MBW AR56 User manual

OPERATOR’SSAFETY
AND SERVICE MANUAL
MBW, Inc.
250 Hartford Rd • PO Box 440
Slinger, WI 53086-0440
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.mbw.com
MBW (UK) Ltd.
Units 2 and 3 Cochrane st
Bolton BL3 6BN, England
Phone: [phone]
Fax: [phone]
MBW France S.A.R.L
Z.A. d’Outreville
5 rue Jean Baptiste Néron,
60540 BORNEL, France
Phone: [phone]
Fax: [phone]
L17786 / 5.11.M
©MBW, Inc. 2011
Printed in the USA
AIRAMMER
This manual covers the following serial
numbers
and higher for each model listed:
AR56/AR57 . . . . . . . . . . . . . . . . 570059
RAMMERS

TABLE OFCONTENTS
Safety Information . . . . . . . . . . . . . . . . . . . . . . 1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Safety Decals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . 3
Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Before Starting & Operating . . . . . . . . . . . . . . . . . . . . 4
Motor Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Connecting to Air Compressor . . . . . . . . . . . . . . . . . . 4
Operating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Motor Icing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Stopping Airammer . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Maintenance Schedule . . . . . . . . . . . . . . . . . . . . . . . . 6
Fluid Levels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Checking Percussion System Oil . . . . . . . . . . . . . . . . 6
Changing Percussion System Oil . . . . . . . . . . . . . . . . 6
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Torque Chart. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Service Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Handle Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Motor Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Pinion Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Gearbox Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Gearbox Disassembly . . . . . . . . . . . . . . . . . . . . . . . . 8
Cover Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Crank Gear Removal . . . . . . . . . . . . . . . . . . . . . . . . . 8
Breather Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Lower Unit Disassembly. . . . . . . . . . . . . . . . . . . . . . . 9
Guide Tube and Bellows . . . . . . . . . . . . . . . . . . . . . . 9
Springbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Gearbox Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Crank Gear Assembly . . . . . . . . . . . . . . . . . . . . . . . . 9
Pinion Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Motor Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Cover Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Lower Unit Assembly . . . . . . . . . . . . . . . . . . . . . . . . 10
Gearbox/Lower Unit Assembly. . . . . . . . . . . . . . . . . 10
Handle Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Part Replacement Cycles and Tolerances . . . . . . . . 11
Replacement Parts . . . . . . . . . . . . . . . . . . . . . 13
Gearbox Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Lower Unit Assembly . . . . . . . . . . . . . . . . . . . . . . . . 16
Handle Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Valve Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Warranty- Airammer (AR56/AR57) . . . . . . . . 22

This page intentionally left blank.

- 1 -
SAFETY INFORMATION
Introduction
This Safety Alert Symbol is used to call attention
to items or operations which may be dangerous
to those operating or working with this
equipment. The symbol can be found
throughout this manual and on the unit. Please read these
warnings and cautions, along with all decals, carefully
before attempting to operate the unit. Make sure every
individual who operates or works with this equipment is
familiar with all safety precautions.
WARNING
GENERAL WARNING. Indicates information
important to the proper operation of the
equipment. Failure to observe may result in
damage to the equipment and/or severe bodily
injury or death.
CAUTION
GENERAL CAUTION. Indicates information
important to the proper operation of the
equipment. Failure to observe may result in
damage to the equipment.
Safety Precautions
LETHAL EXHAUST GAS: An internal
combustion engine discharges carbon
monoxide, a poisonous, odorless, invisible
gas. Death or serious illness may result if
inhaled. Operate only in an area with proper
ventilation. NEVER OPERATE IN A
CONFINED AREA!
DANGEROUS FUELS: Use extreme caution
when storing, handling and using fuels, as
they are highly volatile and explosive in vapor
state. Do not add fuel while engine is running.
Stop and cool the engine before adding fuel.
DO NOT SMOKE!
SAFETY GUARDS: It is the owner's
responsibility to ensure that all guards and
shields are in place and in working order.
IGNITION SYSTEMS: Breakerless, magneto,
and battery ignition systems can cause severe
electrical shocks. Avoid contacting these
units or their wiring.
SAFE DRESS: Do not wear loose clothing,
rings, wristwatches, etc. near machinery.
NOISE PROTECTION: Wear OSHA specified
hearing protection devices.
EYE PROTECTION: Wear OSHA specified
eye shields, safety glasses, and sweat bands.
FOOT PROTECTION: Wear OSHA specified
steel-tipped safety shoes.
HEAD PROTECTION: Wear OSHA specified
safety helmets.
DUST PROTECTION: Wear OSHA specified
dust mask or respirator.
OPERATOR: Keep children and bystanders
off and away from the equipment.
REFERENCES: For details on safety rules and regulations
in the United States, contact your local Occupational Safety
and Health Administration (OSHA) office. Equipment
operated in other countries must be operated and serviced
in accordance and compliance with any and all safety
requirements of that country. The publication of these
safety precautions is done for your information. MBW does
not by the publication of these precautions, imply or in any
way represent that these are the sum of all dangers present
near MBW equipment. If you are operating MBW
equipment, it is your responsibility to insure that such
operation is in full accordance with all applicable safety
requirements and codes. All requirements of the United
States Federal Occupational Safety and Health
Administration Act must be met when operated in areas that
are under the jurisdiction of that United States Department.
Safety Decals
Carefully read and follow all safety decals. Keep them in
good condition. If decals become damaged, replace as
required. If repainting the unit, replace all decals. Decals
are available from authorized MBW distributors. Order the
decal set listed on the following page(s).

