Thern 548 User manual

Read this Own
er’s Manual
thoroughly before operating
the equip
ment. Keep it with
the equip
ment at all times.
Replacements are available
from Thern, Inc.
Owner’s Manual
For
Model 548
Floor Crane
IMPORTANT: Please record
product information on
page 2. This information is
required when calling the
factory for service.
A6759C-0912
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 2
A6759C-0912
Two-Year Limited Warranty
Thern, Inc. warrants its products against defects in material or workmanship for two years from the date of purchase
by the original using buyer, or if this date cannot be established, the date the product was sold by Thern, Inc. to the
dealer. To make a claim under this warranty, contact the factory for an RGA number. The product must be returned,
prepaid, directly to Thern, Inc., 5712 Industrial Park Road, Winona, Minnesota 55987. The following information
must accompany the product: the RGA number, the date of purchase, the description of the claimed defect, and a com-
plete explanation of the circumstances involved. If the product is found to be defective, it will be repaired or replaced
free of charge, and Thern, Inc. will reimburse the shipping cost within the contiguous USA.
This warranty does not cover any damage due to accident, misuse, abuse, or negligence. Any alteration, repair or
modification of the product outside the Thern, Inc. factory shall void this warranty. This warranty does not cover any
costs for removal of our product, downtime, or any other incidental or consequential costs or damages resulting from
the claimed defects. This warranty does not cover brake discs, wire rope or other wear components, as their life is
subject to use conditions which vary between applications.
FACTORY AUTHORIZED REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE
EXCLUSIVE REMEDY TO THE CONSUMER. THERN, INC. SHALL NOT BE LIABLE FOR ANY INCIDENTAL
OR CONSEQUENTIAL DAMAGES FOR BREACH OF ANY EXPRESS OR IMPLIED WARRANTY ON THIS
PRODUCT. EXCEPT TO THE EXTENT PROHIBITED BY APPLICABLE LAW, ANY IMPLIED WARRANTY
OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ON THIS PRODUCT IS LIMITED IN
DURATION TO THE DURATION OF THIS WARRANTY.
Some states do not allow the exclusion or limitation of incidental or consequential damages, or allow limitations on
how long an implied warranty lasts, so the above limitation or exclusion may not apply to you. This warranty gives
you specific legal rights, and you may also have other rights which vary from state to state.
Note: Thern, Inc. reserves the right to change the design or discontinue the production of any product without
prior notice.
About This Manual
The Occupational Safety and Health Act of 1970 states that it is the employer’s
responsibility to provide a workplace free of hazard. To this end, all equipment
should be installed, operated, and maintained in compliance with applicable trade,
industrial, federal, state, and local regulations. It is the equipment owner's respon-
sibility to obtain copies of these regulations and to determine the suitability of the
equipment to its intended use.
This Owner’s Manual, and warning labels attached to the equipment, are to serve
as guidelines for hazard-free installation, operation, and maintenance. They
should not be understood to prepare you for every possible situation.
The information contained in this manual is applicable only to the Thern Model
548 Floor Crane. Do not use this manual as a source of information for any other
equipment.
The following symbols are used for emphasis throughout this manual:
Failure to follow ‘WARNING!’ instructions may result in equipment damage,
property damage, and/or serious personal injury.
Failure to follow ‘CAUTION!’ instructions may result in equipment damage,
property damage, and/or minor personal injury.
Important!
Failure to follow ‘important!’ instructions may result in poor performance of
the equipment.
Please record the following:
Date Purchased:
Crane Model No.:
Crane Serial No.:
This information is required when
calling the factory for service.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 3
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Suggestions for Safe Operation
DO the following:
Read and comply with the guidelines set forth in this Owner’s Manual. Keep
this manual, and all labels attached to the crane, readable and with the
equipment at all times. Contact Thern, Inc. for replacements.
Check lubrication before use.
Use a sling or other approved lifting device.
Keep hands away from moving parts of the equipment.
Keep all unnecessary personnel away from crane while in operation.
DO NOT do the following:
Do not lift people, or things over people. Do not walk or work under a load or
in the line of force of any load.
