Unscrew the oil drain plug and drain the oil from the final drive housing
Remove the four bolts securing the rear propeller shaft to the rear axle drive gear flange and move the rear propeller shaft to the side.
Remove both axle shafts.
Remove the ten mounting bolts and remove the gearbox cover.
Remove cotter pin 1, unscrew fastening nut 2 and remove flange 3 from drive gear splines.
Remove the screws 1 and remove the locking plates 2 of the adjusting nuts.
Mark bearing caps 3, unscrew two fastening bolts 4 on each side and remove bearing caps.
Loosen the two adjusting nuts 1 located on each side of the differential.
Remove differential 3 with bearings and driven gear assembly and mark the outer and inner races of bearings 2 so as not to confuse them during installation.
Remove drive gear 1. This leaves the front bearing of the drive gear shaft in the rear axle housing.
Remove the drive gear flange seal.
Remove the front bearing from the rear axle housing.
Press the outer races of the outer and inner bearings of the drive gear shaft out of the crankcase.
Disassembly of the final drive gear shaft
Compress the front bearing inner race.
Remove the front bearing spacer 1.
Compress the rear bearing 2 with the inner race and remove the shim.
Differential disassembly
Mark the relative position of the driven gear 1 and flange 2 of the differential box.
Remove the nuts of the 3 bolts securing the driven gear to the differential box and knock out the bolts from the driven gear sockets without damaging the threads.
Remove (compress) the driven gear from the differential case.
Using a thin hard rod, knock out the pinion axle stopper from the hole 2 of the differential box.
Knock pinion axle 1 out of the box.
Remove the satellites 1 with washers by rolling, and then remove the side gears 2 with washers from the sockets. Press differential bearings 3.
It is recommended to wire the bearings to their respective outer rings.
Inspection and troubleshooting of main gear parts
Rinse and dry the final drive parts.
Check differential box. If cracks are found on the box, it must be replaced.
Check the final drive teeth. If they have chipping, chips or scuffs, both final drive gears must be replaced.
Inspect side gears, pinions, axle and washers.
On side gears, pinion gears, there should be no broken teeth and traces of increased wear of the spherical surface.
Surface the axis should be smooth and even and should not have steps at the landing sites of the satellites.
If the washers are unevenly worn, they must be replaced.
Internal mating surfaces of the differential box must not show signs of wear.
Check the surfaces of the bearing seats for signs of wear. Replace worn parts.
The pinion and differential case bearings must be free of pitting, pitting, and visible wear on the rolling surfaces.
Differential assembly
Press the final drive gear onto the differential box, matching the previously made marks.
Insert ten bolts into the holes of the driven gear and tighten the fastening nuts with a torque of 68–75 Nm (6.8–7.5 kgf m).
Press the roller bearings onto the seats of the differential box.
Insert side gears with washers into differential case.
Insert satellites with washers into the windows of the differential box, engaging them with side gears.
Then turn the satellites so that the axle holes on the differential box and the satellites line up.
Insert the axis of the satellites, aligning the holes in the box and the axis for the stopper.
Measure the axial clearance of the side gears using two feeler gauges.
With correctly selected washers, the gap should be between 0.03–0.05 mm.
Insert the axle stop and punch out the hole.
Adjustment of the main gear GAZ-3110 according to the tooth contact patch
If at least one of the parts of the rear axle that affects the size of the mounting dimension has been replaced, then it is necessary to select the adjusting ring of the drive gear shaft.
Press the outer races of the pinion shaft bearings into the rear axle housing.
Install the rear bearing on the drive gear shaft, insert the drive gear into the rear axle housing and install the front bearing.
Install the pinion flange. Tighten the nut, turning the shaft by the flange so that the rolling elements of the bearings fall into place.
The nut is tightened so that the turning torque of the new bearings is 1.75–2.25 Nm (0.175–0.225 kgf m).
Measure distance A from the end of the drive gear to the rear end of the rear axle housing.
Install mandrel 1 with a length of 190 mm and a diameter of 90 -0.01 "lower limit" in the seats of the differential bearings.
Install the differential bearing caps and tighten the mounting bolts to 90–100 Nm (9.0–10.0 kgf m).
Measure distance B from the mandrel to the rear end of the rear axle housing.
Calculate the size M from the end of the drive gear to the axis of the differential using the formula M \u003d A - B - D / 2, where
- A - distance A from the end of the drive gear to the rear end of the rear axle housing, mm;
- B is the distance from the mandrel to the rear end of the rear axle housing, mm;
- D is the diameter of the mandrel, equal to 90 mm.
Calculate the thickness T of the adjusting ring as the difference between the actual dimension M and the mounting dimension of 65 mm.
It is necessary to take into account the value of the correction P of the mounting dimension indicated on the end face of the drive gear, with the corresponding sign:
T = M - 65 - P, where
- M is the size from the end of the drive gear to the axis of the differential, mm;
- Р is the value of the mounting dimension correction, mm.
It should be noted that the value of the correction P can be with the sign "+" or "-" and must be substituted into the formula with its own sign, i.e. with a correction value with a “+” sign, it is subtracted, and with a “–” sign, it is added.
Select an adjusting ring from a repair kit with a calculated thickness (T ± 0.02) mm from the 22 groups supplied as spare parts. The group number is indicated on the adjusting ring.
