Subaru Forester

1997-2005 of release

Repair and operation of the car

Subaru Forester
+ Subaru Forester cars
+ Maintenance instruction
+ Routine maintenance
+ Engine
+ Cooling systems, heating
+ Power supply system and release
+ Engine electric equipment
+ Control systems of the engine
- Gear shifting box
   - 5-staged manual box of gear shifting (MBGS)
      General information
      Removal and installation of a box of gear shifting
      Preparation for performance of repair work on restoration of RKPP
      Dismantling and assembly of the transfer case, service of components
      Capital repairs of RKPP of all-wheel drive models
      Service of the drive of gear shifting
      Service of the lever of switching of the transfer case
   + 4-staged automatic transmission (AT)
+ Coupling, transmission line
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment

5-staged manual box of gear shifting (MBGS)

General information

For a complete set of the models of cars considered in the present manual the 5-staged manual box of gear shifting (MBGS), or the 4-staged automatic transmission (AT) are used.

In this part of the present Chapter manual boxes of gear shifting are considered, and also assembly of the transfer case, is devoted to automatic transmission the Part the 4-staged automatic transmission (AT).

In view of complexity of a design of RKPP, absence on free sale of necessary replaceable internal components and need of use of the special equipment, authors of the present manual do not recommend to owners of cars to carry out capital repairs of the transmission independently. Repair of a box in the conditions of a workshop of car service is rather expensive operation, in a type of what, it is necessary to consider alternative options of replacement of the failed block new or restored. Any useful information on repair and replacement of transmission can be received at car repair shops of the Subaru company. Regardless of the chosen way of elimination of problems (repair or replacement), independent dismantle of a box from the car will allow to reduce material inputs significantly.

Models with the constant all-wheel drive (Full Time)

Design of RKPP used for a complete set of models with the constant four-wheel drive


1 — the Case RKPP 2 — the Conducted gear wheel of intermediate transfer of the drive of back wheels 3 — the Shaft of the leading gear wheel of the main transfer 4 — the Secondary shaft 5 — the Viscous coupling 6 — Interaxal differential 7 — the Leading gear wheel of intermediate transfer of the drive of back wheels 8 — Lengthening

RKPP of the front-wheel Subaru cars (Legacy, Impreza, Outback) which unite previously in the uniform block with the transfer case are taken as a basis of a design of transmissions of all-wheel drive models. The interaxal differential and intermediate transfer of the drive of back wheels is installed in the transfer case.

The interaxal differential is supplied with the viscous coupling installed between its output shaft.

Many details of transmissions of all-wheel drive models, such, as: the main case, a main shaft, forward differential, etc., are unified with details of the boxes used on front-wheel models of the class Legacy/Impreza/Outback.

Besides five-step also ten-step RKPP which besides the main 5-staged mechanism are supplied with also 2-staged reducer established ahead of a main shaft and allowing to change the general transfer relation of a box by the choice of the raising or lowering mode of the functioning are issued.

Models with the switched-off drive of back wheels

Design of RKPP used for a complete set of models with the switched-off drive of back wheels


1 — the Conducted gear wheel of intermediate transfer of the drive of back wheels 2 — the Rod of turning on of the coupling 3 — the Conducted gear wheel of intermediate transfer of the drive of back wheels

In assembly of the RKPP transfer case of this type intermediate transfer of the drive of back wheels with a possibility of shutdown by means of the gear coupling is established. The interaxal differential in such boxes is not used.

Design and principle of functioning of interaxal differential

Design of interaxal differential with the viscous coupling


1 — From a secondary shaft of RKPP 2 — To a shaft of the leading gear wheel of the main transfer of the drive of forward wheels 3 — To a shaft of the leading gear wheel of intermediate transfer of the drive of back wheels

The interaxal differential is executed according to the planetary symmetric scheme on conic gear wheels. Feature used on the models of interaxal differentials considered in the present manual is use of the viscous coupling which is switched on between output in bulk.