Do not exceed the load rating of the crane or any other component in
the system. To do so could result in failure of the equipment.
Do not use more than one crane to move a load that exceeds the load rating of
a single crane. A shift in load weight could overload the equipment.
Do not use damaged or malfunctioning equipment. To do so could result in
failure of the equipment.
Do not modify the equipment in any way. To do so could cause
equipment failure.
Do not divert your attention from the operation. Stay alert to the possibility of
accidents, and try to prevent them from happening.
Do not jerk or swing the load. Avoid shock loads by starting and stopping the
load smoothly. Shock loads overload the equipment and may cause damage.
Do not use the crane to drag or pull loads. This will create side pulls which
could damage the equipment or cause the load to tip.
Do not leave a suspended load unattended. Place the load on the ground if it
must be left unattended.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

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Important!
• Inspect the crane during assem-
bly according to the Instructions
for Periodic Inspection. This will
give you a record of the condition
of the crane with which to com-
pare future inspections.
• Save all boxes and crates that the
crane was shipped in, use them
again if you need to repackage
the crane.
• Contact the factory immediately if
any parts are missing or damaged.
• Do not overtighten fasteners, this
may strip threads or cause dam-
age to other parts.
1.1 Assembling the Crane
When the boom is released from its folded position, it moves rapidly and with
force. Keep the area in front of the boom (between the crane legs) clear of any
obstruction when releasing the boom.
1.1.1 OPEN CARTON and thoroughly check contents against parts list.
1.1.2 STUDY PARTS DRAWINGS to understand how the crane is assembled.
See page 15.
1.1.3 ITEMS 1, 9, 22 and 23 have been factory assembled using items 4, 5, 7, 8,
10, 11, 12, 13, 14, 15, 18, 24, 25 and 26.
1.1.4 LUBRICATE PINS and other components prior to assembly. See Section
3.2 Lubricating the Crane.
1.1.5 ASSEMBLE THE CRANE
a ASSEMBLE THE SWIVEL CASTERS (item 2) to the crane with 5/16" x
3/4" cap screws (item 3), 5/16" lock washers (item 5) and 5/16" hex nuts
(item 4).
b ASSEMBLE THE WHEELS (item 6) at the ends of the legs (item 20 and
21) using the axle bolts (item 19).
c ASSEMBLE THE HANDLE (item 28) onto the frame weldment (item 1)
with 5/16" x 1" cap screw (item 26), 5/16" lock washer (item 5) and 5/16"
hex nut (item 4).
d ASSEMBLE HANDLE GRIPS (item 27) onto handle.
e SLIDE THE LEGS into the frame of the crane as shown on the drawing. Be
sure they are assembled properly so the wheels are parallel with each other.
Secure the legs with the leg pin assembly (item 7), which is attached to the
frame with cables.
f THE CRANE IS DESIGNED to fold up into a compact package for storage
and transport. It is folded when shipped from the factory.
• To release the boom to its working position, turn the release valve coun-
terclockwise until the boom pops out to its working position.
• Turn the release valve clockwise until it is tight and use the jack handle to
operate jack to move the boom to a horizontal position.
g PLACE JACK HANDLE in its holster.
h ASSEMBLE THE SWIVEL HOOK weldment (item 16) to the boom exten-
sion (item 23) with the swivel pin (item 17). Secure the swivel pin with two
5/32" x 1" cotter pins (item 18).
1.1.6 CHECK CRANE over to see that all bolts are tight and all cotter pins bent to
secure. See figure 1.
Figure 1 – Cotter Pins
bend arms back
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 5
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Important!
• It is your responsibility to detect
and account for different fac-
tors affecting the condition and
performance of the equipment.
2.1 General Theory of Operation
Avoid shock loads created by quickly opening and closing the release valve as
a load is being lowered. Shock loads may overload the hydraulic circuit and
cause damage to the jack.
2.1.1 THE FORCE REQUIRED to move the load must not exceed the load rat-
ing of the crane. Consider the total force required to move the load, not the
weight of the load.
