CHAPTER 4
REPAIR OF CRANE-SHOVEL UPPER WORKS AND LOWER WORKS
Section I. UPPER WORKS
shaft. If disassembly is desired:
4-1.
General.
(a) Remove lockwire (6) and two
The upper works consists of the revolving frame, main
capscrews (5) and retainer plate (7) from left end of shaft.
machinery, engine, operating controls, and the operator's
(b) Remove sprocket (25).
cab. This section contains instructions for repair and
(c) Remove bearing. Bearing is a "tap-
replacement of major components on the upper works.
fit" and it may be necessary to tap it lightly (through a wood
4-2.
Transmission
block) to free it from shaft.
a. General The transmission is a fully enclosed
c. Inspection and Repair.
Clean all parts
multiple-strand chain drive running in oil. The shaft has a 2'
thoroughly and inspect for damage and excessive wear.
inch diameter, is alloy steel, and splined at both ends to
For gear and bearing inspection and repair procedures, see
accept driven sprocket and pinion. It is mounted on anti-
paragraph 2-8. Replace damaged gasket or hardware.
d. Reassembly and Installation
b. Removal and Disassembly.
(1) Mount left bearing from left end of shaft
(1) Drain oil out of both transmission chain
tapping lightly into place with soft babbitt hammer or through
case and gear case. Remove chain case cover
a wooden block. Shield on bearing must face sprocket.
(20, fig. 4-1). Remove gasket seal (74) of revolving frame
(2) Put key in place and press sprocket on
at left of chain case (36). Remove chain case.
shaft. This requires a press of 20-to 30-tons capacity.
(2) Remove transmission chain (24) by
(3) Install gear and retainer plate on end of
splitting at connecting link.
shaft, fasten securely with two capscrews and lock with
(3) Remove sump pan (58) from gear case
wire.
(75).
(4) Insert shaft in revolving frame and push it
(4) Remove hoist clutch yoke fulcrum pin (53)
through until the right end enters the gear enclosure.
from right bearing cover on right side of gear case.
Note. Check oil seal in gear case. Replace if
(5) Remove right bearing cover.
necessary.
(a) Take out four capscrews and their
(5) Put the hoist pinion in place and push
lock plates.
shaft through it.
(b) Remove cover and gasket.
(6) Push pinion back against shoulder and
(c) If gasket is loose, put it away where it
start right bearing on end of shaft.
will not be damaged.
(7) Insert wood block between bearing and
(6) Remove right retainer plate by removing
side of gear case. Drive shaft into bearing until it seats
lockwire (28) and two capscrews (27). Leave the left
against shoulder of shaft.
retainer plate on for pulling shaft.
(8) Remove block and insert bearing on end
(7) Place a block of wood inside the gear
of shaft in housing inside of gear case.
case at the left of the hoist pinion so shaft can be pulled and
(9) Install right bearing retainer, insert two
force off the "tap-fit" right bearing with the pinion. Block of
capscrews and lock with wire.
wood should be well located to distribute the load against
(10) Install right bearing cover with gasket, and
the inside of the gear case and prevent springing the case.
fasten in place with four capscrews and lock plates.
(8) Pull shaft using sprocket spokes to assist
(11) Install hoist clutch yoke and insert and
in applying traction. Shaft should come free with relative
lock clutch yoke fulcrum pin.
ease but it may be necessary to tap it lightly to work it free
(12) Wash out and replace oil sump pan on
from the right bearing. After it clears the bearing it should
gear case.
come out freely. Catch hoist pinion under gear case before
(13) Replace transmission chain by inserting
it drops free. Remove the right bearing from its seat in the
pins and plates and locking with cotter pins.
side of the case.
(14) Install chain case. Install gasket seal of
(9) Sprocket and left bearing are still on the
4-1
