Maxon GPSLR Series User manual

M-18-08
SEPTEMBER 2020
REV A
© MAXON Lift Corp. 2020
To find maintenance & parts information for
your GPSLR Liftgates, go to www.maxon-
lift.com. Click the PRODUCTS, SLIDELIFT
and GPSLR buttons. Open the Maintenance
Manual in the PRODUCT DOCUMENTATION
window. For parts, click on the PARTS POR-
TAL, SLIDELIFT and GPSLR buttons.

TABLE OF CONTENTS
SUMMARY OF CHANGES: M-18-08, REVISION A............................................................. 4
WARNINGS........................................................................................................................... 5
SAFETY INSTRUCTIONS .................................................................................................... 6
NOTICE................................................................................................................................. 6
STANDARD LIFTGATE COMPONENTS .............................................................................. 7
GPSLR INSTALLATION PARTS BOX .................................................................................. 9
GPSLRT PARTS BOX ........................................................................................................ 10
(TRUCK REAR MOUNT)..................................................................................................... 10
GPSLR PARTS BOX (TRAILER REAR MOUNT) ................................................................11
VEHICLE REQUIREMENTS............................................................................................... 12
REAR IMPACT GUARD...................................................................................................... 15
STEP 1 - CHOOSE METHOD OF INSTALLATION............................................................. 16
STEP 2 - WELD LIFTGATE ON VEHICLE.......................................................................... 17
METHOD 1 - WELDING INSTALLATION PLATES FLUSH TO
TRAILER SLIDE RAIL ......................................................................................... 19
METHOD 2 - WELDING INSTALLATION PLATES TO
TRAILER SLIDE RAIL USING 1/4” SPACERS....................................................23
METHOD 3 - WELDING INSTALLATION PLATES TO
TRAILER CROSSMEMBERS.............................................................................. 28
METHOD 4 - WELDING INSTALLATION PLATES TO TRUCK CHASSIS.......... 33
STEP 3 -ATTACH CONTROL SWITCHES......................................................................... 36
STEP 4 - CONNECT POWER HARNESS TO JUNCTION BOX.........................................43
STEP 5 - RUN POWER CABLE.......................................................................................... 46
STEP 6 - CONNECTING POWER......................................................................................48
STEP 7 - PLATFORM ADJUSTMENT.................................................................................49
STEP 8 - FINAL BOLTING .................................................................................................. 53
STEP 9 -ATTACH SLIDINGAXLE STOPS (IF REQUIRED).............................................. 55

STEP 10 - ATTACH SAFETY CHAIN.................................................................................. 56
ATTACH DECALS ............................................................................................................... 59
DECAL POSITIONS............................................................................................................ 61
SYSTEM DIAGRAMS......................................................................................................... 63
PUMP & MOTOR SOLENOID OPERATION - SINGLE PUMP...........................................63
PUMP & MOTOR SOLENOID OPERATION - DUAL PUMPS ............................................64
HYDRAULIC SCHEMATIC - GRAVITY DOWN................................................................... 65
HYDRAULIC SCHEMATIC - POWER DOWN .................................................................... 66
ELECTRICAL SCHEMATIC - SINGLE PUMP.....................................................................67
ELECTRICAL SCHEMATIC - DUAL PUMP.........................................................................69
OPTIONS ............................................................................................................................ 71
OPTIONAL LIFTGATE COMPONENTS.............................................................................. 71
PRE-DELIVERY INSPECTION FORM................................................................................ 72

PAGE DESCRIPTION OF CHANGE
COVER Updated REV. and date of release.
5 Added California Proposition 65 WARNING.
49, 51, 52 Changed torque value for platform adjustment bolt to 100 lb-ft.
59 CAUTION decals were updated to show commonized GPSLR liftgate.
61 Parts decal with QR code was added for commonized GPSLR liftgate.
SUMMARY OF CHANGES: M-18-08, REVISION A

11921 Slauson Ave. Santa Fe Springs, CA. 90670 [phone] FAX [phone]
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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.
•Remove all rings, watches and jewelry before doing any electrical work.
Comply with the following WARNINGS and SAFETY INSTRUCTIONS while installing
Liftgates. See Operation Manual for operating safety requirements.
•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.
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
!

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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.
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 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.