2.1.2 THIS EQUIPMENT CAN develop forces that will exceed the load rating.
It is the responsibility of the equipment user to limit the size of the load.
Inspect the equipment regularly for damage according to the instructions
contained in this manual.
2.1.3 PERFORMANCE RATINGS of the equipment are affected by the position
of the boom.
a LOAD RATING represents the maximum load that can be placed on new
equipment. Load ratings are assigned values for specific boom positions.
The load rating decreases as you increase boom length.
b LIFT HEIGHT AND REACH vary with the position of the boom.
2.1.4 DUTY RATINGS refer to the type of use the equipment is subject to. Con-
sider the following when determining duty rating.
a ENVIRONMENT: harsh environments include hot, cold, dirty, wet, cor-
rosive, or explosive surroundings. Protect the equipment from harsh envi-
ronments when possible.
b MAINTENANCE: poor maintenance, meaning poor cleaning, lubrication,
or inspection, leads to poor operation and possible damage of the equipment.
Minimize poor maintenance by carefully following the instructions con-
tained in this manual.
c LOADING: severe loading includes shock loading and moving loads that
exceed the load rating of the equipment. Avoid shock loads, and do not
exceed the load rating of the equipment.
d FREQUENCY OF OPERATION: frequent or lengthy operations increase
wear and shorten the life span of bearings, sheaves, and other components.
Increase maintenance of the equipment if used in frequent operations.
e WHEN NOT IN USE, always leave the hydraulic jack ram all the way
down.
CONTACT THE FACTORY FOR MORE INFORMATION.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 6
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2.2 Preparing for Operation
Do not use the crane in an area defined as hazardous by the National Electric
Code, unless use in such an area has been thoroughly approved.
Do not use the crane near corrosive chemicals, flammable materials, explo-
sives, or other elements that may damage the crane or injure the operator.
Adequately protect the crane and the operator from such elements.
Use the crane on a rigid and level surface that will support the crane and its
load under all load conditions, including shock loading.
2.2.1 CONSIDER THE OPERATION. Do not begin until you are sure you can
perform the entire operation without hazard.
2.2.2 INSPECT ALL COMPONENTS of the system.
a INSPECT THE CRANE and other equipment according to the Instructions
for Frequent Inspection.
b OPERATORS must be in good health, alert, thoroughly trained in operat-
ing the equipment, and properly clothed (hard hat, safety shoes and safety
glasses, no loose clothing).
c THE LOAD must be clear of other objects and free to move. Make sure the
load will not tip, spin, roll away, or in any way move uncontrollably.
2.2.3 KNOW YOUR LOAD and make sure you do not exceed the load rating of
the crane or any other equipment in the system.
2.2.4 POSITION THE CRANE AND BOOM so the load hook is centered over
the load. Avoid side pulls which could damage the crane or cause the
load to tip. See figure 2.
2.2.5 ADJUSTING THE BOOM. See figure 2.
aREMOVE ANY LOAD from the crane and disengage hook from load.
bLOCATE BOOM in horizontal position to make adjustment easier.
cREMOVE BOOM EXTENSION PIN and adjust boom extension to desired
position, then re-insert pin. The boom extension pin must be removed only
when adjustments are being made. It must always be re-installed immediately.
2.2.6 TO PURGE AIR FROM THE JACK.
aOPEN THE RELEASE VALVE by turning the handle in a counterclockwise
direction two full turns.
bPUMP THE HANDLE 10 full strokes.
cCLOSE THE RELEASE VALVE by turning the handle in a clockwise direc-
tion until tight.
dPUMP THE JACK until the ram is extended to maximum height.
eIF THE CONDITION SEEMS BETTER but is still detectable, repeat steps
"a" through "d" until all the air is purged from the system.
Important!
• When determining whether the
load will exceed the load rating,
consider the total force required
to move the load.
Figure 2 – Positioning the
Boom
correct
center line
boom extension pin
boom extension pin
center line
incorrect
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 7
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2.3 Attaching the Load
2.3.1 CLEAR OBJECTS from the path you will travel, so you can move freely
and observe the load at all times during the operation.