Thanks to such design of interaxal differential the best redistribution of traction effort on driving wheels of the car is reached, stability of the vehicle increases, its controllability improves, in particular at the movement on a slippery paving.

Several disks (plates) with external and internal gearing located serially are installed in the case of the viscous coupling.

Design of the viscous coupling of interaxal differential


1 — the Cover 2 — the Case 3 — the Nave 4 — the Disk with internal gearing 5 — the Prostavochny ring 6 — the Disk with external gearing 7 — the Epiploon

Disks with external gearing are equipped with the teeths located from their outer edge and entering gearing with internal vents of the case of the coupling. Teeths of disks of internal gearing, in turn, enter gearing with external vents on a nave surface.

For distributing of disks with external gearing between them special prostavochny rings are established. Between disks with internal gearing there are no such rings and they can freely move on nave vents in the axial direction, everyone - between two adjacent disks of external gearing.

The internal cavity of the coupling is filled with special silicone liquid. Two epiploons executed in the form of rings of H-shaped section prevent a liquid effluence from the coupling.

Liquid nevertheless can filter from the coupling under the influence of internal pressure that lead to an assembly exit out of operation. Pressure in the coupling increases when angular speeds of rotation of forward and back wheels considerably differ from each other for a long time that can happen during towage of the vehicle to a separation of one of axes from the earth.

Use of the viscous coupling allows to redistribute torque between lobbies and back driving wheels, for example, at movement of the car on the slippery road when the coefficient of coupling of wheels with a covering can vary considerably. As a result of functioning of the coupling the bigger torque is the share of the wheels rotating with a smaller angular speed. During the movement on the direct road with a good covering, the torque is distributed between forward and back wheels evenly.

Safety mechanism of inclusion of transfer of a backing

Design of the safety mechanism of inclusion of transfer of a backing


1 — the Sleeve 2 — the cam Roller 3 — the Cam 4 — the Returnable spring of the roller 5 — Pruzhina of a cam 6 — the Persistent plate	7 — the Lock ring 8 — Pruzhina 9 — the Ball 10 — the Sealing ring 11 — the switching Lever 12 — Adjusting laying

Sleeve (1) of the safety mechanism bolts of a privernut to a transmission case. The roller (2) is placed in a sleeve. Freely turned cam (3) withheld in a sleeve by a special ledge is put on narrower end of the roller.

The returnable spring (4) established inside wrings out the roller to the left, besides, the spring (5) established between a cam and a sleeve wrings out a cam also to the left and in the direction of rotation. Both springs rest against a plate (6) which is established in a sleeve and is recorded by a lock ring (7). The roller is equipped lysky, providing by means of the ball (9) which is drawn in by a spring (8) additional fixing at inclusion of transfer of a backing.

Section A-and


1 — the Sleeve 2 — the cam Roller 3 — the Cam 4 — the switching Lever

Apparently on section A-and, a sleeve (1) and the roller (2) cams are equipped with cuts, and, the end of the lever of switching (11) settles down between them (on an illustration the lever is shown in the neutral provision of a box). Extreme left position of the lever corresponds to the choice of the 1st or 2nd transfer, extreme right - to the 5th and back transfers.

At inclusion of the 5th and back transfers the lever at the same time presses on the roller (2) therefore the cam (3) moves to the provision of the choice of the corresponding transfer. When the lever of switching ceases to wring out the roller, the cam comes back to a starting position under the influence of the effort developed by a spring (5).

In attempt of switching from the 5th transfer to back the lever (11) is displaced towards turning on of the reverse gear, wringing out the roller (2) and causing turning of a cam (3).

Type of Z


1 — the Sleeve 3 — the Cam 6 — the Persistent plate 7 — the Lock ring

The cam is equipped with the stopper resting against a plate (6) and preventing its undesirable movement. As a result the lever stops, having turned a cam only on some limited corner corresponding to the provision of neutral transfer to which it comes back under the influence of a spring (4).

At turning on of the reverse gear the lever moves to the relevant party, at the same time wringing out the roller (2) and a cam (3).