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STANDARD LIFTGATE COMPONENTS
CAUTION
GPSLR TRUCK/TRAILER REAR MOUNT LIFTGATE COMPONENTS FOR SHIPMENT
(OPTIONAL COMPONENTS NOT SHOWN)
FIG. 7-1
!
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]
MAIN
ASSEMBLY
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 1750 lbs.
When unpacking the Liftgate, remove heavy components carefully to avoid injury
and damage.
PARTS
BOXES
INSTALLATION JIG
P/N 288831-01 (FOR 96” X 68”)
P/N 288831-02 (FOR 96” X 78”)

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MAIN
ASSEMBLY
STANDARD LIFTGATE COMPONENTS - Continued
GPSLRT TRUCK REAR MOUNT LIFTGATE COMPONENTS FOR SHIPMENT
(OPTIONAL COMPONENTS NOT SHOWN)
FIG. 8-1
PARTS
BOXES
INSTALLATION JIG
P/N 288831-01 (FOR 96” X 68”)
P/N 288831-02 (FOR 96” X 78”)

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GPSLR INSTALLATION PARTS BOX
INSTALLATION ON CROSSMEMBER
TABLE 9-1
NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF GPSLR INSTALLATION PARTS BOX 1 289259-01
1GUSSET, GPSLR MOUNT 12 268674-01
2PLATE, GPSLR SUPPORT 12 268675-01
3PLATE, GPSLR MOUNT 12 268676-01
NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF GPSLR INSTALLATION PARTS BOX 1 289259-02
1GUSSET, GPSLR MOUNT 12 268674-01
NOMENCLATURE OR DESCRIPTION QTY. PART NUMBER
REF GPSLR INSTALLATION PARTS BOX 1 289259-03
1GUSSET, GPSLR MOUNT 12 268674-01
2FLAT, 1/4” X 3-1/2” X 20” LG. 4 090148-10
INSTALLATION ON 48-1/8” SLIDE RAIL
TABLE 9-2
INSTALLATION ON 48-5/8” SLIDE RAIL
TABLE 9-3

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GPSLRT PARTS BOX
(TRUCK REAR MOUNT)
NOMENCLATURE OR DESCRIPTION QTY. PART
NUMBER
REF PARTS BOX, SLIDER 1 289101-01
1HEX FRAME BOLT 1/2”-13 X 1-1/2” LG. 16 901024-5
2FLAT WASHER, 1/2” 16 902013-13
3FLANGE LOCK NUT, GRADE G 16 901023
4MAIN CONTROL SWITCH 1 289001-01
5CONTROL SWITCH MOUNTING BRACKET 1 289134-01G
6BUTTON SCREW, 1/4”-20 X 1” LG. 2 900719-07
7NYLON INSERT STOP NUT, 1/4”-20 2 903137-01
8FLAT WASHER, 1/4” 2 903412-01
9CONTROL SWITCH ASSEMBLY 1 289353-01
10 DECAL SHEET, UP/DOWN 1 299038-01
11 INTERNAL SWITCH MOUNTING BRACKET, GALVANIZED 1 289255-01G
12 SELF TAPPING SCREW,10-24 X 1/2” LG. 4 900766-02
13 FLAT WASHER, #10 6 903444-01
14 BUTTON SCREW, 10-24 X 1-1/2” LG. 2 900722-09
15 NYLON INSERT NUT, THIN, 10-24 2 903129-01
16 CABLE TIE, SCREW MOUNT, 1-1/2” DIA. 5 905398-01
17 SELF-DRILLING SCREW, #6-20 5 900818-01
18 STOW FLASHING LIGHT KIT, 40’ 1 289355-01
19 SAFETY STOW CHAIN, GPSLR 1 287132-01
20 FUSE HOLDER ASSEMBLY, 10 AMP, 3/8” RING 1 285013-04
21 CIRCUIT BREAKER KIT, 175 AMPS, 30 VDC 1 289723-01
22 PLASTIC TIE, 7” LG. 20 205780
TABLE 10-1

