Service rear axle consists in periodically checking the oil level in the crankcase, refilling it and changing it according to the lubrication chart, cleaning the breather from dirt, tightening the drive pinion flange nut, axle shafts fastening nuts, checking and restoring the adjustments of the wheel hub bearings, pinion gear and differential.

The clearances in the final drive must be measured on the vehicle after disconnecting the propeller shaft. Before checking the clearances, it is necessary to check the tightness of the nut 1 of the flange of the drive gear (see), for which it is necessary to unpin the nut and tighten it with a torque of 160-200 Nm (16-20 kgfm). Check the clearances by moving the pinion flange in the axial and angular directions. The axial clearance in the drive gear bearings is checked as indicated in the subsection Adjusting the drive gear bearing preload).

To measure the total angular play of the drive gear flange, make a mark on the edge of the flange mud deflector, turn the flange all the way to the left and make a risk on the crankcase that matches the line on the reflector. Turn the flange all the way to the right and make the second notch on the crankcase. Measure the distance between the risks on the crankcase. If it exceeds 12 mm, it indicates excessive wear on the teeth of the drive and driven gears. main gear, differential gears or splines of side gears and side shafts.

Drain the oil from the rear axle housing after it has been preheated. Checking the oil level and refilling it is carried out through the crankcase filler hole on a car standing on a horizontal platform. The check should be done some time after the ride to allow the oil to cool and drain off the crankcase walls. Too little or too much oil is equally harmful.

If the bridge noise is so high that it is considered unacceptable from a comfort point of view or causes a fear of breakage, it is considered a malfunction. Axle “howling” (high-pitched noise) affects comfort and can be avoided by avoiding long driving in the narrow speed ranges at which it is heard. Before disassembling the bridge, make sure that the noise is coming from the bridge. Sources of noise can be a faulty clutch disc, tires (noise varies with different road surfaces and increases with increasing speed), engine.

... and press it in (you can use the outer ring of an old bearing as a mandrel).
We press the outer ring of the rear bearing into the crankcase with the same drift that knocked it out. This must be done carefully, making sure that the ring does not warp.

Install the inner ring with cage and rollers front bearing.
Having covered the seat and the working edge of the new oil seal with Litol-24 grease ...

... install the oil seal in the throat of the rear axle housing.

We press in the new oil seal one level with the end face of the crankcase neck, using the old oil seal as a mandrel.
If it was necessary to replace both bearings or the drive gear of the main gear of the rear axle on a Volga GAZ 31105 car, then it is necessary to adjust the position of the drive gear by selecting an adjusting ring and adjust the preload of the bearings (i.e., the axial play of the shaft). To adjust the position of the driving gear of the rear axle, you need a special mandrel made from an old driving gear and a cylindrical mandrel of a calibrated diameter. Such an adjustment (with the required precision) is difficult to carry out outside a specialized workshop. Therefore, you should assemble the rear axle gearbox with the adjusting ring, which was installed earlier, and select a new ring, focusing on the contact patch in the engagement of the main gears (see "Adjusting the rear axle gearbox according to the tooth contact patch"). Having adjusted the position of the drive gear, we measure the axial play of the drive gear shaft (see the measurement of the play above).
If the backlash is greater than the norm, measure the thickness of the old adjusting washer with a micrometer and select a new one (see "Design Description"). The new washer should be thinner than the old one by the amount of backlash and another 0.05 mm if the bearings of the rear axle drive gear were replaced with new ones, or by 0.01 mm if the bearings remained the same. Having installed the drive gear in the gearbox housing, tighten the flange nut with a torque of 160-200 Nm with a torque wrench (see "Replacing the rear axle gearbox oil seal"), while the gear must be turned to correct installation rollers in bearings.
If the washer is selected correctly, the torque of resistance to rotation of the drive gear shaft should be 1.5-2.5 Nm for new bearings or 0.7-1.0 Nm for worn-in bearings. With sufficient accuracy, the moment of resistance to rotation can be estimated by a steelyard ...

... by hooking it into the hole in the rear axle gearbox flange.
In this case, the values \u200b\u200bof the efforts on the balance wheel should be 3.8-5 kgf and 1.8-2.5 kgf, respectively. If the moment of resistance is greater, it is necessary to replace the adjusting washer with another one, 0.01-0.02 mm thicker, if it is less, choose a washer of a smaller thickness. We press the differential bearings through a piece of pipe of a suitable size, acting only on their inner rings. The bolts of the driven gear, as well as their nuts, are degreased and covered with an anaerobic sealant before assembly. We pay special attention to the cleanliness of the end surfaces of the gear wheel and the differential housing, the slightest dirt or nicks are unacceptable.
We remove the existing damage with fine abrasive emery paper, and then rinse thoroughly.
At the end of the assembly of the differential, we make sure that the backlash of the side gears is normal (see above). The half-axle gears should rotate easily by hand. With an increased clearance, we replace the washers of the side gears with others - of greater thickness.
By applying to the differential bearings transmission oil, we install the differential in the bores of the rear axle housing and fasten it with covers with bearing adjusting nuts (finally, without tightening the cover bolts).

