Transfer Box Inspection; Drive Line Fault Diagnosis; Reducing The Rear Axle Shaft Flange Nut - Lada Niva 4x4 Service Manual

Fig. 3-46. Reducing the rear axle shaft flange nut:
1 - tool 67.7820.9520; 2 - flange retainer
After reassembly, top-up oil in the transfer box to the lower
edge of the filler neck.
Inspection
Prior to inspection, all parts of the transfer box should be
carefully cleaned with a brush and a scraper, and then washed.
Blow the parts with a jet of compressed air. Especially carefully
wash and blow the bearings, but do not let them to rotate quickly
under the air jet to prevent damage.
Casing and covers. There should be no cracks on the cas-
ings and covers, no signs of wear or damage (dents, chipping) is
allowed on the surface of bearing housings. Damage on surfaces
between casing and covers may result in misalignment of shafts
and oil leak. Small damages can be repaired with a file. Renew
the parts with significant damage or wear.
Seals. Carefully inspect their condition. Renew in case of
even insignificant damages. The wear width of working edges
should not exceed 1 mm.
Shafts. On working surfaces, threaded parts and on shaft
splines no damages are allowed. To check the runout of the input
shaft and the drive shafts of the front and rear axles place them
on V-blocks and turn manually. The runout of face ends of bear-
ing thrust shoulders should be no more than 0.01 mm.
When checking the layshaft, pay attention to the condition of
the gear unit and the speedometer drive gear. No chipping or
excessive wear of teeth is allowed. Renew bad parts.
Gears. When inspecting the gears, check the condition of
teeth and landing surfaces. No teeth chipping or excessive wear
is allowed. There should be no scuffings or wear on gears land-
ing surfaces that may cause large gaps.
Check the gear mesh clearance; the mounting gap should be
0.10 mm, maximum allowed - 0.20 mm.
The mounting gap between the low gear and bush, and
80
between the input shaft and top gear should be 0.05-0.10 mm,
maximum allowed - 0.15 mm. If wear exceeds the limits, renew
the gears.
Bearings. Ball and roller bearings should have no damages
on races, cages, rollers or balls, and no cracks and choppings on
rings. The bearing radial gap should not exceed 0.05 mm.
When turned, a clean dry bearing should not knock. It should
run smooth, without jamming. Renew damaged bearings.
Rods, forks. No deformation of forks and jamming of rods in
the casing apertures is allowed. In case of jamming, renew the
detent components. Weak springs should be replaced. The
spring length under load of 99.15-114.85 N (10.2-11.8 kgf) should
be 19 mm, when let free - 23.3 mm.
Ensure there are no traces of jamming on the gear shift clutch
hub and especially on the clutch sliding surfaces, and also on the
differential housing splines. Scuffings and burrs can be smoothed
with a file. Special attention should be payed to the clutch teeth
end faces; if their damage interferes with the clutch sliding when
shifting the gears, renew the clutch.
Differential. Check the differential pinion shaft surface and
the apertures in the differential housing; in case of insignificant
damages smooth the surfaces with fine sandpaper, and at major
damages - renew.
Check the surfaces of axle drive gear journals and their
mounting apertures in differential housings, and also the adjust-
ing washer surfaces and mating end face surfaces on the axle
drive gears and housings. The detected damages can be
removed by fine sandpaper or velvet file; renew the parts in case
of major damages or wear.
With spring washer 15 being removed (see fig. 3-42) ensure
there is no radial movement of circlip 8 in shaft grooves 14.
Replace circlips in case of free play.
Drive line
Design of propeller shafts is shown on fig. 3-47, 3-48, 3-49.
Fault diagnosis
Diagnosis
Knock in shafts at pull away,
at hard acceleration or gear switching
1. Loose fastening bolts and nuts
on flexible coupling and U-joint
flanges
2. Excessive backlash in spline
joints of front or rear propeller
shafts
3. Worn U-joints
Remedy
1. Tighten nuts to torque specified
in Appendix
2. Check gap on spline middle
diameter; if it is more than 0.30 mm
- renew worn parts
3. Repair joints and renew worn
parts