Front axle
The design of the front axle is shown on fig. 3-81. A number
"13" is painted on the reduction gear casing for distinction.
Fault diagnosis
Diagnosis
Remedy
Constant excessive noise at front axle operation
1. Worn or badly adjusted differ-
ential bearings
2. Wrong adjustment, damage or
wear of gears or bearings of
reduction gear
3. Low oil amount in axle case
4. Worn or destructed inner joint
bearing (axle shaft)
Noise at vehicle acceleration and engine braking
1. Incorrectly adjusted final drive
gear mesh at reduction gear
repair
2. Wrong side gap in final drive
gear mesh
3. Excessive gap in driving gear
bearing due to loose flange fas-
tening nut or worn bearings
Knock at the beginning of movement
1. Worn differential pinion shaft
opening in differential housing
Oil leak
1. Worn or damaged oil seal
2. Worn inner joint casing oil seal
3. Loose inner joint casing bear-
ing cover fastening or casing
covers, damaged sealings
Removal and refitting
Place the vehicle on the lift or over an inspection pit and raise
the vehicle front part.
Remove the anti-roll bar, the suspension crossmember tie-
rods and the crankcase protective cover. Disconnect the shock-
absorbers from the lower suspension control arms, and the input
propeller shaft from the front axle reduction driving gear flange.
Compress the suspension spring, disconnect the balljoint
from the lower arm and take off the spring, having smoothly
unloaded it. Disconnect the steering tie-rods from the steering
knuckle arms.
Remove the wheel cap and undo the wheel hub bearing nut.
Do the same on the other end of the suspension.
Loosen the muffler-to-front exhaust pipe clip, disconnect the
pipes and muffler brackets in the rear part of the vehicle and on
the gearbox.
Using key 02.7812.9500 undo the front exhaust pipe-to-
exhaust manifold fastening nuts and remove the pipe downward.
Undo the nuts that are fastening the engine front mounting
pads to the suspension crossmember brackets.
Support the front axle and undo the bolt fastening the right
bracket 22 (see fig. 3-81) to the engine and two fastening nuts of
the front axle from the left side.
Raise the engine by 25-30 mm, remove the front axle in
assembly with the front wheel drives.
Refitting of the front axle on the vehicle is carried out in a
reverse sequence. When refitting the axle, the fastening nuts and
bolts should be tightened with torque specified in the appendix.
Fill the front axle casing with transmission oil through the filler
neck, the oil level should reach the lower edge of the opening.
Dismantle
Place and fix the front axle on a bench for repair. Turn out
plug 5 and drain oil from the casing, then do the following from
both ends of the front axle:
- undo the inner joint casing bearing 7 cover 12 fastening nuts
and take out the joint, paying attention not to damage the sealing;
- after removing circlip 11 and spring washer 10, press off
bearing 7 from the inner joint casing 9 and remove oil seal 8.
Remove the axle casing stamped cover and sealing. It is not
recommended to remove bottom cover 2.
Dismantle the front axle reduction gear, using the procedure
described in subsection "Rear axle".
Inspection
Parts are inspected according to the procedure given in sub-
section "Rear axle", and besides ensure that:
- the ball bearing of the inner joint casing is not worn or dam-
aged (renew the bearing if the radial gap exceeds 0.05 mm);
- the inner joint casing is not deformed and the landing places
are not damaged;
- there are no scuffings and dents in the grooves of the inner
joint casing;
- there is no wear and cracks on the casing landing places.
Renew worn and damaged parts.
Reassembly
Before reassembly, match the ratio marks on the final drive
and the rear axle reduction gears.
Reassemble and adjust the front axle reduction gear, follow-
96
1. Renew worn components, adjust
differential bearings
2. Isolate problem in reduction gear,
repair or replace
3. Top up oil, check for oil leak from
front axle casing
4. Replace bearing
1. Adjust gear mesh as described in
subsec. "Rear axle"
2. Adjust clearance as described in
subsec. "Rear axle"
3. Adjust clearance (as described in
subsec. "Rear axle"), replace bear-
ing if necessary
1. Replace differential housing and
pinion shaft if necessary
1. Renew oil seal
2. Renew oil seal
3. Tighten nuts and bolts, replace
gaskets
Summary of Contents for Niva 4x4
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