61
Tighten the U
-
bolt nuts in accordance with Fig. 48:
- front springs: first with a torque of 200-250 N m (20-25 kgf m) and finally to
400-500 N m (40-50 kgf m);
- rear springs: first with a torque of 250-300 N m (25-30 kgf m) and finally to
580-660 N m (58-66 kgf m).
When reassembling lubricate the U
-
bolts’ threading with graphite grease or
ТСгип
-
type grease
Tighten the nuts of U-bolt 21 (see Fig. 45) fixing the front spring plate eye on a
loaded truck in the following sequence of operations:
- screw the nut home;
- back off the nut by 1.5-2 turns;
- punch the threading in two opposite points on each stem.
Complete tightening of the front spring U-bolt nut is not allowable, because it
would hinder movement of the leaves and cause quick damage of the U-bolt and
eye fasteners during operation. If there is no clearance (less than 0.2 mm) between
the eye and upper leaf, repair or replace the eye.
Should the spring be dismantled from the truck, torque the nuts of U
-
bolt 21
to 20-28 N m (2.0-2.8 kgf m) and punch in two opposite points. See that the bolt 24
fastening the plate eye is properly tightened. Torque the nuts to 280 N m (28 kgf m).
If the cotter pin hole in the bolt and the nut slots fail to match, tighten up the nut
and cotter it.
If the brace is slackened on the front spring rear brackets, tighten up the brace
bolts. For upper bolt 14 apply a torque of about 120-160 N m (12-16 kgf m), and
for the lower bolt nut, 180-220 N m (18-22 kgf m). Lock the bolts by bending the
retaining strip on the heads.
Should the first leaf ends of the rear spring be worn by half of their thickness
interchange the first and second leaves. It is not recommended to interchange the
leaves on the trucks having a load of 12 000 kg on the rear bogie.
To dismantle U-bolts 2 (see Fig. 47) without decoupling the torque rods jack
the truck up, place a stand under the walking-beam axle or under the truck frame.
Unscrew the U-bolt nuts and take off the spring pad. Lower the truck onto the stand
in such a way that a gap is available between the spring and walking beam. Turn the
walking beam by a small angle and remove the U-bolt.
To eliminate axial displacement of the walking beam unload the walking beam by
hanging the truck frame in such a way that the spring ends are not jammed in the
supporting brackets. Remove cap 27 of the walking-beam. Slacken coupling bolt 18,
unscrew nut 26, wipe dry the thread of the walking-beam nut and axle and lubricate
with
УГ
-6
sealant
(alternatively with Loktite-243 or Loktite-573). Screw home nut
Fig. 48. Tightening Diagram of Spring
U-bolt Nuts:
1-spring; 2-rear spring pad (front axle beam
clamp); I-IV - U-bolt nuts tightening order
