Maxon GPTLR Series User manual

© MAXON Lift Corp. 2019
M-18-14
JANUARY 2019
To find maintenance & parts information for your GPTLR Liftgate, go to www.
maxonlift.com. Click the PRODUCTS, TUK-A-WAY & GPTLR buttons. Open the
Maintenance Manual in the PRODUCT DOCUMENTATION window. For parts,
click on the PARTS PORTAL, TUK-A-WAY & GPTLR buttons.

TABLE OF CONTENTS
WARNINGS........................................................................................................................... 4
SAFETY INSTRUCTIONS .................................................................................................... 5
NOTICE................................................................................................................................. 5
GPTLR LIFTGATE COMPONENTS...................................................................................... 6
GPTLR-SERIES INSTALLATION PARTS BOXES................................................................ 7
GPTLR-SERIES MANUALS & DECALS............................................................................... 8
VEHICLE REQUIREMENTS................................................................................................. 9
CENTER OF MASS ............................................................................................................ 15
STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE ....................................................... 16
BOLT EXTENSION PLATE.................................................................................................. 16
WELD EXTENSION PLATE (ALTERNATE METHOD)........................................................ 19
STEP 2 - WELD LIFTGATE TO VEHICLE ......................................................................... 21
STEP 3 - ATTACH OPTIONAL BATTERY BOX & FRAME TO VEHICLE (IF EQUIPPED). 25
STEP 4 - RUN POWER CABLE.......................................................................................... 32
STEP 5 - CONNECT POWER CABLE................................................................................ 34
STEP 6 - CONNECT GROUND CABLE ............................................................................. 36
STEP 7 - INSTALL CONTROL SWITCH ............................................................................. 38
STEP 8 - CHECKING HYDRAULIC FLUID......................................................................... 40
STEP 9 - CONNECT POWER CABLE TO BATTERY......................................................... 42
STEP 10 - REMOVE LOCKING BRACKETS & CHECK .......................................................... 43
FOR INTERFERENCE ........................................................................................................ 43
STEP 11 - ADJUST PLATFORM (IF REQUIRED)............................................................... 48
STEP 12 - FINISH WELDING LIFTGATE TO VEHICLE ..................................................... 57
STEP 13 - WELD TRUCK BODY TO FRAME..................................................................... 58
(TRUCKS ONLY)................................................................................................................ 58

STEP 14 - ADJUST OPENER (IF REQUIRED) .................................................................. 59
STEP 15 - ADJUST UNDERRIDE ...................................................................................... 62
STEP 16 - VEHICLE TAILLIGHT POSITIONING (IF REQUIRED)...................................... 76
ATTACH DECALS ............................................................................................................... 77
DECALS & PLATES ........................................................................................................... 78
ATTACH NONSKID & SAFETY STRIPING......................................................................... 79
TOUCHUP GALVANIZED FINISH ...................................................................................... 80
SYSTEM DIAGRAMS......................................................................................................... 81
PUMP & MOTOR SOLENOID OPERATION (GRAVITY DOWN)........................................ 81
PUMP & MOTOR SOLENOID OPERATION (POWER DOWN).......................................... 82
HYDRAULIC SCHEMATIC (GRAVITY DOWN)................................................................... 83
HYDRAULIC SCHEMATIC (POWER DOWN) .................................................................... 84
ELECTRICAL SCHEMATIC (GRAVITY DOWN) ................................................................. 85
CABLE WITH ...................................................................................................................... 85
175 AMP FUSE ...................................................................................................................85
ELECTRICAL SCHEMATIC (POWER DOWN) ................................................................... 86
GPTLR ELECTRICAL VALUES & TORQUE SPECIFICATIONS ........................................ 87
OPTIONS ............................................................................................................................ 88
OPTIONAL LIFTGATE COMPONENTS.............................................................................. 88
PRE-DELIVERY INSPECTION FORM................................................................................ 89

