Lada Niva 4x4, Руководство по обслуживанию

Страница: 19 / 81

Spontaneous gear or differential lock disengagement
1. Worn teeth on gears and cou-
plings
2. Weak detent spring or detent
component wear
3. Incomplete gear engagement
and differential lock due to drive
system component damage or
due to dents on gears, clutches
or splines
Oil leak
1. Damaged sealings
2. Loose nuts and pins fixing cov-
ers to casing
3. Worn or damaged shaft seals
4. Worn transfer drive rod seals
Transfer box / car body floor vibration
trouble-shooting
(in the area of front seats)
First of all note, at what speed does the transfer box vibration
occur, then start with the diagnosis.
Test 1. Place the transfer- and gearbox levers in neutral posi-
tion and start the engine. Set engine speed equal to vehicle
speed at which vibration occurs.
If vibration still exists on a parked vehicle, it is necessary to
check engine mounting and supports, as they are the reason of
vibration.
Test 2. If during test 1 vibration was not diagnosed, place the
transfer levers in neutral position, start the engine, engage direct
gear and set engine speed equal to vehicle speed at which vibra-
tion occurs.
If vibration is observed on a parked vehicle at this engine
speed, the reason should be looked for in the layshaft (out-of-bal-
ance, bended fastening bolts or flexible coupling flange, jammed
CV-joint).
Test 3. If no vibrations was diagnosed during tests 1 and 2,
go to test 3. Accelerate the vehicle to the speed, at which vibra-
tion occurs, and place the transfer- and gearbox levers in neutral
position. If vibration persists, the reason should be looked for in
the front or rear propeller shaft (out-of-balance, jammed joints) or
interaxial differential is not balanced.
Transfer box - removal, refitting and centering
Removal.
Place the vehicle over an inspection pit or on a lift.
Release the handbrake and place the gear- and transfer-box
levers in neutral position. Undo the fastening screws of the gear
lever surround and remove it. Remove the handles and gaiters
from the levers. Undo the fastening screws and remove the cover
cap and the bellows.
Disconnect the speedometer cable from the transfer box and
the wires from the differential lock warning lamp sensor. Turn the
driveshafts and disconnect the driveshaft flanges from the trans-
fer box shafts, and the layshaft flange from the gearbox output
shaft flange.
Unscrew nuts 3 (fig. 3-37) on the transfer box mounting
bracket 1 fastening bolts and remove it together with brackets
and shims 5, which are placed under the brackets, in assembly
with the layshaft. Mark each shim so that to refit them in the same
amount.
Refitting and centering the transfer box is done in the fol-
lowing order:
- ensure proper refitting of engine support pads in brackets
(the centering washers of the engine front support pads should fit
into the appropriate apertures in the side brackets) and perfect fit
of transfer box supports to the car body bottom. If necessary,
straighten the floor surface under the supports;
- place the transfer box on the vehicle, but do not tighten com-
pletely mounting bracket nuts 4 and 5 (fig. 3-38);
- by moving the transfer box in different directions, find such
location, at which the flanges of the transfer box input shaft and
the layshaft will be on one level, parallel and with minimum clear-
ances between them; the transfer box shafts should be parallel
with the car bottom;
- refit the earlier removed shims under the mounting brackets,
fully tighten the fastening nuts;
- reconnect the front and rear propeller shafts to the transfer
box shafts; attach the speedometer cable, and the wires to the
differential lock warning lamp sensor.
When replacing the transfer box, and also at engine rear
mount "settle down", resulting in vibration of the transfer box,
renew and match shims 5 (see fig. 3-37) with those of proper
thickness.
Matching the shim thickness:
- ensure proper refitting of engine support pads (see subsec-
tion. "Engine removal and refitting");
- separate the flanges of the transfer box input shaft and the
layshaft;
- slacken the nuts that are fixing the transfer box supports to
the car body, remove the shims and, and by moving the transfer
box in different directions, find such location, at which the sepa-
rated flanges will be on one level, parallel and with minimum
clearances between them; the transfer box shafts should be par-
allel with the car body bottom;
- the formed gap between the floor and the support should be
filled with a sufficient amount of shims;
- align the flange centering collars without tensioning the supports of the transfer box
and the engine, and while keeping the transfer box in this place, tighten the earlier slackened
support nuts;
74
1. Renew worn parts
2. Renew springs or worn parts
3. Straighten deformed parts or
renew, clean burrs and scores,
replace bad parts
1. Renew gaskets
2. Tighten nuts and pins in places of
leak
3. Renew oil seals
4. Renew sealing ring