Section 4 • Repair Procedures
REV B
November 2005
Part No. 84700
GR-12 • GR-15 • GR-20
4 - 17
MAST COMPONENTS
3-2
Glide Pads
Glide pads, used on the GR-12 and GR-15, and
wear pads, used on the GR-20, are used to
provide a uniform fit between the columns as the
mast extends and retracts. Over time, it may be
necessary to adjust the glide pads to ensure good
machine performance.
Wear pads are not adjustable and do not require
servicing.
How to Adjust the Glide Pads
1 Locate the upper and lower glide pad
adjustment bolts below each upper roller bolt,
on both sides of each column.
2 Hold the glide pad adjustment bolt and loosen
the lock nut on all glide pads.
3 Turn the glide pad adjustment bolt clockwise
until the glide pad makes contact with the
column. Adjust the glide pads on both sides of
all columns. Be sure the sides of the columns
are even to within
1
/
8
inch / 3 mm of each other.
4 On the number 1 column, secure the upper and
lower glide pad bolts on both sides of the mast.
Hold the glide pad adjustment bolt and torque
the lock nut to 12 in-lbs / 1.35 Nm. Be sure the
glide pad bolt does not turn.
5 Repeat step 5 for the upper and lower glide
pads on both sides of the each column of the
mast, Start with the number 2 column and work
toward the carriage.
3-3
Lifting Chains
How to Adjust the Lifting Chains
1 Mark the column to be adjusted.
2 Raise the platform approximately 6 feet / 2 m.
3 Place a lifting strap of suitable capacity from an
overhead crane under the platform. Support the
platform. Do not apply any lifting pressure.
Component damage hazard. The
platform railings and platform
extension deck (if equipped) can
be damaged if they are used to lift
the platform. Do not attach the
lifting strap to the platform railings
or the platform extension deck.
4 Turn the adjustment lock nuts evenly on both
sides of the chain tension rocker clockwise to
raise the column or counterclockwise to lower
the column.
The chain tensioner rocker is
located near the bottom of each
column.
5 Fully lower the platform and confirm the
alignment of the columns. Repeat steps 2
through 5 if necessary.
6 Confirm that the chain tensioner bracket is
centered in the inspection hole.
a
lifting chain
b
chain terminal
c
chain tension rocker
d
adjustment lock nut
e
mast column
f
inspection hole
a
b
c
d
e
f