With adjusting nuts, we tighten the differential bearings with a slight interference, while turning the gears so that the bearing rollers take the correct position.

To measure the lateral clearance in the meshing of the main gears on the rear axle housing, we fix the indicator by bringing its probe to the top of the tooth on the outside of the driven gear.
The gap should be 0.15-0.20 mm. The measurements should be repeated on at least six teeth in opposite areas of the rim. To reduce the gap (with a screwdriver or a thin steel rod), loosen the adjusting nut on the side opposite to the driven gear, and tighten the other.
Unscrew one nut and tighten the other by the same amount, focusing on the grooves of the adjusting nuts. In this case, each unscrewing of the adjusting nut must be completed by slightly screwing it in (for example, in order to loosen the nut by five slots, unscrew it by six, and then wrap it one slot). This will ensure that the outer ring of the bearing is in constant contact with the nut, thereby ensuring that it is secured during operation.
To increase the gap, perform the entire procedure in reverse order.
After adjusting the lateral engagement play, we check the axial play in the differential bearings (bearing preload).
For this...

... we fix the indicator on the tripod, resting its probe against the end of the driven gear of the rear axle. Swinging the gear in the axial direction, we measure the backlash in the bearings of the rear axle differential.

Using the adjusting nut located on the opposite side of the driven gear, we set the axial play of 0.035-0.055 mm.
Further, tightening the nut, we set the backlash: 0.1 mm - when the rear axle bearings run on the Volga GAZ 31105 car up to 10 thousand km; 0.05 mm - with a Volga GAZ 31105 car mileage of more than 10 thousand km. Turning the nut one slot corresponds to the bearing preload by 0.03 mm. Having adjusted the backlash, tighten the bearing cap bolts and, after installing the locking plates, check the side clearance again.

ATTENTION
Before the final tightening of the cover bolts, turn them out one by one and apply anaerobic sealant to the threads.

After assembling the rear axle of the Volga GAZ 31105 car, pour oil into the rear axle and test the gearbox on the go. To do this, we make a trip by car Volga GAZ 31105 at a speed of 60-70 km / h for 20-30 minutes. Heating of the throat of the rear axle housing should not be higher than 95 ° (water droplets should not boil). Otherwise, it is necessary to reduce the preload of the pinion bearings.

The rear axle bearings, side clearance and the position of the contact patch in the meshing of the main pair are adjusted at the factory and, as a rule, do not require adjustment during operation. Their adjustment is necessary only after the axle bulkhead and replacement of parts, as well as when the bearings are heavily worn. The lateral clearance in the engagement of the main gear, which has increased due to wear of the teeth, is not reduced by adjustment, since this leads to a disruption of the engagement and, as a result, to increased noise of the rear axle or to breakage of the teeth. Backlash in tapered bearings is eliminated without disturbing the mutual position of the driven and driving gears.

Adjusting the drive pinion bearing preload

The need for bearing adjustment can be determined by the presence of axial play in the pinion gear. Axial play is measured with disconnected cardan shaft using an indicator with a graduation of not more than 0.01 mm when moving the flange in the axial direction. In this case, the indicator foot should rest against the flange end parallel to the pinion gear axis.

The axial play in the pinion bearings should be eliminated by adjusting the preload. The preload is adjusted by selecting the thickness of the adjusting ring 5 (see).

The adjustment must be done as follows:

Loosen the cotter pin and unscrew the nut 1, remove the flange 2, the oil seal 3 and the inner ring of the bearing 4;

Replace the adjusting ring 5 with a new one, the thickness of which must be less than the one being replaced by the value of the axial play plus an additional 0.05 mm when the vehicle has run less than 1000 km or 0.01 mm when the car has traveled more than 10000 km;

Replace the inner bearing ring, a new oil seal, flange and tighten the nut to a torque of 160-200 N · m (16-20 kgf · m), then check the ease of rotation of the drive gear. If more force is required to rotate the drive gear than it was before the adjustment, then it is necessary to replace the adjusting ring, increasing its thickness by 0.01-0.02 mm.

