4.3. Transfer case

POSSIBLE MALFUNCTIONS OF THE TRANSFER CASE, THEIR REASON AND METHODS OF ELIMINATION
DRIVESHAFTS
POSSIBLE MALFUNCTIONS OF DRIVESHAFTS, THEIR REASONS AND METHODS OF ELIMINATION




Fig. 3.49. Distributing box: 1 – leading shaft (secondary shaft of a box of transfers); 2 – bearing of the leading shaft (secondary shaft of a box of transfers); 3 – a gear wheel the leader (a gear wheel of inclusion of a straight line and lowering transfers); 4, 7 – bearings of a shaft of the drive of the back bridge; 5 – the gear wheel conducted a speedometer; 6 – gear wheel leading speedometer; 8, 21 – cuffs; 9, 22 – flanges; 10 – shaft of the drive of the back bridge; 11, 23 – bearings of an intermediate shaft; 12 – intermediate shaft; 13 – gear wheel of inclusion of forward and back bridges; 14 – covers of bearings; 15 – shaft of the drive of the forward bridge; 16, 20 – bearings of a shaft of the drive of the forward bridge; 17 – case cover; 18 – case; 19 – stopper of a drain opening; 24 – cap; 25 – suspension bracket plate; 26 – glass persistent bearing; 27 – hatch cover; 28 – switching mechanism cover; 29 – a rod of a fork of inclusion of a straight line and lowering transfers;
30 – rod of a fork of inclusion of the forward bridge; 31 – clamp ball; 32 – clamp spring;
33 – fork of inclusion of the forward bridge; 34 – a fork of inclusion of a straight line and lowering transfers


The transfer case two-level, mechanical, has the additional lowering transfer (fig. 3.49).
On a part of cars the upgraded "melkomodulny" transfer case in which teeths of a gear wheel of inclusion of forward and back bridges, and also gear wreaths of shaft of the drive of back and forward bridges are executed with the module of 2,5 mm can be installed (instead of 3,5). At the same time the transfer number of the lowest transfer decreased and became 1,47 (instead of 1,94).
Transfer cases are interchanged and externally differ in nothing.
The changed details differ from similar details with the module of teeths of 3,5 mm in number of teeths (tab. 3.2).

Maintenance
In use check the level of oil and replace it in the terms provided by the table of greasing. Periodically check all fastenings. At detection of a leak find out the reason and replace faulty details (laying, cuffs, caps, etc.).
In use cars lowering of the level of oil in the transmission to 8 mm of rather lower edge of a jellied opening and its simultaneous increase in the transfer case is possible. At the same time it is not obligatory to level oil levels in the transmission and the transfer case as the total amount of oil ensures normal functioning of both knots.
When changing oil in a case of the transfer case or its dolivka it is necessary to bring at the same time oil level as well in the transmission to bottom edge of a jellied opening.
On family cars UAZ – 31512 grease an axis of levers of switching through a press butterdish. Access to it – from below.
On family cars UAZ – 3741 when dismantling the mechanism of management grease shaft and the lower support, and also you make adjustment of forward drafts of the mechanism.
The transfer case of adjustments has no.

Repair
 Dismantling of the transfer case
You make dismantling of the transfer case in the following order:
1. Turn off nuts and bolts of fastening of the transfer case to the transmission and separate knots. Take out a persistent ring of an intermediate shaft of the transmission from a nest. Remove laying from the interfaced end faces.
2. Uncover the hatch of selection of power.
3. Uncover the switching mechanism with rods and levers.
4. Turn out screws and remove a drum of the parking brake mechanism.
5. Turn off a nut of a flange of a shaft of the drive of the back bridge and remove a flange.
6. Turn off bolts of fastening of the brake mechanism to the transfer case and remove it.
7. Remove a flange from a shaft of the drive of the forward bridge and a cover of the forward bearing of this shaft with a cuff.
8. Turn off bolts of connection of parts of a case and separate a case so that all internal details remained on a cover. Do not take out caps and a glass of the bearing without emergency.

Fig. 3.50. Knocking-out of rods and removal of forks


9. Remove a lock plate of rods of switching and beat out rods (fig. 3.50) the copper hammer, having at the same time removed from them switching forks.
At the same time hold balls and springs of clamps which are in nests of forks from loss.

Fig. 3.51. Removal of a gear wheel of a speedometer


10. Remove a stopper of the union of the conducted gear wheel (fig. 3.51) of a speedometer and take out a gear wheel together with the union.

