The transfer case is mechanical, has two gears
Gear ratio 1st gear 2.08, 2nd gear 1.0
The transfer case is rigidly fastened with four bolts to the longitudinal beams of the frame, which, in turn, are attached to the brackets of the frame cross members on rubber cushions.
The gears of the transfer case are shifted with lever 1 (Fig. 3), which has three positions.
When the lever is in the rear position, the second (direct) gear is engaged, when the lever is in the forward position, the first (lower) gear is engaged, the middle position is neutral.
To prevent simultaneous engagement of two gears, a ball-type locking mechanism is used (see Fig. 1).
To facilitate driving in difficult off-road driving conditions, as well as to prevent transmission overload, the car has an electro-pneumatic front axle engagement control that automatically engages the front axle when first gear is engaged in the transfer case.
When the first gear of the transfer case is switched on, the switch 37 of the front axle, mounted on the rod 36 of the fork of the first (lower) gear, closes the electrical circuit of the electromagnet 1 (Fig. 3), which, pushing out the core 17, presses on the rod 10 of the air valve and opens it.
The air from the brake valve through the inlet valve 6 enters the diaphragm chamber 9. (Fig. 1), which acts directly on the rod 41 of the switching chamber of the sliding carriage 21.
This automatically engages the front axle drive.
When the first (lower) gear is turned off, the electromagnet circuit opens, the air valve closes, and the return 40 automatically turns off the front axle.
When the vehicle is moving (for example, on a slippery road), it may be necessary to engage the front axle in the second (direct) gear of the transfer case.
In this case, the electromagnet circuit that controls the front axle engagement can be forcibly closed using switch 11 (see Fig. 1) installed on the cab front shield (on the far right).
The left position of the switch knob corresponds to the on position of the front axle, the right position is off.
A switch 32 is installed on the rod of the front axle switching chamber (see Fig. 2), when it is closed, a control lamp lights up in the cab on the instrument panel.
The lamp lights up during automatic and forced engagement of the front axle.
At the top of the transfer box housing there is a hatch with a flange for attaching the power take-off.
Power take-off is carried out from gear 13 (see Fig. 1) of the input shaft of the transfer case.
In the hatch cover there is a breather 33 with an oil deflector, which prevents excess pressure in the transfer case as a result of temperature fluctuations.
A worm 19 of the speedometer drive is planted on the secondary shaft 18.
In the crankcase cover there is gear 26 of the speedometer drive. The speedometer drive consists of a five-start worm with five teeth and a gear with 17 teeth.
The gear ratio of the speedometer drive pair is 3.4.
Pour oil into the transfer case through the control-filler hole 7, closed with a stopper to the level of this hole.
The oil is drained through the drain hole, in the plug 24 of which a magnet is placed, which attracts metal particles that have fallen into the oil.
To prevent oil leakage from the transfer case, the exit points of all shafts are sealed with self-clamping rubber seals 12.
The front axle drive shaft seal, located below the level of the oil bath, is additionally protected by an oil slinger 6.
All joints of the transfer case crankcase, bearing caps and top hatch are sealed with a special paste.
For all work related to the disassembly of the transfer case, all parts of the crankcase should be put in place using the mentioned paste.
Transfer case care
During operation, it is necessary to check the reliability of fastening of the transfer case on the longitudinal beams of the frame and the reliability of fastening the beams themselves to the frame cross members; periodically it is necessary to tighten the mounting bolts.
It is also necessary to periodically flush and clean the air channels of the breather installed on the cover of the transfer case hatch, clogging of which can cause an increase in pressure in the transfer case crankcase; this can cause oil to leak through the stuffing box.
It is necessary to maintain a normal oil level in the box and change it in a timely manner according to the lubrication map.
When disassembling the transfer case, remember that the shaft end nuts are locked in the same way as on the gearbox.
When installing the air chamber of the front axle engagement carriage, it is necessary to adjust the size 174 ± 0.1 using shims 42, from the end of the chamber body 38 to the hole for the lock bolt on the shift rod in accordance with Fig. 2.