The transfer gearbox is rigidly attached to the gearbox housing.
The drive for the transfer gearbox is the differential case of the gearbox, on the external splines of whose body the drive shaft of the transfer gearbox is mounted.
The transfer gearbox is an angle reducer with two bevel gears.
The main parts of the transfer gearbox are the housing, the drive shaft, the propeller shaft drive shaft (output shaft), the idler shaft, which drives the right front wheel, the driving and driven bevel gears.
The transfer gearbox housing is cast from aluminium alloy and has two vertical joints, closed by the front and rear covers.
The transfer gearbox housing is secured to the clutch housing by three bolts and two nuts and is centred by two guide bushes pressed into the clutch housing.
On the right side, the transfer gearbox is secured by means of a bracket to the cylinder block and the engine sump.
The bracket is simultaneously secured to three parts in order to exclude its skewing during installation of the transfer gearbox and the appearance of internal stresses in it.
In the opening for securing the bracket to the engine sump, a floating split bush is installed.
To secure the bracket to the cylinder block and the engine sump, special bolts with a centring collar are used.
When installing the transfer gearbox, the external splines of the hollow drive shaft connect with the splines of the differential case installed in the gearbox, and the splines of the right wheel drive — with the splines of the differential half-shaft gear.
Inside the transfer gearbox, on the splines of the drive shaft, the driving bevel gear of the hypoid transmission is rigidly secured, being in constant mesh with the driven gear.
The driven gear is made as one piece with the propeller shaft drive shaft (output shaft).
On the splines of this shaft, a flange is fitted, connecting the shaft to the flange of the cardan joint yoke, as a result of which the propeller shaft rotates constantly when the vehicle is moving.
The idler shaft is located inside the hollow drive shaft and connects with the body of the inner joint of the right wheel drive.
This connection is sealed by a rubber ring.
Transmission oil designed for the entire service life is poured into the transfer gearbox.
Sometimes the need to change the oil may arise when switching to an oil of a different viscosity, when repairing the transfer gearbox or when removing the right wheel drive.
It is also mandatory to change the oil after immersing the transfer gearbox in water.
The oil should be drained after a trip, when the oil is warmed up.
We pour into the transfer gearbox transmission oil API GL5 SAE75W-90 in the amount of 0.9 l.
The oil level should be at the edge of the control opening or slightly below (you can reach the oil surface with your finger).
If the level is greatly lowered, oil must be topped up with a syringe.
Possible transfer gearbox faults and remedies
Cause of fault — Remedy
Noise when the vehicle is moving:
- Loosening of the transfer gearbox mounting to the gearbox housing and to the engine oil sump — tighten the mounting or replace the mounts;
- Wear or damage to the gears and bearings — repair the transfer gearbox;
- Oil of an unsuitable grade has been poured in — pour in quality oil;
- Insufficient oil level — top up the oil to the norm.
Oil leakage:
- Destruction, damage to the oil seals — replace the oil seals.