11921 Slauson Ave. Santa Fe Springs, CA. 90670 [phone] FAX [phone]
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Comply with the following WARNINGS and SAFETY INSTRUCTIONS while installing
Liftgates. See Operation Manual for operating safety requirements.
Installing and maintaining a liftgate can expose you to chemicals, including lead, which are known
to the State of California to cause cancer and birth defects or other reproductive harm. To mini-
mize exposure, install and maintain liftgate in a well-ventilated area and wear proper Personal
protective equipment (PPE). For more information go to www.P65Warnings.ca.gov.
WARNING
!
WARNINGS
•Do not stand, or allow obstructions, under the platform when lowering the Liftgate. Be sure your
feet are clear of the Liftgate.
• Keep fingers, hands, arms, legs, and feet clear of moving Liftgate parts (and platform
edges) when operating the Liftgate.
•Make sure vehicle battery power is disconnected while installing Liftgate. Connect vehicle
battery power to the Liftgate only when installation is complete or as required in the installation
instructions.
•If it is necessary to stand on the platform while operating the Liftgate, keep your feet and any
objects clear of the inboard edge of the platform. Your feet or objects on the platform can become
trapped between the platform and the Liftgate extension plate.
•Never perform unauthorized modifications on the Liftgate. Modifications may result in early failure
of the Liftgate and may create hazards for Liftgate operators and maintainers.
• Correctly stow platform when not in use. Extended platforms could create a hazard for
people and vehicles passing by.
WARNING
•Recommended practices for welding on steel parts are contained in the current AWS (American
Welding Society) D1.1 Structural Welding Code - Steel. Damage to Liftgate and/or vehicle, and
personal injury can result from welds that are done incorrectly.
!
•Recommended practices for welding galvanized steel are contained in the current AWS (Ameri-
can Welding Society) D19.0 Welding Zinc-Coated Steel. Damage to Liftgate and/or vehicle, and
personal injury can result from welds that are done incorrectly.

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SAFETY INSTRUCTIONS
SAFETY INSTRUCTIONS
•Comply with all WARNING and instruction decals attached to the Liftgate.
•Keep decals clean and legible. If decals are illegible or missing, replace them. Free replacement
decals are available from Maxon Customer Service.
•Consider the safety and location of bystanders and location of nearby objects when operating the
Liftgate. Stand to one side of the platform while operating the Liftgate.
•Wear appropriate safety equipment such as protective eyeglasses, faceshield and clothing while
performing maintenance on the Liftgate and handling the battery. Debris from drilling and contact
with battery acid may injure unprotected eyes and skin.
•Do not allow untrained persons or children to operate the Liftgate.
• Be careful working by an automotive type battery. Make sure the work area is well ventilated and
there are no flames or sparks near the battery. Never lay objects on the battery that can short the
terminals together. If battery acid gets in your eyes, immediately seek first aid. If acid gets on your
skin, immediately wash it off with soap and water.
• If an emergency situation arises (vehicle or Liftgate) while operating the Liftgate, release the con-
trol switch to stop the Liftgate.
•Read and understand the instructions in this Installation Manual before installing Liftgate.
•Before operating the Liftgate, read and understand the operating instructions in Operation
Manual.
• A correctly installed Liftgate operates smoothly and reasonably quiet. The only noticeable noise
during operation comes from the power unit while the platform is raised and lowered. Listen for
scraping, grating and binding noises and correct the problem before continuing to operate Liftgate.
NOTICE NOTICE
•Maxon Lift is responsible for the instructions to correctly install MAXON Liftgates on
trucks or trailers only.
•Liftgate installers, not Maxon Lift, are responsible for reviewing and complying with all
applicable Federal, State, and Local regulations pertaining to the trailer or truck.
•Installers of the liftgate should ensure that all trucks and trailers are equipped with grab
handles as needed. Refer to Technology Maintenance Council (TMC) RP 1428: Entry
And Egress Guidelines for Vehicles With Fold-Under Type Liftgates.

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GPTLR LIFTGATE COMPONENTS
NOTE: Make sure you have all components and parts before you start installing Liftgate.
Compare parts in the part box and each kit box with packing list enclosed in each
box. If parts and components are missing or incorrect call:
Maxon Customer Service
Call [phone] or
Send e-mail to [email protected]
GPTLR COMPONENTS
FIG. 6-1
LIFTGATE
!CAUTION
Unpacking the Liftgate on unlevel surface may allow heavy components to slide
off when shipping bands are cut. Injury and equipment damage could result.
Before the shipping bands are cut, put Liftgate on level surface that will support
1500 lbs. When unpacking the Liftgate, remove heavy components carefully to
avoid injury and damage.
PARTS
BOXES