Fig. 3.52. Removal of lock rings of bearings


Fig. 3.53. Vypressovka shaft of a distributing box


11. Uncover bearings of an intermediate shaft and shaft of the drive of the forward bridge. Remove lock rings (fig. 3.52) of bearings and beat out shaft (fig. 3.53).

Fig. 3.54. Removal of the bearing from a shaft of the drive of the back bridge


12. Remove a stripper bearings (fig. 3.54) from shaft.
13. Vypressuyte shaft of the drive of the back bridge. Remove from it a maslootrazhatel, the leading gear wheel of a speedometer and remove a stripper the bearing.
14. Uncover the back bearing of a shaft of the drive of the back bridge and take out the bearing.
15. * Turn off a nut of axes of levers, a vypressuyta and remove levers.
16. * Remove an arm of levers.

* On cars of family UAZ-3741 instead of works on subitems 15, 16 it is necessary to remove shaft of management

Fig. 3.55. Dismantling of the mechanism of switching


17. Beat out five caps from a switching mechanism cover. Beat out pins (fig. 3.55) from levers towards the removed caps.
18. Take out a rod of inclusion of the forward bridge, a lock ball through a side opening, a rod of inclusion of a straight line and lowering transfers.

Fig. 3.56. Removal of an internal ring of the roller bearing of an intermediate shaft


Note
Till March, 1993 on an intermediate shaft of the transfer case the internal ring of the roller bearing (fig. 3.56) napressovyvatsya, and till July, 1994 the nut of fastening of a shaft was established.

 Assessment of technical condition of details
After dismantling carefully wash out all details of the transfer case in kerosene, blow compressed air and examine.
At the same time pay attention to the following.
Case of the transfer case and its cover. External survey reveal cracks, chips, breaks, having paid special attention to ears of fastening of a case and cover, a condition of a carving in openings, absence забоин and agnails on the condensed surfaces.
Replace the case and a cover having cracks, chips, breaks. Eliminate minor defects. Keep in mind that the case and a cover of the transfer case are processed in common and therefore are not interchangeable at different transfer cases.
Gear wheels. On teeths should not be having chopped off and забоин. The side surface of teeths should not have traces of a vykrashivaniye and a smyatiya, on face surfaces of gear wheels there should not be zadir. Landing surfaces should not have the damages and wear breaking centering of details. Replace worn-out gear wheels.
Shaft of the transfer case should not have damages of a carving.
Vents of a shaft should not have zadir, agnails, забоин, deep a smyatiya of side surfaces. Replace worn-out shaft.
Flanges of driveshafts should not have width of hollows of shliyets more than 4,645 mm.
Bearings should not have damages of separators, cracks and chips of rings and a vykrashivaniye of racetracks, and also notable radial and axial gaps. Replace worn-out bearings.
Cuffs should not have gaps, vyryv and cracks on the working surface and deformation of fittings. The strip of wear of a working edge should not be more than 2 mm. Replace worn-out cuffs.
Forks of switching should not have cracks, curvature and big wear. Replace worn-out details.
Rods of the mechanism of switching have to have reliably priklepanny fingers.

Assembly of the transfer case
You make assembly of the transfer case from subassembly of its knots.
 Assembly of a case
1. Press a persistent glass of the bearing of the leading shaft in a case against the stop (if he acted).

Fig. 3.57. A press fitting of the roller bearing in a case


2. Press the roller bearing in a case (fig. 3.57), having sustained the size of 6-0,5 mm from a case end face.
3. Screw masloslivny and oil-filling traffic jams.
4. Insert also to a raschekanta a cap of the bearing of an intermediate shaft.
 Assembly of covers
1. Press a cuff in a cover against the stop.
2. Fill a cavity between working edges of a cuff Litol-24 lubricant.
 Assembly of a shaft of the drive of the back bridge

Fig. 3.58. Napressovka the bearing on a shaft at - water of the back bridge


Napressuyte on a shaft the bearing against the stop (fig. 3.58).
 Assembly of an intermediate shaft
1. Napressuyte on a shaft a ring of the roller bearing (if it is provided by a design).
2. Pick up a gear wheel of inclusion of the forward bridge for shaft vents with the minimum gap at its free movement on a shaft.
3. Napressuyte on the back end of a shaft the bearing so that the flute for a persistent ring was displaced outside.

Fig. 3.70. Latching of a nut a bend of its edge in a groove of a shaft and a profile of the tool:
And – the place of latching; B – a tool profile


4. Establish a lock ring. On a box of an old design tighten a nut of fastening of a shaft to the full and stop its bend edges in a shaft groove. Use to a zagibka only the tool with the rounded-off edges (see fig. 3.70).

