TM 9-2320-361-34
15-39. HORIZONTAL LEVELING WORM GEAR MAINTENANCE (Contd)
b. Disassembly
1.
2.
3.
4.
5.
6.
7.
Remove safety wire (8), loosen setscrew (9), and remove sprocket (10) and woodruff key (11) from
worm gear shaft (6). Discard safety wire (8) and woodruff
key (11).
Remove lubrication fitting (17) and bushing (16) from shaft (6).
Remove setscrews (1) and (4), two screws (2), and lockwashers (3) from worm gear housing (5),
Discard lockwashers (3).
NOTE
Measure and record distance shaft extends from worm gear housing.
Loosen worm adjusting bearing (15).
Aline woodruff
key (12)
in
shaft
(6) with keyway of thrust washer (13). Tap round end of shaft (6)
and remove sleeve bearing (7), woodruff key (12), and shaft (6) from worm gear housing (5).
Remove thrust washer (13), worm gear (14), and adjusting bearing (15) from worm gear housing (5).
Remove woodruff key (12) and sleeve bearing (7) from shaft (6). Discard woodruff key (12).
c. Inspection
1. Check worm gear housing (5) for cracks or other damage. Repair by welding if cracked (TM 9-237).
Replace if damaged.
2. Check all parts for small chips, burrs, and scratches. Raised metal can be removed with a fine mill file.
3. Check sprocket (10) and worm gear (14) for chipped and broken teeth. Replace if damaged.
4. Inspect adjusting bearing (15), shaft (6), sleeve bearing (7), and thrust washer (13) for wear or other
damage. Refer to table 15-5, Horizontal Leveling Worm Gear Wear Limits, for measurements.
Replace if worn or otherwise damaged.
Table
15-5. Horizontal Leveling
Worm Gear Wear Limits.
ITE M
NO .
WEAR LIMITS/TOLERANCES
ITEM/POINT OF MEASUREMENT
INCHES
6
7
13
15
Shaft (diameter)
Sleeve bearing
Inside diameter
Outside diameter
Thrust washer (thickness)
Bearing (inside diameter)
1.371-1.372
1.376-1.378
1.99-2.00
0.41
1.37-1.38
d. Assembly
1. Install adjusting bearing (15) and worm gear (14) in worm gear housing (5).
MILLIMETERS
34.82-34.85
34.95-35.00
50.55-50.80
10.41
34.80-35.05
2.
Install thrust washer (13) so that setscrew notch faces away from worm gear (14) and keyway alines
with keyway of worm gear (14).
3. Install new woodruff
key (12) in shaft (6) and install shaft (6) in worm gear housing (5).
15-148