4-61. COUNTERBALANCE MAINTENANCE (M447, M447C, AND M750).
This Task Covers:
Cleaning and Inspection
l Semitrailer parked on firm, level ground.
l Dry cleaning solvent (Item 14, Appendix E)
l Three cotter pins
l General mechanics tool kit
l Four rivets
l Hydraulic jacks
Set jacks or blocking under lower folding side door to release tension on wire rope assembly (7).
Remove cotter pin (11) and headed straight pin (6) from wire rope assembly (7) and upper end of
counterbalance bar (25). Discard cotter pin.
Remove two cotter pins (9), headed straight pins (5 and 22), washers (8), and upper and lower groove pulleys
(10) from corner post (12).
Unscrew turnbuckle (14) from lower end of wire rope assembly (7).
Remove upper end of wire rope assembly (7) from corner post (12).
Remove four screws (4), two brackets (3 and 19), connecting link (2), arm assembly (16), and link (18) from
upper and lower folding side doors.
Remove two screws (24), guide clip assemblies (23), and counterbalance bar (25) from corner post (12).
Remove rivet (1) and bracket (3) from connecting link (2). Discard rivet.
Remove rivet (26) and connecting link (2) from counterbalance bar (25). Discard rivet.
Remove headless straight pin (20), lower end of wire rope assembly (7), and bracket(19) from link (18).
Remove two rivets (21) and washers (17) from link (18) and arm assembly (16). Discard rivets.
CLEANING AND INSPECTION I
Dry cleaning solvent, P-D-680, is toxic and flammable. Always wear protective goggles
and gloves, and use only in a well-ventilated area. Avoid contact with skin, eyes, and
clothes, and DO NOT breathe vapors. DO NOT use near open flame or excessive heat.
The solvents flash point is 1000F-138°F (38°C-590C). If you become dizzy while
using cleaning solvent, immediately get fresh air and medical help. if solvent contacts
eyes, immediately wash your eyes and get medical aid.
Clean all parts with dry cleaning solvent and dry thoroughly.
Inspect wire rope assembly for wear, breaks, kinks, or frayed areas.