Fig. 3.59. An intermediate shaft in collecting


The intermediate shaft is assembled shown in fig. 3.59.
 Assembly of a shaft of the drive of the forward bridge
1. Napressuyte on a shaft the bearing from a gear wheel so that the flute for a lock ring was displaced towards a nut.

Fig. 3.60. A shaft of the drive of the forward bridge in collecting


2. Tighten a nut and stop its bend edges in a shaft groove (see fig. 3.70). Use to a zagibka only the tool with the rounded-off edges. The shaft of the drive of the forward bridge is assembled shown in fig. 3.60.
 Assembly of a cover of the mechanism of switching of the transfer case

Fig. 3.61. The mechanism of switching of cars of family UAZ-31512 in the sorted look: 1 – the lever of inclusion of a straight line and lowering transfers; 2 – flat springs; 3 – lever of inclusion of the forward bridge; 4 – washer; 5 – arm;
6 – nut; 7 – cover; 8 – caps; 9 – a ball of a rod of inclusion of the lowering transfer; 10 – laying; 11 – rod of inclusion of the forward bridge; 12 – rubber rings; 13 – a rod of inclusion of a straight line and lowering transfers; 14 – lead of inclusion of the forward bridge; 15 – a lead of inclusion of a straight line and lowering transfers; 16 – pins; 17 – axis of levers;
18 – press-butterdish


The mechanism of switching (in unassembled form) is shown in fig. 3.61.
1. Put rubber rings in cover openings for rods.
2. Insert a rod of inclusion of a straight line into a cover and lowering transfers (it has an oblong lyska), at the same time putting on it the lever with a short nave.
3. Enclose in a cover through a side opening a lock ball with a diameter of 11 mm.
4. Insert a rod of inclusion of the forward bridge (it has a semicircular flute) into a cover, at the same time putting on it the lever with a long nave.

Fig. 3.62. Installation of pins in switching mechanism levers


5. Insert pins (fig. 3.62) through the top openings in a cover and kill them aflush, having fixed levers on rods.
External fingers on rods arrange in different directions, and levers – the planes to each other.

Fig. 3.63. Raschekanka of caps of otvers-tiya of rods


6. Insert also to a cap raschekanta a mandrel (fig. 3.63).
7. * Establish on a cover a stamped arm 5 (see fig. 3.61) levers and fix it by three bolts with spring washers.
8. * Grease an axis of levers with Litol-24 lubricant and insert it into an arm, putting on an axis consistently polyethylene washer, the lever of inclusion of a straight line and lowering transfers, two flat springs, the lever of inclusion of the forward bridge and a polyethylene washer. At the same time forks of the lower ends of levers have to enter gearing with fingers of rods, and flat springs to clasp cores of levers.
9. * Establish a spring washer on an axis and tighten a nut to the full.
10. * Screw in an axis a press butterdish so that its nose was turned to the cover socket plane.
11. * Screw handles on levers.

* For cars of family UAZ-31512
Assembly of shaft of management of cars of family UAZ-3741

Fig. 3.64. Mechanism of control of the transfer case of cars of family UAZ-3741:
1 – lever of inclusion of the forward bridge; 2 – the lever of inclusion of a straight line and lowering transfers; 3 – adjusting forks; 4 – lock-nuts; 5 – forward drafts; 6 – plugs; 7 – lock screw; 8 – splines;
9 – arm; 10, 11 – the intermediate lever; 12 – nut; 13 – hinged bearing; 14 – bearing case; 15 – switching shaft; 16 – back drafts


The mechanism of control of the transfer case is shown in fig. 3.64.
1. Establish a rubber cuff on the spherical end of a shaft of inclusion of the forward bridge, grease the sphere with graphitic lubricant and establish two crackers.
2. Put graphitic lubricant in a support of shaft and insert a shaft with crackers into an arm nest.

Fig. 3.65. Installation of a lock ring of crackers


3. Stop crackers (fig. 3.65) a spring lock ring and close a rubber cuff.

Fig. 3.66. Shaft of management of a distributing box of cars of family UAZ-3741 in collecting



4. Establish a polyethylene washer (fig. 3.66) and a tubular shaft of inclusion of the back bridge on a shaft of management.
 Assembly of the transfer case from subcollected knots
You make further assembly of the transfer case in the following order:

Fig. 3.67. The shaft of the drive of the forward bridge established in a case cover


1. Insert a collected shaft of the drive of the forward bridge into the lower opening of a cover of a case, put a persistent ring in a bearing flute and establish a shaft against the stop (fig. 3.67).