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GPSLR PARTS BOX
(TRAILER REAR MOUNT)
TABLE 11-1
NOMENCLATURE OR DESCRIPTION QTY. PART
NUMBER
REF PARTS BOX, SLIDER 1 289101-02
1HEX FRAME BOLT 1/2”-13 X 1-1/2” LG. 16 901024-5
2FLAT WASHER, 1/2” 16 902013-13
3FLANGE LOCK NUT, GRADE G 16 901023
4MAIN CONTROL SWITCH 1 289001-01
5CONTROL SWITCH MOUNTING BRACKET 1 289134-01G
6BUTTON SCREW, 1/4”-20 X 1” LG. 2 900719-07
7NYLON INSERT STOP NUT, 1/4”-20 2 903137-01
8FLAT WASHER, 1/4” 2 903412-01
9CONTROL SWITCH ASSEMBLY 1 289353-01
10 DECAL SHEET, UP/DOWN 1 299038-01
11 INTERNAL SWITCH MOUNTING BRACKET, GALVANIZED 1 289255-01G
12 SELF TAPPING SCREW,10-24 X 1/2” LG. 4 900766-02
13 FLAT WASHER, #10 6 903444-01
14 BUTTON SCREW, 10-24 X 1-1/2” LG. 2 900722-09
15 NYLON INSERT NUT, THIN, 10-24 2 903129-01
16 CABLE TIE, SCREW MOUNT, 1-1/2” DIA. 5 905398-01
17 SELF-DRILLING SCREW, #6-20 5 900818-01
18 STOW FLASHING LIGHT KIT, 60’ 1 289355-02
19 SAFETY STOW CHAIN, GPSLR 1 287132-01
20 FUSE HOLDER ASSEMBLY, 10 AMP, 3/8” RING 1 285013-04
21 CIRCUIT BREAKER KIT, 175 AMPS, 30 VDC 1 289723-01
22 PLASTIC TIE, 7” LG. 20 205780

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VEHICLE REQUIREMENTS
Check for correct clearances (FIGS. 14-1, 14-2, 15-1 and 15-2) on vehicle to prevent
interference between vehicle and Liftgate.
NOTE: Make sure vehicle is parked on level ground while preparing vehicle and
installing Liftgate.
NOTE: BODY maximum and minimum operating bed height:
Maximum height is 60” (Unloaded). Minimum height is 46” (Loaded).
On vehicle bodies equipped with swing-open doors, the platform
may have to be modified to install this Liftgate.
NOTE: Dimensions are provided as reference for fitting Liftgate to vehicle body. For
detailed ground clearance information, refer to the WELD INSTALLATION
PLATE procedure in this manual.
CAUTION
The sliding axle assembly on a trailer can collide with a Liftgate mounted
on the slide rails. To prevent damage to Liftgate and trailer, install stops on
the slide rails to keep the sliding axles from hitting Liftgate. Refer to Liftgate
clearance dimensions in this section of the manual.
14” MAX
47-1/8”
NOTE: For installation of this Liftgate, the maximum allowable
thickness of the vehicle body rear sill is 14”.
OVERALL WIDTH OF GPSLR LIFTGATE & MOUNTING FRAME
FOR 96” WIDE VEHICLE
FIG. 12-1
REAR SILL
96”

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VEHICLE REQUIREMENTS - Continued
47-7/8”
REAR SILL
102”
OVERALL WIDTH OF GPSLR LIFTGATE & MOUNTING FRAME
FOR 102” WIDE VEHICLE
FIG. 13-1
14”

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5-1/2” FLOOR (SHOWN)
VEHICLE REQUIREMENTS - Continued
60” MAX. BED HEIGHT
46” MIN. BED HEIGHT
14”
MAX
12” TO 26”
CLEARANCES FOR GPSLR WITH 68” TO 78” SLIDE RAILS (TRUCK)
FIG. 14-1
4-3/16”
68” TO 78”
REAR
SILL
34” 26-1/8”
22” MAX
11” TO 26”
CLEARANCES FOR GPSLR WITH 68”- 78” SLIDE RAILS (TRAILER)
FIG. 14-2
5-1/2”
68” TO 78”
34”
26-1/8”
22” MAX
3” CROSS MEMBERS (SHOWN)
4-3/16” FLOOR (SHOWN)
4” CROSS MEMBERS (SHOWN)
14” MAX
10-3/4”
(X2)
60” MAX. BED HEIGHT
46” MIN. BED HEIGHT
10-1/2”
(X2)
REAR
SILL

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VEHICLE REQUIREMENTS - Continued
REAR IMPACT GUARD
REQUIRED REAR-END CLEARANCES OF REAR IMPACT GUARD
FIG. 15-1
REQUIRED GROUND & SIDE CLEARANCES OF REAR IMPACT GUARD
FIG. 15-2
0-1/4”
REAR EXTREMITY
OF VEHICLE
NOTE: The stowed GPSLR platform functions as a rear impact guard for vehicle.
To comply with current Canadian Motor Vehicle Safety Standards (CMVSS
223), the rear impact guard must be within the rear-end, side, and ground
clearances shown in FIGS. 15-1 & 15-2.
PLATFORM
(REAR IMPACT GUARD)
4” MAX. 4” MAX.
SIDE EXTREMITY
OF VEHICLE SIDE EXTREMITY OF VEHICLE
PLATFORM
22” MAX.
PLATFORM

