Adjustments Of Hydraulic Power Steering - Belarus 80.1 Operation Manual

3.13.2 Adjustments of hydraulic power steering

In hydraulic booster meshing "worm-sector", meshing "sector-rack", worm nut tight-
ening, sector nut tightening, axial stroke of the turning shaft, safety valve are adjusted.
To adjust meshing "worm-sector" loosen bolt 19 (figure 3.13.1), get wrench into the
flange slot of bushing 20, turn bushing 20 clockwise (along tractor travel) against the stop
with drop arm 1 in neutral position (gauge stick 2 (figure 3.13.2) is sunk to the full in the
body of the differential lock sensor) then turn bushing 20 (3.13.1) anticlockwise 10 -12 mm
along the outer diameter of the flange. Tighten bolt 19, start the engine and make sure that
the steering wheel is not jammed when turned in both directions as far as it will go. If nec-
essary increase backlash in meshing, turning bushing 20 anticlockwise until jamming is
ruled out.
To adjust meshing "sector-rack" reduce the sickness of adjusting shims set 7 under
stop flange 6 until backlash 0,1 – 0,3 mm between stop and rack is reached. When check-
ing backlash press up rack against the sector.
By means of worm spherical nut 13 tightening of thrust bearings 11 is ensured.
Proper tightening of the thrust bearings is the essential condition of normal operation of the
hydraulic booster. Excessive tightening of the nut can cause slant of the spool and irregu-
lar force of turning. Before tightening nut 1 (figure 3.13.3) fasten the distributor valve by
two bolts 5, having first placed washers 4 under the heads of bolts 5 as thick as flange of
the cover. Tighten nut of worm 1 with a torque from 19 to 21 N•m, unscrew it 1/12 – 1/10
turns until the hole in the worm aligns with the slot for lock pin of the nut and forelock it.
Screw out bolts 5 of the distributor valve mounting to the housing, install the cover and fas-
ten the distributor valve with four bolts 5. When the spherical nut of the worm is properly
tightened there is no play between the spool and bearing cages, and there is a kickback of
the steering wheel (return of the spool to neutral position) after rotation to the left has
stopped.
1 – spherical nut; 2 – washer; 3 – sliding sleeve; 4 – mounting washers; 5 – bolts.
To adjust axial stroke of turning shaft 4 (figure 3.13.1) loosen locknut 26, screw ad-
justing bolt 24 all the way into the end of the shaft, then unscrew it 1/8 – 1/10 of a turn and
lock with locknut 26.
Figure 3.13.3 – Tightening of the worm spherical nut
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80-0000010B OM