Adjusting the distance between the end face of the drive gear and the axle of the differential
The driving and driven gears of the main gear are matched to each other in terms of noise and contact and are accordingly equally marked. In addition, the deviation of the actual distance between the end face of the drive gear and the axis of the differential from the nominal value in hundredths of a millimeter with a sign is marked on the drive gear «+» or «—».
Sign «+» indicates that the correction to the nominal value on the drive gear should be added to the actual distance between the end of the drive gear and the differential axle, and the sign «—» that it must be subtracted from the actual value of the distance.
Press the outer ring of the inner bearing with the adjusting ring removed during disassembly into the sockets of the rear axle housing «X» and the outer ring of the outer bearing of the drive gear.
Press on the press on the drive gear until it stops the rear new bearing.
Insert the drive gear into the axle housing and press on it a new front bearing using the mandrel 23 1 300 and the sleeve 23 2 150. The compression sleeve is not placed on the drive gear at this stage.
Press the flange without oil seal onto the drive gear using drift 23 1 300.
Tighten the drive gear flange mounting nut to a torque of at least 150 Н·м and measure the moment of resistance to rotation of the drive gear bearings, which should be within 180–300 N•cm.
Determine the indicator value «Y» (see picture), using for this a device with an indicator and a support ring, respectively: for axles with differential bearing caps fastened with four bolts - 33 1 381 and 33 1 382, and with six bolts - 33 1 191 and 33 1 192.
Reference values for axles with four-bolt differential bearing caps
Value «WITH» (distance between the end face of the drive gear and the axle of the differential): 11.02 mm.
Value «IN» (support ring thickness 33 1 382): 9.00 mm.
Reference values for axles with six-bolt differential bearing caps
Value «WITH» (distance between the end face of the drive gear and the axle of the differential): 9.02 mm.
Value «IN» (support ring thickness 33 1 192): 7.00 mm.
Determining the thickness of the drive gear adjusting ring
Determine the calculated value «C1» the distance between the end face of the drive gear and the axle of the differential according to the formula:
c1 = c + e+,
Where:
C - reference value of the distance between the end face of the drive gear and the axle of the differential, equal to 11.02 mm;
e+ - correction to the nominal value of the distance between the end of the drive gear and the axle of the differential, marked on the drive gear, equal to +0.07 mm.
C1 = 11.02 mm + 0.07 mm = 11.09 mm
Determine the actual value «C2» the distance between the end face of the drive gear and the axle of the differential according to the formula:
C2 \u003d B + Y,
Where:
B is the thickness of the support ring, equal to 9.00 mm;
Y is the value set using the indicator, which is, say, 2.06 mm.
C2 = 9.00 mm + 2.06 mm = 11.06 mm
Determine the value «A» according to the formula:
A \u003d C1 - C2,
Where:
A is the distance between the front end of the pinion inner bearing and the end of the axle housing socket for the adjusting ring.
A \u003d 11.09 mm - 11.06 mm \u003d 0.03 mm
Determine thickness «S» adjusting ring according to the formula:
S \u003d X - A,
Where:
X is the thickness of the adjusting ring installed in the crankcase housing of the bridge, equal, for example, to 3.76 mm.
S = 3.76 mm - 0.03 mm = 3.73 mm
In this case, install adjusting rings with a total thickness of 3.73 mm. If the calculated value «C1» greater than actual value «C2», then when determining the thickness «S» adjusting ring must be subtracted from the value «X» value «A» and vice versa.
Remove the drive gear from the crankcase of the bridge and press out the outer ring of the rear bearing of the drive gear from the crankcase socket.
Set the shims to the correct thickness, press in the rear bearing outer race, and insert the pinion gear with the new compression bushing into the axle housing.
Install a new drive gear seal.
Press the flange onto the end of the drive gear and tighten the flange fastening nut to a torque of at least 150 Nm. Measure the moment of resistance to rotation of the drive gear bearings, which should be 20 N•cm more than the value determined during disassembly. A greater excess indicates overtightening of the pinion flange mounting nut. In this case, it is necessary to remove the pinion gear, replace the shrink sleeve and re-tighten the flange fastening nut and check the moment of resistance to turning of the pinion bearings.
Lock the pinion flange mounting nut by bending the tabs of the lock washer.
Install the driven gear on the differential case in accordance with the mark applied during disassembly.
Tighten the bolts of the driven gear and the differential box, having previously applied a special adhesive such as Loctite to the threads. Each time the differential is disassembled, the driven gear mounting bolts must be replaced.
Check the condition of the O-rings on the differential bearing caps and replace them if necessary.
Insert the differential box into the rear axle housing.
Install the differential bearing cap without adjusting ring and tighten the mounting bolts.
Install the differential bearing cover, also without an adjusting ring, on the other side of the crankcase and gradually tighten the mounting bolts until the moment of resistance to turning the bearing, measured by a dynamometer, is in the range of 200-280 N cm.
Measure the gap between the differential bearing cap and the axle housing, thereby determining the total thickness of the adjusting rings installed under the bearing caps. Example. Assume that the gap between the differential bearing cover and the axle housing is 1.8 mm. To get the thickness of the adjusting ring installed under each bearing cover, you need to divide the indicated value by two, i.e. 1.8 mm: 2 = 0.9 mm.
Adjustment of the side clearance in the gearing of the final drive gears
Fix a fixture with an indicator on the axle housing and measure the backlash between the teeth of the drive and driven gears, which should be in the range of 0.08-0.13 mm.
If abnormal, achieve proper clearance by moving the differential bearing cap shims from one side of the axle housing to the other without changing the overall thickness of the shims.
Checking the contact of the working surface of the teeth of the final drive gears
For the final check of the quality of the engagement of the final drive gears, check the contact of the working surface of their teeth.
Lubricate the working surfaces of the driven gear teeth with a thin layer of lead oxide and check the contact of the working surface of the teeth of the drive and driven gears, while on the Gleason brand final drive, the tooth contact patch is checked on the driven gear teeth, and on the Klingeinberg brand final drive, on the drive gear teeth.