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STEP 1 - CHOOSE METHOD OF INSTALLATION
Four methods for mounting a GPSLR Liftgate on a truck or trailer chassis are covered in
this manual. Method 1 is the preferred standard method of installation.
METHOD 3 - For mounting installation plates on
crossmembers (FIG. 16-3) using
gussets (Kit items) supporting slide
rail, refer to WELDING INSTALLA-
TION PLATES TO TRAILER,
METHOD 3 instructions in
STEP 2.
FIG. 16-1
FIG. 16-4
FIG. 16-2
FIG. 16-3
INSTALLATION ON REAR OF TRAILER
METHOD 2 - For mounting installation plates on
inside slide rail (FIG. 16-2) using 1/4”
spacers (Kit items) and gussets (Kit
items) supporting slide rail, refer to
WELDING INSTALLATION PLATES
TO TRAILER, METHOD 2 instruc
tions in STEP 2.
METHOD 1 - For mounting installation plates flush
against slide rail (FIG. 16-1) using
gussets (Kit Items) supporting slide
rail, refer to WELDING INSTALLA-
TION PLATES TO TRAILER,
METHOD1 instructions inSTEP2.
METHOD 4 - For mounting installation plates to
vehicle chassis (FIG. 16-4), refer to
WELDING INSTALLATION PLATES
TO TRUCK BODY, METHOD 4
instructions in STEP 2.
INSTALLATION ON REAR OF TRUCK

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NOTE: Liftgate must be welded to at least 6 fixed trailer crossmembers that are
typically spaced 12” between centers.
CAUTION
To avoid personal injury, use at least 2 people to position Liftgate.
!
NOTE: For installation of this Liftgate, the maximum distance from bottom of trailer
cross members to top of trailer floor is 10-1/2” max.
NOTE: Ideal installation is for edge of platform to be aligned with rear door
opening.
NOTE: Switches, stow mechanism, latch release handle and platform latch may
be located on either side of the Liftgate during installation, depending on
location of trailer door hinges.
Use weld blankets to protect lines and tubes from weld splatter.
WARNING
!
`
Welding on galvanized parts gives off especially hazardous fumes. To mini-
mize hazard remove galvanizing from weld area, provide adequate ventilation,
and wear suitable respirator.
!
WARNING
STEP 2 - WELD LIFTGATE ON VEHICLE

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1. With forklift, position the Liftgate centered to the rear
of vehicle (FIGS. 18-1 & 18-1A).
POSITIONING LIFTGATE TO VEHICLE
FIG. 18-1
STEP 2 - WELD LIFTGATE ON VEHICLE - Continued
FORKLIFT
JIG
FIG. 18-1A
2. Cover Liftgate with welding blanket (FIG. 18-2).
COVERING LIFTGATE WITH WEDLING BLANKET
FIG. 18-2
WELDING BLANKET

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METHOD 1 - WELDING INSTALLATION PLATES FLUSH TO
TRAILER SLIDE RAIL
NOTE: Method 1 instructions are intended for mounting Liftgate installation plates
(Kit items), on a trailer, flush against slide rail using supporting gussets (Kit
items). Reference FIG. 19-1.
1. Mark position for placement of installation
plates on trailer frame as shown in
FIG. 19-2.
INSTALLING INSTALLATION PLATES FLUSH AGAINST SLIDE RAIL
FIG. 19-1
SLIDE RAIL
INSTALLATION PLATE
SLIDE RAIL
INSTALLATION PLATE
48-1/8”
47-7/8”
MARKING POSITION FOR INSTALLATION PLATES
FIG. 19-2
10-1/2”
(2 PLACES)
REAR SILL
TRAILER FLOOR
SLIDE RAIL
NOTE: Although installation plates are attached to Liftgate, for clarity, Liftgate is
not shown on following images.
STEP 2 - WELD LIFTGATE ON VEHICLE - Continued

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2. Line up end of LH installation plate with the position
mark on the slide rail. Clamp installation plate to LH
slide rail (FIG. 20-1).
CAUTION
To avoid personal injury, use at least 2 people to
position the installation plate.
!
CLAMPING INSTALLATION PLATE TO SLIDE RAIL
FIG. 20-1
LH SLIDE RAIL
INSTALLATION PLATE
CLAMP
(3 PLACES)
STEP 2 - WELD LIFTGATE ON VEHICLE - Continued
METHOD 1 - WELDING INSTALLATION PLATES FLUSH TO
TRAILER SLIDE RAIL - Continued