical spur gear
• Differential box with two tapered roller bearings
• Differential satellites
• Side gears

The gearbox and differential are enclosed in a two-section aluminum crankcase, which is flanged to the engine. The axle shafts of the drive axle are splined.

Primary torque is transmitted to the differential via a spur gear that is bolted to the differential case.


The differential box contains differential satellites mounted on one axle, as well as side gears having a splined connection with the axle shafts of the front drive axle.

If the front wheels have different speeds (e.g. when turning), the side gears can move the pinions of the differential.

Neutral gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear

First gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		1st gear
5		Synchronizer 1/2 - th gear
6		1st gear

Second gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		Synchronizer 1/2 - th gear
5		2nd Gear
6		2nd Gear

Third gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		3rd gear
5		Synchronizer 3/4th gear
6		3rd gear

Fourth gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		Synchronizer 3/4th gear
5		4th gear
6		4th gear

Fifth gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		5th gear
5		5th gear synchronizer
6		5th gear

Reverse gear

Pos.	Spare Part No	Name
1		input shaft
2		output shaft
3		output gear
4		Reverse gear
5		Reverse gear
6		Reverse intermediate gear

The reverse gear is driven by the input shaft. Its purpose is to change the direction of rotation of the secondary shaft when the reverse gear is engaged.

The intermediate reverse gear is supported by a needle bearing located on the intermediate axle and a bearing block.

The gear selection locking mechanism and the gear selection pin are fixed on the bushing in the gear selection housing. They use a spring-loaded ball to keep the selected gear engaged until another gear is selected.

The gear selector lock mechanism has three different positions.