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GPTLR-SERIES INSTALLATION PARTS BOXES
PARTS BOX B WITHOUT POWER CABLE, GROUND CABLE, OR FRAME CLIPS
TABLE 7-2
ITEM NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF PARTS BOX B 1 297318-01
1TOGGLE SWITCH ASSEMBLY 1 296855-01
2INSTALLATION BRACKET 2 269462-01
3HEX HEAD NUT, 1/2”-13 2 901011-9
4SHIM, PLATFORM ADJUSTMENT, 1/8” 2 281166-02
5SHIM, PLATFORM ADJUSTMENT, 1/16” 2 281166-01
6SCREW, SELF TAPPING, #10-24 X 1-1/2” LG 2 900057-7
7LUG, 2 GUAGE, COPPER, 5/16” 1 906497-02
8CAP SCREW, HEX HEAD, 1/2”-13 X 1-1/2” LG. 2 900035-3
PARTS BOX A WITH POWER CABLE
TABLE 7-1
PARTS BOX C WITH GROUND CABLE
TABLE 7-3
ITEM NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF PARTS BOX C 1 297502-02
1SPRING CLIP 20 050079
2PLASTIC TIE 4 206864
3GROMMET, 1” DIA, 2 HOLES 1 266428-09
4CABLE ASSY, 175 AMP 38 FT LG 1 264422
5GROUND CABLE ASSY, 2 GA X 38FT LG 1 269191-01
6#10 LOOM CLAMP 2 801681
7SELF-TAPPING SCREW, 10 X 1/2” LG. 2 030458
ITEM NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF PARTS BOX A 1 297502-01
1SPRING CLIP 10 050079
2PLASTIC TIE 2 206864
3#10 LOOM CLAMP 2 801681
4SCREW TAPPING #10 X 1/2” LG. 2 030458
5GROUND CABLE ASSEMBLY, 2GA, 48” LG 1 251871-26
6CABLE ASSEMBLY, 2GA, 49-3/4” LG. (GROUND) 1 268226-11
7CAP SCREW, 5/16”-18 X 3/4” LG 1 900009-3
8CABLE ASSEMBLY, 175A, 38 FT LG. 1 264422

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GPTLR-SERIES MANUALS & DECALS
ITEM NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF DECAL & MANUAL KIT 1
299460-01 (GPTLR-25)
299460-02 (GPTLR-33)
299460-06 (GPTLR-25, SWG EXT)
299460-05 (GPTLR-33, SWG EXT)
299459-01 (GPTLR-44)
299459-02 (GPTLR-55)
1INSTALLATION MANUAL 1 M-18-14
2OPERATION MANUAL 1 M-18-15
3DECALS (SEE DECAL PAGES IN THIS MANUAL) 1 (ALL GPTLR’S)
TABLE 8-1
NOTE: To find maintenance & parts information for your GPTLR Liftgate, go to
www.maxonlift.com. Open the Maintenance Manual in the PRODUCT
DOCUMENTATION window. For parts, click on the PARTS PORTAL, TUK-A-
WAY & GPTLR buttons.

11921 Slauson Ave. Santa Fe Springs, CA. 90670 [phone] FAX [phone]
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1. Check for correct clearances (FIGS. 9-1 and 9-2)
on vehicle to prevent interference between vehicle
and Liftgate. Refer to FIGS. 10-1, 11-1, and 11-2
for additional clearances and dimensions.
GPTLR-25 & -33 LIFTGATE CLEARANCE DIMENSIONS (FOR REFERENCE)
FIG. 9-1
36”
GPTLR-44 & -55 LIFTGATE CLEARANCE DIMENSIONS (FOR REFERENCE)
FIG. 9-2
VEHICLE REQUIREMENTS
NOTE:
• BODY maximum and minimum operating bed height for GPTLR-25, GPTLR-33,
GPTLR-44, & GPTLR-55 with standard platform:
Maximum height is 55” (Unloaded). Minimum height is 44” (Loaded). If Liftgate is
equipped with Canadian (CMVSS) underride, minimum height is 49”. Refer to
Canadian underrides listed in OPTIONS, and underride adjustment procedure.
• Make sure vehicle is parked on level ground while preparing vehicle and installing
Liftgate.
• On vehicle bodies equipped with swing open doors, the extension plate and vehicle
body must be modified to install this Liftgate.
• Dimensions are provided as reference for fitting Liftgate to vehicle body.
55” MAX. BED HEIGHT (UNLOADED)
44” MIN. BED HEIGHT (LOADED) 21-3/8” MAX.
10-3/8” MIN.
25-3/8”
23-1/4”
55” MAX. BED HEIGHT (UNLOADED)
44” MIN. BED HEIGHT (LOADED)
38”
21-3/4” MAX.
10-3/4” MIN.
24-1/2”
26-3/4”
14”
33-3/4”
36”
14”

