9.3. Automatic transmission

General information
As the automatic transmission and system of hydraulic management are difficult devices and the special tool, certain knowledge, skills and experience are necessary for carrying out repair, works with the automatic transmission should be performed in a specialized workshop. For this reason of operation, provided in this subsection, are limited to area of the general diagnostics, the current maintenance and adjustments, removal and installation of the transmission. Also the description of replacement of epiploons entrance and power shafts is provided.
Capital repairs of the transmission need to be made in a specialized workshop. Nevertheless you can independently remove and install the transmission, thereby having reduced expenses even if further repair will be executed by the specialist in transmissions.
Adjustments which can be executed independently include works with the mechanism of inclusion of a low gear, the blocking switch (start-up from a neutral state), a vacuum diaphragm and draft of gear shifting.

Fig. 9.22. Automatic transmission: 1 – epiploon; 2 – vacuum diaphragm; 3 – the coil of the lowering transfer; 4 – blocking switch; 5 – oil pallet; 6 – oil pipeline; 7 – a stopper for determination of pressure of liquid; 8 – covers; 9 – clamp of the hydraulic booster; 10 – tube of check of level of working liquid; 11 – drain stopper; 12 – speedometer drive gear wheel


The basic external elements of the automatic transmission are shown in fig. 9.22.

Moments of an inhaling, N · m
Bolts of M10 of fastening of a cross-piece..... 44–55
Bolt of M12 of fastening of a cross-piece..... 95–118
Blocking switch..... 19–26
Bolt of fastening of the oil pallet..... 5–8
Bolts of fastening of the transmission to the engine..... 91–118

PREVENTION
Never tow the car with the automatic transmission at a speed more than 50 km/h or on distance more than 80 km (except for towage cases with the lifted driving wheels). Non-compliance with this requirement can lead to serious damages of the transmission which are caused by a lack of lubricant.

General diagnostics
Malfunctions of the automatic transmission can be caused by the following four reasons:
– unstable operation of the engine;
– wrong adjustment;
– malfunction of hydraulic system;
– malfunctions of mechanical elements.
Diagnostics of malfunctions always has to begin with check of easily repaired elements and parameters of adjustment, such as level of working liquid and its condition, adjustment of draft of gear shifting and draft of a butterfly valve. Then carry out road tests to define whether the problem was fixed or further diagnostics is required. If malfunction remains after completion of preliminary tests, additional diagnostics should be carried out in a specialized workshop.

Check and replacement of a vacuum diaphragm
Signs of damage of a vacuum diaphragm are vibrations when switching and incomplete inclusion of transfer.
Merge about 1 l of working liquid from a transmission case that its level was below a vacuum diaphragm.
Disconnect a vacuum hose and remove a vacuum diaphragm from a transmission case.

Fig. 9.23. Use of the vacuum pump for check of a vacuum diaphragm


Connect the vacuum pump to a diaphragm and check that the rod moved at depression (fig. 9.23). If the rod does not move or moves less than to 25 mm, replace a diaphragm.
Before installation grease with sealant a diaphragm carving.
After installation check the level of working liquid and add it as required.

Check and adjustment of the mechanism of compulsory inclusion of a low gear
If the transmission does not switch to a low gear when pressing against the stop of a pedal of an accelerator and the solenoid of inclusion of a low gear does not work properly, perhaps, the mechanism of inclusion of a low gear is faulty or demands adjustment.
Check.

Fig. 9.24. Check of the mechanism of inclusion of a low gear on lack of a gap


By pressing an accelerator pedal against the stop the ohmmeter connected according to the scheme shown in fig. 9.24 has to show lack of a rupture of a chain between contacts.
Adjustment.
Weaken a lock-nut and turn the mechanism of inclusion of a low gear until the ohmmeter does not show lack of a gap at the provision of a pedal of an accelerator on 7/8 full speeds. Tighten a lock-nut.

Check of the solenoid of inclusion of a low gear
Points lack of switching of the transmission to a low gear to damage to the solenoid of a low gear when pressing against the stop of an accelerator pedal either unstable or rough switching of transfer.
Lift a forward part of the car and reliably fix on supports. Merge about 1 l of working liquid from the transmission.
Track laying of a wire to the socket located about the rechargeable battery, and disconnect it.
Big flat-nose pliers turn out the switch and close an opening a rag.
You hold a finger on a solenoid plunger, fix the solenoid case on the negative plug of the rechargeable battery and, giving tension on contact of the switch from the positive plug of the battery, be convinced that the plunger of the solenoid is involved.
Replace the solenoid if there were any doubts concerning its state.
Before installation apply sealant on a solenoid carving.
After installation check the level of working liquid and fill it in case of need.

Check and replacement of the switch of blocking
Check
Check operation of the switch of blocking, having convinced that the engine is launched, only if the lever of the selector is in provisions "parking" or "neutral".
Track laying of a wire from the switch to the socket and disconnect the socket.
Measure by an ohmmeter resistance between switch plugs, it has to strive for infinity (gap) in provisions "backing", "parking" and "neutral".

Fig. 9.25. Arrangement of contacts of the switch of blocking


At the included ignition and the selector in noted provisions there should not be a gap between the following contacts (fig. 9.25):
– "And" and "In" (parking);
– "With" and "D" (backing);
– "And" and "In" (neutral).
Replacement
Switch-off the contact socket and turn out the blocking switch from a transmission case. Installation is carried out to the sequences, the return to removal. Before installation apply sealant on a switch carving.

