Section G. Maintenance Belarus– 510/512 Operating manual
105
To adjust the warm to sector mesh,
loosen the bolt 5, introduce a wrench to the
flange groove, turn the bushing clockwise
(to tractor motion direction) up to stop at
the middle position of the pitman arm 18,
then turn counterclockwise by 10 to 12 mm
as per the outer flange diameter. Tighten
up the bolt 5, start the engine and make
sure that the steering wheel rotates in the
both directions up to stop without jam-
ming.
If necessary, increase the clearance in
the mesh by turning the bushing counter-
clockwise to eliminate jamming.
To adjust the sector to rack mesh, re-
duce the thickness of the adjustment shim
pack 24 under the flange of the stop 24 to
obtain a clearance of 0.1 to 0.3 mm be-
tween the stop and the rack. When check-
ing the clearance, press the rack against
the sector.
The worm spherical nut 30 ensures
tightening of the thrust bearings 28. Cor-
rect tightening of thrust bearings is a cru-
cial condition of normal operation of the
steering booster. A too tightened nut can
cause a skewness of the distributor slide
valve and uneven force of turning. Before
tightening the nut, fasten the distributor
slide valve with two bolts, first putting
washers under the bolt heads up to the
thickness of the cover flange (Fig. 117).
Tighten the worm nut to a torque of 2
kgf•m (20 N•m), unscrew it by 1/12 to 1/10
turn to align the hole in the worm with the
cut for the nut splint and splint the nut.
Unscrew the two bolts fastening the distrib-
utor slide valve to the housing, install the
cover and secure the distributor slide valve.
To adjust the axial stroke of the pivot-
ing shaft 21, loosen the locknut 12, screw
in the adjustment bolt 10 up to stop
against the shaft end, then unscrew it by
1/8 to 1/10 turn and lock with the locknut.
To adjust the safety valve, connect a
pressure gauge with a scale to 100 kgf/cm²
(10 MPa) min. to the discharge manifold or
to the valve cover instead of the plug 1.
Turn the steering wheel to stop, engage the
engine maximum speed and rotate the ad-
justment screw 3 of the relief valve until the
pressure gauge reading is 88 kgf/cm² (8.8
MPa). After adjusting the valve, lock the
cap with wire. Make adjustment at an oil
temperature of 50±5°C.
Check the steering wheel free travel
with the engine running while the tractor
is stopped. The free travel must be 20°C
max. in such a case. In case of a too long
free travel check plays in the steering
drive joints, tighten up the nuts fastening
the pitman arm, sector and pivot rods, ad-
just the steering rod joints, check tighten-
ing of the worm, worm to sector mesh,
sector to rack mesh and axial stroke of
the steering booster pivoting shaft.
