KEY to figure ,-6:
Lock jam nut. 3/4-16
Washer, 3/4 std.
1. Round head screw
2. Top cover
3. Groove-pin 5/ 16 dia. x 9/16 inch
4. Cross shaft gear
5. Cross shaft R. H. outside mount
Hex head bolt. 5/ 8-11
6. Cross shaft L. H. outside mount
Locknut 5/ 8-11
7. Two speed gear, cross shaft
Landing gear cross brace
8. Groove pin, 3/8 in. dia. x I 1/ 2 in. Ig.
Landing gear brace
9. Shalt bushing
Right hand leg upper housing
10. Detent assembly
Left hand land gear assembly
11. Jack screw gear
Section III. TRAILER FRAME AND BED REPAIRS
c. King Pin Fifth Wheel Assembly. Weld new king
7- 16. General
pin to new fifth wheel plate per paragraph 7-17 b. and
The trailer frame and bed is specially designed and built
to support and transport the mobile substation. Due to its
construction the following items and assemblies are
considered repairable or replaceable; landing gear braces,
trap door assemblies, mud flap assembly, rear bumper
The location of the king pin is critical. Its
assembly king pin fifth wheel plate assembly,
position on trailer in relation to the front axle
undercarriage frame assembly and trailer deck.
of wheels affects towing quality .
a. Removal of Welded Members. The method used
d. King Pin Fifth Wheel Assembly Installation.
to separate welded members is dictated by the situation
Locate assembly on trailer as shown in figure 7-7. Clamp
and which member if not both, is being replaced. Care
in position and check position dimensions for location,
must be taken 80 as not to damage remaining members
reposition if necessary, or weld in place if correct.
to be reused.
b. Welding. Weld all joints per Mil-Spec.1261.
7-20. Under carriage Assembly Frame
c. Painting. Prime with metal primer per MILP858.
Paint with two coats of Semi-Gloss Olive Drab X24087
a. General. The undercarriage frame alignment is
(Federal Standard 595A) per MIL Std.-193.
important because it supports the suspension and wheel
assembly. The alignment affects the towing qualities of
7-18. Landing Gear Braces Repair
the trailer. Before straightening bent members all weld
a. Replacement. The braces are made from steel
joints should be inspected for cracks or tears. If joints are
tubing. Therefore, if bent it is best to replace them rather
damaged they should be cut. Bent parts should be
straightened or replaced. Use procedures outlined in
b. Installation. Install new brace with new hex head bolts
paragraph 717 a and 7-17 b
5/8-11 NC x 11/4 and 5/ 8-11 hex lock nuts at each end of
b. Suspension Mounts. When wheel suspension
7-19. King Pin Fifth Wheel Replacement
hangers are damaged they should be replaced. Use
a. General. To replace a damaged king pin a new
procedures in paragraph 7-17 a and 7-17 b for removal
fifth wheel plate is needed. The wheel plate must be
removed and a new king pin fifth wheel plate assembly
7-21. Trailer Deck Repair Replacement
b. Fifth Wheel Plate Removal. Cut weld securing
fifth wheel plate to trailer per paragraph 7-17 a.
The deck is made of two 1/4 inch thick steel plates. The
front plate is 10 feet long by 95 3/8 inches wide' the rear
plate is 20 feet long by 95 7/8 inches wide. If deck is
damaged to the point of repair, sections can be replaced.
By inspection of supporting members it can be
determined at what point a damaged area may be cut out