After finishing adjustment of the bearing preload, tighten the nut to a torque of 160-200 Nm (16-20 kgfm) until the slot in the nut coincides with the hole for the cotter pin. The nut must only be tightened to match the hole for the cotter pin with the slot of the nut, since otherwise, due to insufficient tightening, the inner ring of the outer bearing may turn, wear the adjusting ring and, as a result, increase the axial play of the bearings. When tightening the flange nut, it is necessary to turn the drive gear to correctly install the rollers in the bearings.

After adjustment, it is necessary to check the heating of the bearings after the vehicle has been moving at a speed of 60-70 km / h for 20-30 minutes. In this case, the heating of the crankcase neck should not exceed 95 ° C (water that gets on the neck should not boil). Reduce the preload if it gets too hot.

Adjust the preload when replacing the bearings of the drive gear and the main gear in the following order:

It is necessary to adjust the position of the drive gear by selecting the adjusting ring 7 (see), ensuring the size (109.5 ± 0.02) mm - the distance between the common axis of the half-axle gears and the end of the drive gear adjacent to the adjusting ring 7;

By selecting the adjusting ring 5, adjust the bearing preload of the drive gear. When correct adjustment the moment of resistance to the rotation of the drive gear should be in the range of 150-200 Nm (15-10 kgfcm) for new bearings or 70-100 Nm (7-10 kgfcm) for operating bearings. If the moment of resistance to the rotation of the bearings is within the normal range, the nut must be pinned, otherwise the adjustment must be repeated. In this case, if the torque of resistance to rotation is less than the required one, it is necessary to reduce the thickness of the adjusting ring, and if it is more, it is necessary to choose a ring of greater thickness.

After adjusting the preload of the bearings, it is necessary to install the differential assembly in the axle and adjust the preload of the differential bearings and the lateral clearance in the meshing of the main gears.

Adjustment of differential bearing preload and lateral clearance in the meshing of gears and final drive

Adjustment without bearing replacement.

Remove the axle shafts and remove the gearbox from the axle housing (for a rear axle with a banjo beam);

With removed lock plates 14 (see) and loose covers 17 of the differential bearings with adjusting nuts 16, set the axial clearance of 0.01 mm in the differential bearings (see)

Install the indicator, as shown on, and check the lateral clearance in the meshing of the gears, which should be within 0.15-0.25 mm. Check at least six points, each time turning the gear;

To increase the lateral clearance, loosen the adjusting nut on the side of the driven gear and tighten the opposite nut by the same number of slots. To reduce the lateral clearance, these operations are performed in reverse order;

Adjust the preload value by compressing the bearings in the axial direction:

0.1 mm when the vehicle has traveled less than 1000 km;

By 0.05 mm with a run of more than 10,000 km;

Control by the angle of rotation of the adjusting nut. Turning one nut towards the other by the width of the groove corresponds to the compression of the bearings by 0.05 mm;

Tighten the bolts of the differential bearing caps and check the lateral backlash of the teeth of the main gear teeth;

Bolt the locking plates to the bearing caps;

Install the gearbox in the axle housing;

Install the axle shafts.

Adjustment when replacing bearings.

To adjust the bearings you need:

Remove the axle shafts, crankcase cover and cover gasket (for one-piece rear axle);

Remove the axle shafts and remove the gearbox from the crankcase (for a rear axle with a banjo beam);

Unscrew the bolts securing the covers, remove the covers, remove the differential and adjusting nuts 16;

Measure with a dynamometer the residual friction moment of the drive gear bearings;

Press out the inner bearing rings from the differential box and press on new ones;

Replace the differential with new bearings, tightly tightening their outer rings;

Insert the adjusting nuts 16 into the threaded part of the rear axle housing, as close as possible to the bearings, and install the covers 17 according to the existing markings on the bearing caps and on the rear axle housing;

Fasten the bearing caps with bolts with a force that does not prevent the tightening of the adjusting nuts 16 (the holes in the crankcase for the bolts must first be lubricated with anaerobic sealant);

Tighten the bearings with the adjusting nuts until a slight preload is obtained. While pressing the bearings, the driven gear must be rotated several revolutions in one direction, then in the other direction for the correct installation of the rollers in the bearings;

By alternately tightening the adjusting nuts of the differential bearings, to increase the torque of resistance to rotation of the drive gear by 150-300 Nm (15-30 kgfcm) relative to the residual torque of resistance to rotation, measured after removing the differential;

Install the indicator, as shown on, and check the lateral clearance in the meshing of the gears, which should be within 0.15-0.25 mm. To increase the clearance, loosen the adjusting nut on the driven gear side and screw the nut on the drive gear side the same number of slots to maintain the bearing preload. To reduce the lateral clearance, these operations are performed in reverse order;

The rotation of the adjusting nuts must be completed by tightening. For example, if you want to loosen the nut one slot, then release it by two, and then tighten one slot. This guarantees the contact of the nut with the outer ring of the bearing and the absence of displacement of the ring during operation;

Finally tighten the bearing cap bolts, bolt the locking plates on the bearing caps;

Install the gasket and rear cover (for one-piece rear axle);

Install the gearbox in the axle housing (for a rear axle with a banjo beam);

Install the axle shafts.

