Landoll 825B Series, Operator'S Manual

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4-7.2 Axle Alignment
Proper axle to king pin alignment is necessary
to obtain straight tracking. If axle alignment is off,
“dog-tracking” occurs. Check alignment manually
or by using a semitrailer alignment machine. In ei-
ther case, a thorough inspection of the complete
suspension must be performed and all defects cor-
rected before aligning.
a. Manual Alignment Procedure
1. Position semitrailer on a firm and level
surface. Insure that the undercarriage is in
the rear most position. Eliminate any
suspension binding due to sharp turns or
unusual maneuvers.
2. Detach tractor from the semitrailer and jack
the
trailer up sufficiently to permit
measuring from the underside of the trailer.
3. Suspend a plumb bob at axle height from
the center of the king pin.
4. Measure (D) from the plumb bob to the
center point on one end of the axle. Record
this measurement
(See Figure 4-9) .
5. Measure (D1) to the other end of the axle in
the same manner as in
Step 4. . Record this
measurement (See Figure 4-9).
6. Set D about 1/8" shorter than D1 to insure
proper trailer tracking on slope of road.
7. The suspensions must be in good repair
with no binding or other restrictions before
a l i g n i n g . A l l d e f e c t i v e p a r t s o f t h e
suspension or axles must be replaced
immediately.
b. Air Ride Suspension Axles
The air ride suspension is aligned and ad-
justed at the factory and it should not be necessary
to align the axles. If, however it does become nec-
essary to align the axles, the procedure is as fol-
lows:
1. To align air ride suspension axles, locate
the front axle equalizer beam pivot bolt in
front hanger at front end of lock nut.
Loosen the suspension pivot bolt lock nut.
Rotate the head of the pivot bolt. For axle
alignment forward, rotate bolt head
clockwise. For axle alignment rearward,
rotate the bolt head counter-clockwise.
Both sides of axle need to be adjusted to
prevent axle rise or fall.
2. Align the front axle using the method
outlined in
Section 4-7.2 a.
3. After proper alignment has been obtained,
tighten the suspension pivot bolt nut to the
torque listed in the table in
Section 4-6.1
a.
4. Align the rear axle to the front axle. Locate
the rear axle equalizer beam pivot bolt in
hanger at front end of driver’s side rear axle
equalizer beam. Loosen the suspension
pivot bolt lock nut. Rotate the head of the
pivot bolt. For
axle alignment forward,
rotate bolt head clockwise. For axle
alignment rearward, rotate the bolt head
counter-clockwise. The rear axle should be
parallel with the front axle, with the
dimensions Y and Y1 being the same.
5. Tighten the suspension pivot bolt nut to the
torque listed in the table in
Section
4-6.1 a.
4-16