2.3.2 ATTACH THE LOAD using a nylon sling, or other approved lifting device.
Follow the recommendations of the sling manufacturer.
a SEAT THE SLING in the saddle of the hook with the hook latch completely
closed. See figure 3.
b CENTER THE LOAD on the hook so it will remain balanced and not tip or
rotate to one side.
2.4 Moving the Load
2.4.1 LIFT THE LOAD slowly and smoothly. Make sure the load is balanced and
securely attached before lifting. See figure 4.
2.4.2 OPERATE THE HYDRAULIC JACK to raise or lower the load.
a RAISE THE LOAD by smoothly pumping the hydraulic jack with the han-
dle. With new equipment, a whining noise may occur when pumping.
b LOWER THE LOAD by slowly turning the release valve counterclockwise.
Too many full turns will unscrew the valve and release oil.
cClose the valve by tightening it clockwise.
2.4.3 PULL THE CRANE BACKWARD to move the load, with the load close to
the floor and tied to the mast and legs to prevent swinging. See figure 4.
2.4.4 MOVE THE LOAD slowly and smoothly, especially when making turns.
2.4.5 MOVE THE CRANE BY HAND ONLY. Do not use powered devices to
push or pull the crane.
Important!
• Obey a stop signal from anyone.
• Appoint a supervisor if more
than one person is involved in
the operation. This will reduce
confusion and increase safety.
• When lifting or moving the
load, use a tag line to keep the
load from swinging or twisting,
while keeping yourself away
from the load.
Figure 3 – Attaching Load
latch closed
tight against
hook
sling seated in
saddle of hook
Figure 4 – Moving the Load
correct incorrect
obstruction
boom in lowest
travel position
approved lifting
device or sling
load secured to
prevent swinging
or spinning
swinging load
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 8
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3.1 Cleaning the Crane
Clean the crane to remove dirt and help prevent rust and corrosion.
3.1.1 CLEAN THE CRANE every six months or whenever it is dirty.
a WIPE ALL EQUIPMENT to remove dirt and grease.
b LEAVE A LIGHT FILM of oil on all surfaces to protect against rust
and corrosion.
c WIPE OFF excessive amounts of oil to avoid the accumulation of dirt.
3.1.2 REMOVE UNNECESSARY OBJECTS from the area surrounding
the crane.
3.2 Lubricating the Crane
Lubricate the crane properly to help protect it from wear and rust. Read the
following instructions carefully.
Partial disassembly may be required to lubricate the crane properly to help
protect from wear and corrosion.
3.2.1 LUBRICATE THE WHEELS at least every 6 months. Use a grease brush to
apply a light film of NLGI #2 grease to the roller bearings on the rear caster
wheels. Apply 2 to 3 drops of 150 grade gear oil to the shafts on the front
wheels, rotate the wheels to allow oil to penetrate, and wipe off excess oil to
avoid accumulation of dirt.
3.2.2 LUBRICATE ALL PINS at least every 6 months. Use a grease brush to ap-
ply a light film of NLGI #2 grease to all pins.
3.2.3 LUBRICATE THE SWIVEL HOOK at least every 6 months. Apply 2 to
3 drops of 150 grade gear oil, rotate the hook to allow oil to penetrate, and
wipe off excess oil to avoid accumulation of dirt.
a IT SHOULD NOT BE NECESSARY to refill or top off the reservoir with
hydraulic fluid unless there is an external leak. An external leak requires im-
mediate repair which must be performed in a dirt-free environment by quali-
fied hydraulic repair personnel who are familiar with this equipment.
3.2.4 LUBRICATE THE JACK pivot pins and other moving parts after 10 cycles.
3.2.5 LUBRICATE EQUIPMENT by following the manufacturers recommenda-
tions.
Important!
Increase the frequency of mainte-
nance procedures if the crane is:
• Operated for long periods.
• Used to lift heavy loads.
• Operated in wet, dirty, hot, or
cold surroundings.
Important!
