The front axle of the VAZ-2121 is combined.

It performs the functions of the driving and controlled axles simultaneously and has a permanent drive from the transfer case

The front axle of the car includes: a housing, a final drive, a differential and a front wheel drive.

The housing 4 of the front axle is made in the form of a one-piece housing with a developed middle part.

It is cast from cast iron.

Covers 1 and 21 are attached to the middle part of the housing.

On the sides of the housing there are special flanges for installing covers 29 of bearings 28 of the housings of the inner joints of the wheel drive, as well as for the front axle mounting brackets.

The final drive and differential are located inside the front axle housing.

Front axle: 1 - front cover; 2 - front cover gasket; 3 - front axle mounting stud; 4 - crankcase; 5 - final drive driven gear; 6 - satellite; 7 - half-shaft gear; 8 - satellite shaft; 9 - differential case; 10 - breather; 11 - pinion gear adjusting ring; 12 - pinion gear front bearing; 13 - pinion gear; 14 - pinion gear rear bearing; 15 - oil deflector; 16 - pinion gear oil seal; 17 - pinion gear flange; 18 - flange fastening nut; 19 - spacer sleeve; 20 - lower crankcase cover gasket; 21 - lower crankcase cover; 22 - filler plug; 23 - differential case bearing; 24 - left inner joint housing; 25 - inner joint housing bearing mounting ring; 26 - inner joint housing oil seal; 27 - retaining ring; 28 - inner joint housing bearing; 29 - inner joint housing bearing cover; 30 - differential case bearing adjusting nut; 31 - differential bearing cover fastening stud; 32 - differential case bearing cover; 33 – axle gear support washer

The main gear and front axle differential have the same design as the rear axle, and their parts are unified.

The axle gears are splined to the housings of the inner hinges of the front wheel drives.

Each of the two housings rests on a single-row ball bearing installed in the gearbox socket.

The bearings are covered with covers secured to three studs and sealed with cardboard gaskets.

The front axle bracket is attached to the gearbox together with the right cover.

A breather is pressed into the upper right part of the gearbox housing.

Possible front axle malfunctions, their causes and troubleshooting methods

Cause of malfunction - Method troubleshooting

Constant increased noise when operating the front axle

Worn or incorrectly adjusted differential bearings - Replace worn parts, adjust differential bearings

Incorrect adjustment, damage or wear of gears or bearings of the gearbox - Determine the malfunction of the gearbox, repair or replace the gearbox

Insufficient oil in the axle housing - Restore the oil level, check for oil leaks in the front axle housing seals

Worn or destroyed bearing of the inner joint housing - Replace the bearing

Noise when accelerating the car and braking with the engine

Incorrect adjustment of the engagement of the gears of the main gear - Adjust the engagement

Incorrect lateral clearance in the engagement of the gears of the main gear - Adjust clearance

Increased clearance in pinion bearings due to loose flange mounting nut or bearing wear - Adjust clearance, replace bearings if necessary

Knock when starting the vehicle

Worn hole for pinion shaft in differential case - Replace differential case and pinion shaft if necessary

Oil leak

Worn or damaged oil seal - Replace oil seal

Worn inner joint housing oil seal - Replace oil seal

Loose fastening of bearing cap of inner joint housing or crankcase covers, damage to sealing gaskets - Tighten nuts and bolts, replace sealing gaskets