Fig. 3.68. The shaft of the drive of forward and back bridges established in a case cover


2. Insert a collected shaft (fig. 3.68) of the drive of the back bridge into the top opening of a cover of a case.
3. Oil gearbox teeths of the leading gear wheel of a speedometer, put on a gear wheel a shaft of the drive of the back bridge, put on a shaft a maslootrazhatel and a napressuyta the bearing with a persistent ring against the stop.

Fig. 3.69. The shaft of a distributing box established in a case cover


4. Insert a collected intermediate shaft into an average opening of a cover of a case, put on a persistent ring the bearing and establish a shaft against the stop (fig. 3.69).
5. Establish covers of bearings and fix them by bolts with spring washers.
6. Install the parking brake mechanism on a cover of the bearing of a shaft of the drive of the back bridge.
7. Put on a flange, a washer vents of a shaft of the drive of the back bridge, tighten a nut to the full and stop its bend edges in a shaft groove by means of a center punch, as shown in fig. 3.70.
8. Insert the rod having two flutes into a case cover opening so that the copperplated end of a rod was outside. Insert a fork of inclusion of the forward bridge (wide and short) into a groove of a gear wheel of inclusion of forward and back bridges. Insert a spring and a ball of a clamp into a fork nest.
9. Insert a rod into a fork, squeezing a clamp spring. Press the copperplated end of a rod in a case cover to a flute.
10. Put on a fork of inclusion of a straight line and lowering transfers on a rod with three flutes. Press a rod the copperplated end in a case cover to a flute.
11. Put a lock plate in flutes of rods and fix it by a bolt with a spring washer.
12. Enclose in a fork a gear wheel of inclusion of a straight line and lowering transfers and include it (together with a fork) in the provision of direct transfer.
13. Establish in the case of a gear wheel and shaft collected on a cover, connect a case to a cover and wrap bolts with spring washers.

Fig. 3.71. Installation of a cover of the forward bearing of a shaft of the drive of the forward bridge


14. To Napressuyta on a shaft of the drive of the forward bridge the bearing, establish laying, close the bearing a cover with a cuff (fig. 3.71). Fix a cover by bolts with spring washers.
15. Put on a flange, a washer vents of a shaft of the drive of the forward bridge, tighten a nut to the full and stop it, having bent a nut edge in a shaft groove.
16. Grease a neck and teeths of the conducted speedometer gear wheel with gearbox oil. Put on the union a gear wheel and insert it into an opening of a cover of the transfer case. Stop the union a lock plate and a bolt with a spring washer.
17. Establish laying of a cover of the mechanism of switching to the case socket, establish a cover with levers and rods so that levers entered grooves of the corresponding forks and fix it by bolts with spring washers.
18. Install laying on the socket of the hatch of selection of power, close the socket a cover and fix a cover by bolts with spring washers. Establish a cover by the convex party of a stamping polygon outside.
 Assembly of the transfer case with the transmission
You make assembly of the transfer case with the transmission in the following order:
1. Include the II transfer in the transmission.
2. Enter the leading gear wheel of the transfer case into gearing with shaft of the drive of the back bridge.
3. Install the transfer case on a drum of the parking brake mechanism by a flange up.

Fig. 3.72. Distributing box with sealing laying


4. Establish sealing laying (fig. 3.72) on the transfer case.

Fig. 3.73. Distributing box with a suspension bracket plate, persistent ring and laying


5. Establish a plate of a suspension bracket (fig. 3.73) on the transfer case and press to laying.
6. Establish a persistent ring of the bearing of an intermediate shaft of the transmission in a nest of the transfer case.
7. Put laying on a plate.

Fig. 3.74. Connection of a box of transfers with a distributing box


8. Install the transmission (fig. 3.74) on the transfer case so that openings for hairpins and bolts coincided. Turning a main shaft of the transmission, combine vents of a secondary shaft of the transmission with vents of the leading gear wheel of the transfer case and besiege the transmission down.
Establish spring washers under nuts and heads of bolts and, evenly tightening nuts and bolts, connect the transmission to the transfer case.
9. Check inclusion of all transfers in the transfer case, turning a hand shaft for the brake drum or a flange of a shaft of the drive of the forward bridge and for a main shaft of the transmission.
All transfers have to be fixed accurately by clamps in provisions of inclusion and neutral situation.
The lowering transfer has to join only after inclusion of the forward bridge.
At repair of the transfer case use these tab. 3.3.