• Make sure lubricant has a tem-
perature rating appropriate for
the ambient temperatures of the
operation.
Important!
• In order to prevent seal dam-
age and jack failure, never use
alcohol, hydraulic brake fluid or
transmission oil in the jack. Use
Chevron Hydraulic Oil AW ISO
32 or its equivalent Unocal Unax
AW 150.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 9
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3.3 Inspecting the Equipment
Do not use damaged or malfunctioning equipment. Place an “OUT OF ORDER”
sign on the crane. Do not use the crane until the sign is removed by a qualified
maintenance person who has completely corrected the problem.
Inspect the crane to detect signs of damage or poor operation before they
become hazardous.
3.3.1 CONSULT APPLICABLE CODES AND REGULATIONS for specific
rules on inspecting the crane and other equipment.
3.3.2 Instructions for Frequent Inspection
a VISUALLY INSPECT the entire crane and all other equipment involved in
the operation.
• Check all equipment for cracks, dents, bending, rust, wear, corrosion and
other damage.
• Make sure the entire crane is properly lubricated.
• Make sure all fasteners are tight and secure.
• Make sure the surface under the crane is in good condition, and capable
of supporting the crane and its load under all load conditions.
b TEST CRANE PERFORMANCE by operating the crane with a load not
exceeding the load rating.
• Listen for unusual noises, and look for signs of damage as you operate the
crane.
• Make sure the hydraulic jack raises and lowers the load smoothly, without
hesitation or strain.
• Make sure the floor crane rolls smoothly and freely, without swerving or
binding.
• To remove air from the jack insert handle onto release valve and turn
counterclockwise no more than 3 turns. Place handle in handle socket and
pump handle 6 to 8 strokes. Repeat as required.
Completely correct all problems before continuing. Use the Troubleshooting
Chart to help determine the cause of certain problems. See table 2.
Important!
• Start an inspection program as
soon as you put the crane into use.
• Appoint a qualified person to be
responsible for regularly in-
specting the equipment.
• Keep written records of in-
spection. This allows comparison
with comments from previous in-
spections so you can see changes
in condition or performance.
Perform frequent inspections:
• Before each operation.
• Every 3 hours during operation.
• Whenever you notice signs of
damage or poor operation.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 10
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3.3.4 Instructions for Periodic Inspection
a VISUALLY INSPECT THE CRANE and all other equipment. Disassemble
the crane as necessary to inspect individual components.
• Check the finish for wear, flaking, or other damage.
• Check all equipment for cracks, dents, bending, rust, wear, corrosion and
other damage. If the equipment was overloaded, or if you notice cracks
and other signs of overloading and damage promptly remove equipment
from use and have it repaired or replaced. DO NOT CONTINUE TO
USE DAMAGED OR OVERLOADED EQUIPMENT.
• Check all fasteners for stripped threads, wear, bending, and other damage.
• Measure the throat opening, thickness, and twist of the hook. Replace the
hook if it shows signs of damage. See figure 5.
• Make sure hook latch opens without binding and closes when released.
• Check the hydraulic jack for leaks, bending, wear, and other damage.
• Make sure the entire crane is properly lubricated.
• Make sure all labels and plates are readable, firmly attached, free of dam-
age and clean. Replacements are available from the factory.
b TEST CRANE PERFORMANCE by operating the crane with a test load
equal not exceeding the load rating.
• Listen for unusual noises and look for signs of damage as you operate the
crane.
• Make sure the hydraulic jack raises and lowers the load smoothly, without
hesitation or strain.
• Make sure the crane rolls smoothly and freely, without swerving or binding.
Completely correct all problems before continuing. Use the Troubleshooting
Chart to help determine the cause of certain problems. See table 2.
Perform periodic inspections:
• Every 6 months.
• Whenever you return the crane to
service from storage.
• Whenever you notice damage
or poor operation in a frequent
inspection.