Remove the mandrel.
Remove the drive gear from the rear axle housing by unscrewing the fastening nut and removing the drive gear flange.
Press the rear bearing off the pinion shaft, install the selected adjusting ring and press the rear bearing again.
Install the drive gear into the rear axle housing.
Select the front bearing preload spacer ring. The spacer ring is installed between the shoulder of the shaft and the inner ring of the front bearing.
For spare parts, 47 groups of spacer rings are supplied with a thickness of 4.05 to 5.43 mm every 0.03 mm.
Pick up location ring so that the torque of the drive gear shaft bearings is 1.5–2.5 Nm (0.15–0.25 kgf m) with the flange installed and the nut tightened to a torque of 160–200 Nm (16–20 kgf m).
When tightening the nut, it is necessary to turn the shaft by the flange so that the rolling elements of the bearings fall into place.
After selecting the spacer ring, finally install the front bearing in place.
Lubricate the lip of the drive gear flange oil seal and press it flush with the end of the crankcase.
Install the drive gear flange and tighten its fastening nut to a torque of 160–200 Nm (16–20 kgf m).
Install the cotter pin and check the bearing torque again.
Install the differential with bearings in the rear axle housing and insert the adjusting nuts into the threads until they touch the bearings.
Install the bearing caps in accordance with the markings and tighten the bolts of their fastening so that the adjusting nuts rotate freely.
Install the indicator stand. In this case, the indicator leg should touch the tooth surface near the outer end of the driven gear and be directed along the radius to the tooth surface.
Determine the amount of the resulting lateral clearance, for which purpose select the clearance between the gears of the main gear by turning at a certain angle to one of the sides of rotation of the driven gear until it stops and set the indicator scale to zero.
Measure the side clearance with the indicator, swinging the driven gear all the way around the axis in both directions.
Measurements should be made at least at eight equally spaced points of the gear.
At each measurement, it is recommended to block the drive gear from turning. The side clearance should be between 0.15–0.25 mm.
If the side clearance does not fall within these limits, it is necessary to move the gear in the required direction with the adjusting nuts.
Adjust differential bearings. To do this, install the indicator and use the adjusting nuts to set the axial clearance in the bearings to about 0.05 mm.
Then, provide the necessary bearing preload with the help of adjusting nuts by the amount of actually measured axial play, adding to this value 0.1 mm for bearings with a mileage of less than 10 thousand km and 0.05 mm for bearings with a mileage of more than 10 thousand km .
In this case, the rotation of one adjusting nut relative to the other by one groove corresponds to a movement along the axis by 0.03 mm.
Check again and adjust side clearance if necessary.
To reduce the gap, the nut on the side of the driven gear must be tightened and at the same time loosen the opposite nut by the same number of grooves, to increase the gap, the actions are directly opposite.
Always loosen the nuts one slot more than required and then tighten one slot more.
Finally tighten the differential bearing cap bolts to 90–100 Nm (9–11 kgf m).
Check the side clearance again and adjust if necessary.
You can also adjust the meshing of the final drive gears by the contact patch of the gear teeth.
This method is more laborious, but at the same time, it can be used to get the best result of the gear engagement of the final drive.
Install the locking plates of the adjusting nuts and tighten the bolts from the mount.
Calculate the thickness of the adjusting ring 1 and install the drive gear with the matched ring in the crankcase.
In this case, the spacer ring 26 is selected only after the final installation of the final drive gears.
Install the driven gear differential and adjust the differential bearings.
Apply a thin layer of long-drying thick primer to all teeth of the drive gear.
Turn the drive gear one turn in both directions.
Carefully inspect all the teeth of the drive gear on both sides. At the points of contact of the gears, the soilovka will be erased.
Carefully inspect all the teeth of the drive gear on both sides. The primer will be erased at the contact points of the gears.
If the gear mesh is properly adjusted, the contact patch should be located in the center of the tooth of the drive gear.
If the contact patch is located on the upper edge of the tooth, it is necessary to move the drive gear towards the driven gear. To do this, you need to select and install an adjusting ring 28 of greater thickness.
If the contact patch is located at the base of the tooth, then the drive gear must be moved away from the driven gear. To do this, you need to select and install an adjusting washer 1 of a smaller thickness.
If the contact patch is located at the front end of the tooth, then the driven gear must be moved away from the drive gear.
To do this, the adjusting nut 5 on the side of the driven gear must be unscrewed by the required number of grooves and at the same time tighten the opposite nut by the same number of grooves.
In this case, it is always necessary to unscrew the nut one groove more than required, and then tighten it one groove.
If the contact patch is located at the rear end of the tooth, then the driven gear must be moved to the drive gear.
To do this, adjusting nut 5 on the side of the driven gear must be tightened to the required number of grooves and at the same time, unscrew the opposite nut by the same number of grooves.
In this case, it is always necessary to unscrew the nut one groove more than required, and then tighten it one groove.
Due to inaccuracies in the manufacture of gears, the contact patch on different teeth may “walk”.
Therefore, it is necessary to set the gears so that the location of the contact patch on all teeth approaches the correct position.
Repeat step 30 until the desired result is obtained. At the same time, at each check, it is necessary to restore the soil layer on the teeth.
After adjusting, finally assemble the rear axle.
Pour 1.65 liters of transmission oil through the filler hole into the final drive housing.