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VEHICLE REQUIREMENTS - Continued
VEHICLE BODY CORNER POST CLEARANCE (FOR REFERENCE)
FIG. 10-1
BODY FLOOR
(REFERENCE)
5-5/8” (GPTLR-44/-55)
6-1/8” (GPTLR-25/-33)
LIFT ARM
BODY
CORNER POST

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VEHICLE REQUIREMENTS - Continued
GPTLR EXTENSION PLATE DIMENSIONS FOR 102” WIDE BODY
FIG. 11-2
102”
85”
1/2” 1/2”
GPTLR EXTENSION PLATE DIMENSIONS FOR 96” WIDE BODY
FIG. 11-1
96”
79”
4-7/16” (GPTLR-25 & -33)
5-7/16” (GPTLR-44 & -55)
1/2” 1/2”
4-7/16” (GPTLR-25 & -33)
5-7/16” (GPTLR-44 & -55)

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VEHICLE REQUIREMENTS - Continued
VEHICLE FRAME CUT FOR GPTLR-25 & GPTLR-33
FIG. 12-1
5”
12”
24”
TRUCK FRAME
BODY FLOOR
BODY CROSS
MEMBERS
REAR SILL
PLATFORM CLEARANCE CUTOUT AREA
(WITHIN DASHED LINES)
WOODEN SPACER
LONG SILL
2. Fit the Liftgate to vehicle body by cut-
ting vehicle frame as shown in FIGS.
12-1 or 13-1.
NOTE: The platform cutout area shown below applies to trucks and trailers. Typical
truck frame is shown. For installation on frameless trailers, kit must be select-
ed from the OPTIONAL COMPONENTS section in this manual.
NOTE: For Liftgates installed on trailers, refer to FIG. 14-1 for lift arm and platform
clearances on the rear sill. If necessary, remove the interfering portions of the
rear sill according to dimensions shown in FIG. 14-1 .
• To prevent aluminum platform from being damaged, make sure vehicle frame
is cut correctly and rear sills are modified if over 5” in height. If the cutouts
are incorrect, platform may hit vehicle frame or underbody when stowing the
Liftgate. The bottom of the platform may also hit the sill.
CAUTION
• Installer is responsible for ensuring that vehicle body and frame modifications
do not adversely affect the integrity of the body and frame.
NOTE: The dimensions, shown in the illustration below, are maximums except as
indicated.
NOTE: Refer to the platform clearance cutout area in FIGS. 12-1 and 13-1. Remove
any part of the rear sill that protrudes into this area.

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VEHICLE FRAME CUT FOR GPTLR-44 & GPTLR-55
FIG. 13-1
VEHICLE REQUIREMENTS - Continued
5-1/2”
13”
24”
TRUCK FRAME
BODY FLOOR
BODY CROSS
MEMBERS
REAR SILL
WOODEN SPACER
LONG SILL
PLATFORM CLEARANCE CUTOUT AREA
(WITHIN DASHED LINES)

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3. If necessary, cut trailer rear sill as
shown in FIG. 14-1.
VEHICLE REQUIREMENTS - Continued
REAR SILL CUTS FOR ALL GPTLR LIFTGATES
FIG. 14-1

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CENTER OF MASS
GPTLR-25 & GPTLR-33 CENTER OF MASS
(STOWED POSITION)
FIG. 15-1
12-3/4”
CENTER OF
MASS
8-1/2”
GPTLR-44 & GPTLR-55 CENTER OF MASS
(STOWED POSITION)
FIG. 15-2
CENTER OF
MASS
12-1/2”
8-1/2”

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STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE
1. Mark and drill holes into rear sill as shown in FIGS. 16-1 and 17-1.
REAR SILL - HOLE LOCATIONS FOR 96” WIDE VEHICLE
FIG. 16-1
USE 9/16” DRILL
(19 PLACES)
1-1/4”
3-1/8”
REAR
SILL
1-1/2”
19”
24”
14”
34”
41”
48”
55”
62”
72”
77”
82”
94-1/2”
96”
BOLT EXTENSION PLATE
NOTE: Liftgate extension plate comes with bolt holes so it can be bolted to vehicle
body with optional bolt kit. GRADE 8 bolts are required. MAXON recom-
mends getting the optional extension plate hardware kit listed in OPTIONS
section. Vehicle body must be drilled according to instructions. Extension
plate may also be welded to vehicle body. Do the following bolting or weld-
ing instructions for the extension plate.
CAUTION
To preserve the corrosion-resistant properties of the galvanized finish,
MAXON recommends bolting the galvanized extension plate to vehicle.
CAUTION
6-1/2” 6-1/2”
1-1/2”
1-1/4”