Removal and installation of the transmission
Removal
Disconnect a wire from the negative plug of the rechargeable battery.
Disconnect a speedometer drive cable.
Disconnect a switching cable from the transmission.
Disconnect wires of connection with "weight" from the transmission.
Disconnect sockets from the switch of blocking and the solenoid of compulsory inclusion of a low gear.
Remove a starter.
There are two main ways of support of weight of the engine during removal of a cross-piece and the transmission. It is possible to use special adaptation which leans on suspension bracket support, or the winch for raising of the engine.
In case the device for support is used, install it first of all. If for raising of the engine the winch is used, for increase in working space previously remove a cowl.
Install the device for support of the engine and lift the car for providing sufficient distance for lowering of the transmission, reliably fix the car on supports.
Disconnect pipelines of the oil heater from the transmission.
Disconnect and fix all remained vacuum hoses and contact sockets which are switched-off from the transmission on a body.
Turn out the top bolt of fastening of the transmission to the engine.
Remove forward wheels and mudguards. Remove a protective plate of the oil pallet.
Disconnect the stabilizer of cross stability, turn out the lower bolts of fastening of the spherical hinge and a nut, separate spherical hinges.
Disconnect the left power shaft from the transmission and fix by a soft wire it on a body.
Remove an intermediate power shaft and assembly of a suspension bracket. Insert a wooden stopper or a similar cap for keeping on the place of satellites of differential.
For access to the hydrotransformer remove a plate and a dividing plate.
Ask the assistant to turn a bent shaft of the engine a wrench for a bolt of fastening of a pulley to establish it in situation at which access to bolts of fastening of the hydrotransformer is possible.
Turn out all bolts, except two of cross-piece knot.
Place a jack under a cross-piece, turn out bolts and lower a cross-piece.
Support by a jack through wooden whetstone the transmission.
Having convinced that the weight of the engine is perceived by the supporting adaptation, turn out two lower bolts of fastening of the transmission to the engine.
Take away the transmission from the engine and accurately take it from under the car.
Installation
Lift the transmission and attach to the engine, at the same time be convinced that the hydrotransformer was not displaced.
Screw bolts of fastening of the transmission to the engine and tighten them the required moment.
Establish an engine cross-piece.
Further installation is carried out to the sequences, the return to removal, taking into account the following.
Make sure that all nuts and bolts are tightened by the required moments.
Check the level of working liquid.

Replacement of epiploons of the transmission
Epiploon of an entrance shaft
Remove the transmission.
Remove the hydrotransformer from an entrance shaft.
The small screw-driver or center punch take an old epiploon from a transmission case.
Oil working edges of an epiploon pure engine and press an epiploon in an opening aflush with a case. Working edges of an epiploon have to be directed in a case.
Install the hydrotransformer.
Install the transmission.
Epiploons of power shafts
Disconnect the left power shaft or an intermediate power shaft. Insert a wooden stopper or a similar cap for keeping on the place of satellites of differential. Do not allow hit of dirt in the transmission.
The screw-driver take an old epiploon from a transmission case.
Oil working edges of an epiploon pure or lubricant of white color on a lithium basis. A tubular mandrel with a diameter of 45 mm press an epiploon in an opening. Working edges of an epiploon have to be directed in a case.
Establish the left power shaft or an intermediate power shaft.

Check and adjustment of a cable of gear shifting

Fig. 9.26. Provisions of fixing of draft of gear shifting


Install the selector lever consistently in each situation and be convinced that it is fixed in each situation and corresponds to a plate of the switch (fig. 9.26). At inclusion of each situation small resistance has to be felt.
The lever of the selector has to move between provisions "movement" and "neutral" without pressing of the button on the selector handle. The button needs to be pressed when moving the lever of the selector from situation "movement" in situation "backing".

Fig. 9.27. Details of the lever of the selector and cable of gear shifting: 1 – a pin of fastening of a cable to the transmission; 2 – cable of the switch of transfers; 3 – bolt of fastening of the lever; 4 – button; 5 – button lock-nut; 6 – pusher; 7 – selector lever; 8 – the directing pin; 9 – cable lock-nut; 10 – selector lever suspension bracket; 11 – nut and washer


If the button is too free or the switch can be moved from situation "movement" to situation "backing" without pressing of the button, adjust the switch button. Weaken a lock-nut and wrap the lever button until the required functioning of a cable of switching is reached; then tighten a lock-nut (fig. 9.27).

Replacement of laying of the oil pallet
Merge working liquid from the transmission.

PREVENTION
Be careful – liquid can be very hot.

Turn out bolts of fastening of the oil pallet and remove the pallet, at the same time be prepared for possible course of liquid.
Remove the remains of old laying from a case of the transmission and the oil pallet, at the same time be attentive not to damage privalochny surfaces and to exclude hit of dirt in a transmission case.
Establish new laying on a transmission case, previously apply on it a layer of pure lubricant for keeping of laying in the correct arrangement.
Install the oil pallet and fix by bolts, having tightened them the required moment.
Screw a drain stopper, fill the transmission with fresh working liquid.
Check the transmission for lack of leaks.