Checking the engagement by the contact patch

After final assembly and adjustment of the axle gearbox, check the gearing of the gears. To do this, you need to paint the teeth with paint. It should be noted that a very liquid paint spreads and stains the surface of the teeth, too thick - it is not squeezed out of the gaps between the teeth. Braking the driven gear, rotate the drive gear in both directions until a clear contact patch is indicated.

Figure: 5.35. Contact spot of the final drive gears: I - side forward motion (working); II - reverse side; 1 - correct contact in the meshing of the main gears at low load; 2 - contact at the top of the tooth (for correction, the drive gear is moved to the driven gear); 3 - contact at the root of the tooth (for correction, the drive gear is moved away from the driven); 4 - contact at the narrow end of the tooth (for correction, the driven gear is moved away from the leading one; 5 - contact at the wide end of the tooth (for correction, the driven gear is moved to the leading)

Obtaining the correct contact patch of the teeth completes the check of the installation of the gears and the lateral clearance in the engagement. The side clearance must be within the above limits. In fig. 5.35

2. To increase the lateral clearance, the driven gear is retracted from the driving gear:

On the working side of the tooth, the contact patch moves slightly higher and closer to the wide end of the tooth;

On the non-working side of the tooth, the contact patch moves slightly above and closer to the wide end of the tooth;

3. When the drive gear approaches the driven gear:

The contact patch on the working side moves below and closer to the narrow end of the tooth;

The contact patch on the non-working side moves lower and closer to the wide end of the tooth;

4. When moving the drive gear away from the driven gear:

The contact patch on the working side of the tooth moves to the apex of the tooth and to its wide end;

On the non-working side of the tooth, the contact patch moves towards the apex of the tooth and moves slightly towards its narrow end.

We carry out work on the repair of the rear axle of the Volga GAZ 31105 car on an inspection pit or overpass, without removing the rear axle from the GAZ 31105 car. Disconnect from the rear axle cardan shaft... We clean the rear axle from dirt, wipe it with a rag. Drain the oil from the rear axle housing. We take out the axle shafts from the casings.

Using the "12" wrench, unscrew the ten bolts securing the rear axle gearbox housing cover (one of the upper bolts secures the brake pipe bracket).

Carefully, so as not to damage the gasket, remove the rear axle housing cover.

Using a 12 key, unscrew the bolts of the two locking plates that fix the differential bearing adjusting nuts. Mark the caps of the adjusting nuts with a marker or chisel so that when assembling the rear axle gearbox of the Volga GAZ 31105 car, put each in its place.

Using the "17" head, unscrew the two bolts securing each cover of the adjusting nuts.

Remove both covers.

With a punch, we mark the adjusting nuts of the differential bearings so that they can be put in their original places when assembling the gearbox.

We take out the differential assembly from the rear axle housing of the Volga GAZ 31105 car. Remove the outer rings of the differential bearings. If the differential bearings are not supposed to be replaced, we mark their outer rings so that they can be installed in their original places when assembling the rear axle.

Using two probes, we check on both sides of each of the half-axle gears the axial backlash in the differential housing, which should be within 0.03-0.05 mm. Worn parts should be replaced. We mark the position of the driven gear on the differential housing.

Using the "15" head, unscrew the ten bolts securing the driven gear to the differential housing.

Use a soft metal drift to knock out the bolts from the holes. With light blows of a hammer through a drift made of soft metal, we knock the gear wheel off the differential case ...

And remove the rear axle driven gear from the differential housing.

Knock out the satellite axis stopper through a thin steel rod ...

And we take out the axle.

Turning (on the gears of the semi-axles), we install the satellites opposite the windows of the differential housing. We take out the washers of the satellites ...

And the satellites themselves.

Warning: Do not confuse washers of different semi-axle gears and satellites in order to assemble them in newly worn pairs if necessary.

We take out the gear wheel of one of the axle shafts ...

And remove the puck from it. Similarly, we take out the gear of the second axle shaft.