• Whenever you have, or think you
may have, overloaded or shock
loaded the crane.
twist
throat
opening
thickness
Figure 5 – Load Hook
Inspection
The wire rope assembly must be
replaced if the throat opening is
15% wider than nominal, if the
thickness is 10% less than nomi-
nal, or if the hook is twisted 10°
or more.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 11
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Table 1 – Inspection Checklist
damages problems
general finish weathered, flaking, otherwise damaged equipment not properly lubricated
parts cracked, bent, rusted, worn, otherwise damaged unusual noises, other signs of malfunction
fasteners stripped threads, bent, worn, otherwise damaged loose, not tightened to the proper torque
wheels cracked, nicked, otherwise damaged not securely attached
hydraulic jack leaks oil, cracked, bent, worn, otherwise damaged oil contaminated, or not filled with proper oil
load hook twisted, bent, worn, otherwise damaged, see figure 5 hook latch fails to close when released
replace if twist is 10 degrees or more twist =
replace if throat width is 15% larger than nominal throat width =
replace if thickness is 10% less than nominal thickness =
labels and plates dirty, illegible, otherwise damaged loosely attached or missing
comments:
authorized signature: date
checked boxes indicate damage or problem in need of repair
Table 2 – Troubleshooting Chart
problem cause correction
crane will not lift or hold load • load too heavy lighten load
• hydraulic jack release valve not closed turn valve clockwise to close
• hydraulic fluid level low inspect and lubricate as necessary
• hydraulic jack leaks oil inspect and repair as necessary
crane doesn’t move • load too heavy lighten load
• wheels poorly lubricated or damaged inspect and repair as necessary
• wheels bearings broken or seized inspect and repair as necessary
crane swerves • floor surface loose or unlevel inspect and repair as necessary
• wheels bent or damaged inspect and replace as necessary
boom bounces up and down • load too heavy lighten load
• floor surface loose or unlevel inspect and repair as necessary
• wheels worn or damaged inspect and replace as necessary
unusual noises
high pitched squeak • poor lubrication lubricate entire crane properly
grinding noise • contaminated lubricant at rotation points clean and lubricate rotation points
rattling noise • loose bolts, set screws or other fasteners tighten all bolts and other fasteners
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 12
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3.4 Repairing the Crane
3.4.1 GET FACTORY AUTHORIZATION for all repairs. Unauthorized repairs
will void the warranty, and may lead to damage or failure of the crane.
3.4.2 REPLACE DAMAGED OR POORLY OPERATING PARTS with Thern
repair parts.
3.4.3 REFINISH AREAS where the paint is worn or flaking. A good finish helps
to protect against corrosion and weather damage.
a REMOVE THE FINISH from damaged areas, down to the bare metal.
b CLEAN THE AREA thoroughly.
c REPAINT with a high quality primer and finishing coat.
3.4.4 TO ORDER REPAIR PARTS, contact Thern, Inc. Include the following
information when ordering:
• model number
• serial number (or code number)
• part number
• date purchased, and from whom
• description of what happened, or what is wrong
• your name and return address
3.4.5 THE HYDRAULIC JACK B6017 is a modified Norco 76402A.
aIf you would like to purchase a new jack for the crane, please contact Thern, Inc.
b548 cranes with a serial number of 5012-66448 or higher are equipped with
a Norco bottle jack, P/N B6017. Cranes with an earlier serial number require
the purchase of a B6022 replacement kit.
Important!
• It is your responsibility to de-
termine when to replace parts.
When considering whether to
continue using a part or to replace
it, remember that replacing it
is the best way to avoid further
equipment damage.
• Appoint a qualified person to be
responsible for all repairs to the
equipment.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 13
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4.1 Collapsing the Crane
4.1.1 ADJUST THE BOOM EXTENSION to its shortest length.
4.1.2 LOWER THE BOOM, leaving the release valve untightened.
4.1.3 PUSH THE BOOM tight against the stop which contains the handle spring.
At the same time, tighten the release valve. Then pump on the jack handle
until the unit locks in a collapsed position. Do not force the jack handle.
Forcing the jack handle with the crane collapsed will quickly overload
the pump resulting in failure.
4.1.4 REMOVE THE LEG PINS, remove the legs and slide them into the mast
tubes. Study parts drawing, see page 15.