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REAR SILL - HOLE LOCATIONS FOR 102” WIDE VEHICLE
FIG. 17-1
1-1/4”
1-1/2”
27”
37”
44”
51”
58”
65”
75”
80”
85”
95-1/2”
100-1/2”
102”
22”
17”
STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE -
Continued
REAR
SILL
USE 9/16” DRILL
(19 PLACES)
6-1/2” 6-1/2”
3-1/8”

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2. Bolt extension plate to vehicle as shown in FIG. 18-1. If necessary, reposition ex-
tension plate so top surface is flush with top surface of sill. Then, torque bolts and
lock nuts to 105 +/-20 lb-ft.
NOTE: Do not tighten extension plate bolts and lock nuts until:
• All the bolts and lock nuts are in place.
• Mating surfaces of extension plate and rear sill are made flat as possible.
• Top of extension plate is flush with top of rear sill.
STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE -
Continued
CAUTION
The mating surface between the bolt-on extension plate and vehicle rear sill
must be as flat as possible. Interference between the mating surfaces could
result in a distorted top surface of extension plate when all the bolts are
tightened. Distorted extension plate can also make the dual steps difficult to
install correctly. Remove interference or shim rear sill to eliminate or reduce
the possibility of a distorted extension plate.
CAUTION
NOTE: Weld the LH and RH ends of the extension plate to vehicle body as shown
in FIG. 18-1 if any of the following conditions apply.
• Bolt holes are not accessible on the corner posts of the vehicle body.
• Liftgate will be used for dock loading applications.
• As required by body/trailer manufacturer
BOLTING EXTENSION PLATE (96” WIDE EXTENSION PLATE SHOWN)
FIG. 18-1
BOLTS
(KIT ITEMS)
EXTENSION
PLATE
VEHICLE
BODY
TEARDROP
LOCK NUTS
(KIT ITEMS)
3/16”
3/16”
WRAP WELD
HORIZONTAL
2” MIN/6” MAX
WRAP WELD
HORIZONTAL
2” MIN/ 6” MAX

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WELD EXTENSION PLATE (ALTERNATE METHOD)
STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE -
Continued
NOTE: Before welding extension plate to vehicle body, make sure:
• Inboard edge of extension plate is flush with the top of sill on vehicle body.
• Top surface of extension plate is level with the ground.
1. Center the extension plate on
vehicle body. Weld the extension
plate to vehicle body sill as shown
in FIGS. 19-1 and 20-1.
EXTENSION PLATE WELDS - VIEWED FROM ABOVE
FIG. 19-1
3/16”
3/16”
EXTENSION
PLATE
VEHICLE
BODY
3/16”
WELD LENGTH & SPACE:
2”- 11 3/4” ( 96”W VEHICLE)
2”- 12 1/2” (102”W VEHICLE)
To preserve the corrosion-resistant properties of the galvanized finish, MAX-
ON recommends bolting the galvanized extension plate to vehicle.
CAUTION
NOTE: For welding galvanized steel, refer to recommended practices as outlined in
AWS (American Welding Society) D19.0 Welding Zinc-Coated Steel.

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EXTENSION
PLATE
BRACKET
(2 PLACES)
BOLTING ON INSTALLATION BRACKETS
FIG. 20-2
CAP SCREW
1/2”-13 X 1-1/2” LG.
(2 PLACES)
HEX NUT
1/2”-13
(2 PLACES)
2. Bolt 2 installation brackets (parts bag items) on the
extension plate as shown in FIG. 20-2.Tighten hex
nuts securely.
EXTENSION PLATE WELDS - VIEWED FROM UNDERNEATH
FIG. 20-1
3/16”
EXTENSION
PLATE
VEHICLE
BODY
WELD LENGTH & SPACE:
2”- 11 3/4” ( 96”W VEHICLE)
2”- 12 1/2” (102”W VEHICLE)
NOTE: During installation of liftgate, installation brackets keep
the heel of the platform level with extension plate and
maintain a ¾” gap between extension plate and heel of
platform. The extension plate has bolt holes for bolting
on the installation brackets provided in parts box.
STEP 1 - ATTACH EXTENSION PLATE TO VEHICLE -
Continued