Using a puller, we press the inner ring of one of the differential bearings. In the absence of a puller, insert a chisel between the end face of the bearing inner ring and the differential housing. By striking the chisel, we move the inner ring of the bearing. Insert two screwdrivers or mounting blades into the resulting gap and press the inner ring of the differential bearing with a cage and rollers. Similarly, we press the inner ring with a cage and rollers of another bearing from the differential housing.

If the differential bearings are to be reused, wire the matching outer and inner rings with wire. By rotating the drive gear of the rear axle by the flange, you can approximately estimate the condition of its bearings. The shaft should rotate easily, without jamming, play or noise. We install an indicator (dial type) on a tripod with a graduation value of no more than 0.01 mm, resting its leg against the flange of the rear axle drive gear ...

And by moving the shaft by the flange, we measure the axial play of the drive gear. We write down the amount of backlash. If the axial play is more than 0.1 mm, make sure that the reason for this is not the pinion flange mounting nut, which is not tightened to the norm.

To eliminate the backlash, it is necessary to remove the adjusting washer installed on the gear shaft and measure its height with a micrometer. Remove the pinion flange.

We take out the drive gear of the rear axle of the Volga GAZ 31105 car with an adjusting washer from the rear axle housing (the gear can be knocked out with a hammer on the end of the shaft through a soft metal spacer).

Prying off with a screwdriver, take out the oil seal of the driving gear of the rear axle.

We take out the inner ring with a cage and rollers of the front bearing of the drive gear of the rear axle.

It consists of a beam, inside which all the main nodes are located.

It looks like the rear axle from GAZ 31105

In its central front part there is a crankcase, inside it there are two axle shafts and a gearbox with a driving differential. Repair of the gearbox and adjustment of the correct differential is carried out through a special hatch located at the rear of the crankcase. Attached to the side of the crankcase protective covers semi-axles, they transmit torque to the wheels. At the ends of the pipes there are welded flanges with grooves for the bearing and sockets for the brake shield connection bracket. The mechanism of this pattern is called the "banjo".

The axle of the driving gear of the bridge is 4.2 cm below the driven one, gear ratio the main gear is 4.556, this gear is called hypoid. The satellite box contains 2 axles, 4 satellites and 2 bevel gears. The body is made of two halves, bolted together.

Drawing of the device of the rear axle of the Volga 31105

Adjustment of the driven gear and pre-tensioning of the bearings is carried out by tightening or loosening the special nuts. The gear itself is bolted to the satellite box. The pinion gear is located next to camshaft on bearings.

The correct position is set by the adjusting ring located next to it and the bearing. The bearing is preloaded with a spacer ring.

The tips of the axle shafts are inserted into the spline holes of the gears. On the front side of which there are flanges connected to the hub by ten pins. The hub is located directly on the rear axle shaft housing. The wheel is hung and tightened on it.

Possible malfunctions

Problem - there is a metallic noise while driving

A metallic knock is heard from the brake drum

Oil change

In the gearbox of the GAZ-31105 car, it is advisable to change the oil every 30-40 thousand mileage. To do this, you will need an old container with a volume of at least one and a half liters, a flat screwdriver, a 12 hexagon and a 30 wrench.
Helpful advice! It is recommended to drive 5-10 km before replacing. The bridge oil should warm up to help it flow better.
It is more convenient to perform these actions on a lift or overpass:

Read also

The ZMZ 406 engine installed on the GAZ-31105 car

Helpful advice! In the absence of a large oil syringe, there is another filling method. You can use the hose into which the funnel is inserted. The oil is poured into the rear axle to the maximum, which is the edge of the filler hole.

• the plug is twisted into place, the resulting smudges are wiped with a rag;
• the breather is unscrewed from the protective housing of the left axle shaft with a 12 wrench;
• washed with diesel fuel, blown out by a compressor and screwed into place.

Filling oil in the gearbox Volga 31105

Helpful! When unscrewing the filler and drain plug, it is advisable to replace the copper gasket with a new one. This will give some guarantee that there will be no oil leaks from the rear axle in further operation.

Removing the rear axle

It is advisable to spend together. The weight of the rear axle of the GAZ-31105 is 86 kg, so the help of a partner will be required to carry out work on its removal. Procedure:

Advice! When disconnecting the tubing and hose, plug the hole on the first cap or bolt of the appropriate size. This will avoid leakage brake fluid from the system.

• the brake cables of the rear wheel drive are disconnected;
• bracket, step-ladders of springs are turned away and removed;
• having risen slightly above the springs, the rear axle is removed from the car;
• after the repair has been completed, the bridge is installed in its original place in the opposite order of the work performed, with the help of a partner.