4.2 Transporting the Crane
4.2.1 PARTIALLY DISASSEMBLE THE CRANE into parts that can be easily
transported.
4.2.2 PACK THE CRANE for transport, using the original packaging materials, if
appropriate.
4.2.3 REASSEMBLE THE CRANE at its new location following the instructions
under Section 1.1 Assembling the Crane.
4.2.4 INSPECT THE CRANE according to Section 3.3 Inspecting the Equipment
under Instructions for Frequent Inspection before installing it for operation.
4.3 Storing the Crane
4.3.1 DISASSEMBLE THE CRANE and store all parts in a cool clean place away
from corrosive chemicals and moisture.
4.3.2 LUBRICATE THE CRANE according to Section 3.2 Lubricating the Crane.
4.3.3 SEAL THE CRANE in plastic with a desiccant to help protect it from rust,
corrosion, and other damage.
4.3.4 REASSEMBLE THE CRANE at its new location following the instructions
under Section 1.1 Assembling the Crane.
4.2.5 INSPECT THE CRANE according to Section 3.3 Inspecting the Equipment
under Instructions for Periodic Inspection before installing it for operation.
Important!
• Keep a record of what you ship,
and when you send it.
Figure 6 – Collapsing the
Crane
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Cranepage 14
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Model 548 Floor Crane
item description part number qty
1 FRAME D1019 1
2 SWIVEL CASTER 3 X 1.25 A2798 2
3 CAPSCREW HEXHD .312-18NC X .750 A3032 8
4 HEX NUT .312-18NC A3250 11
5 WASHER HELSPRLK .312 X .586 X .078 A2925 11
6 WHEEL 4 X 1.5 A2799 2
7 LEG PIN ASSEMBLY A1369 2
8 HEADLESS PIN .625 X 8.618 A1327 2
9 HYDRAULIC JACK B6017 1
10 JACK BASE C4917 1
11 CAPSCREW HEXHD .250-20NC X 1.250 A3050 4
12 JACK BASE CLAMPS A11966 2
13 HELSPRLK WASHER .250 X .489 X .062 A3075 4
14 CLEVIS PIN .500 X 1.516 A1368 1
15 QUICK RELEASE PIN .625 X 2.250 A1366 1
16 SWIVEL WELDMENT C1070 1
17 HEADLESS PIN .625 X 2.282 A1352 1
18 COTTER PIN .156 X 1.000 A3059 5
19 AXLE BOLT .500 X 2.750 A2806 2
20 RIGHT LEG C1065 1
21 LEFT LEG C1064 1
22 BOOM C1067 1
23 BOOM EXTENSION B1126 1
24 HANDLE SPRING 1.095OD X .142WD A1332 1
25 HANDLE SPRING WASHER A1385 1
26 CAPSCREW HEXHD .312-18NC X 1.000 A3028 3
27 BLACK HANDLE GRIP A1043 2
28 HANDLE A1435 1
29 LABEL IMPORTANT ALWAYS INSERT THIS PIN A2188 4
30 THERN LOGO A2178 1
31 LABEL MODEL/CAPACITY B1144 2
32 LABEL WARNING READ BEFORE USING A1302 1
33 LABEL NAMEPLATE SST A1976 1
34 LABEL STOP LIFT AT THIS POINT A1363 1
Model 548 Performance Characteristics 1
load max. hook max. hook
rating reach (at B) height (at C)
boom position 1 1000 lb 31.0 in 66.25 in
boom position 2 800 lb 38.0 in 71.00 in
boom position 3 680 lb 45.0 in 75.75 in
boom position 4 590 lb 52.0 in 80.50 in
Dimensions are for reference only and subject to change without notice.
1 Performance Characterirstics are for standard products referred to in this manual. Non-standard
products may vary from the original design. Contact Thern, Inc. for this information.
Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]

Owner's Manual for Thern Model 548 Floor Crane page 15
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Jamieson Equipment Company | 5314 Palmero Court | Buford, GA 30518 | 800.875.0280 | [email protected]