- 2 -
12203
CAUTION
Read the Operating Instructions
before operating this piece of
equipment.
Keep unauthorized and untrained
people away from this equipment.
ROTATING & MOVING PARTS!
Make sure all guards and safety
devices are in place.
Wear approved hearing protection,
foot protection, eye protection and
head protection.
SHUT OFF the motor before
servicing or cleaning.
Failure to comply could result in
serious bodily injury.
STOP







DANGER
Compressed spring could cause severe injury.
See manual for disassembly instructions.
La resorte comprimida podría causar la
herida severa. Consulte el libro para
ver el desmontaje correcto.
PELIGRO
01326
CAUTION
Machine is top heavy and
could fall if not lifted from
this bar.
17779
AIRAMMER= #120 (54kg)
Safety Decals (Decal Set #12101)
13535
13538
12203
01326
17779
13534



!"$%&''*+-%

'!"$%&''*+-%/!*/6'$%%$
8&:!&!$-!;*%!$6!-"
-<"$!66$'$%%&$>!>;*
%-&*;?">$!$!
&/!$!%'&%-">;@-!;*
@"**!";*"6?">!?"*"+   
"#$%'#
B*!%!&!$-!;*%'
19789 (not in
decal set)

- 3 -
SPECIFICATIONS
Specifications subject to change without notice
AR56 AR57
Operating Weight 123 lbs (56 kg) 125 lbs (57 kg)
Percussion Rate 650 blows/minute 650 blows/minute
Shoe Size 11” x 13” (28 cm x 33cm) 13” x 15” (33 cm x 38 cm)
Travel Speed 60 ft/min (18.3 m/min) 60 ft/min (18.3 m/min
Compaction Area 3300 ft2/hour (307m2/hour) 3900 ft2/hour (362m2/hour)
Air Requirement 75 cfm @ 110 psi 75 cfm @ 110 psi
Operating Speed 4500 rpm 4500 rpm
AR56

- 4 -
OPERATION
Introduction
MBW equipment is intended for use in very severe
applications. The Airammer is powered by a pneumatic
motor and is available with different size tamping shoes.
This parts manual contains only standard parts. Variations
of these parts as well as other special parts are not included.
Contact your local MBW distributor for assistance in
identifying parts not included in this manual.
Before Starting & Operating
• REMEMBER! It is the owner’s responsibility to
communicate information on the safe use and proper
operation of this unit to the operators.
• Review ALL of the Safety Precautions listed on page 1 of
this manual.
• Familiarize yourself with the operation of the machine
and confirm that all controls function properly.
• Know how to STOP the machine in case of an
emergency.
• Make sure hands, feet, and clothing are at a safe
distance from any moving parts.
Motor Lubrication
Oil lubrication must be supplied to the Airammer at all times
during operation. Operating the Airammer without
lubrication will cause damage to the pneumatic motor.
If the supply hose from the compressor to the Airammer is
less than 50’ long, the oiler on the compressor should be
sufficient.
If the supply hose is longer than 50’, a high volume in-line
oiler should be installed near the Airammer. Do not install
the oiler on the Airammer handle. The air lubrication system
should supply 1/2 oz of oil for every 8 hours of operation.
Use suitable air tool oil such as Exxon Spinesstic 10,
Atlantic Richfield Duro 55, Gulf Gulfspin 10, or any other
equivalent.
Connecting to Air Compressor
For proper operation, the Airammer requires a compressed
air supply of at least 75 cfm at 110 psi.
1. Start compressor and check pressure gage to verify
proper operation of the compressor.
2. Connect air hose to compressor outlet and install
safety clips if required.
3. Connect air hose to Airammer coupler and install
safety clips if required.
4. Open compressor valve to pressurize Airammer.
Operating
CAUTION
Always wear safety goggles and hearing protec-
tion when operating Airammer.
1. Squeeze the Airammer actuator handle and check
the Airammer pressure gauge.
2. If the pressure reading is less than 100 psi (indicated
as a red section on some gages), the air pressure at
the source must be increased.
3. On uneven terrain, pushing down on the handle will
aid climbing ability.
CAUTION
Do not bear down (body weight of operator) on
the machine.
4. After three passes, the rammer may have more kick
back. This is an indication that ideal compaction is
being reached.
Motor Icing
If the Airammer is operated for long periods of time or in a
high humidity environment, frost will form on the motor. This
is normal and will not harm the motor. If the motor should
“freeze up” from icing, allow it to thaw before continuing use.
Ensure there is adequate oil supply to the motor.

- 5 -
Stopping Airammer
1. Release Airammer actuator handle.
2. Close compressor valve to release supply pressure
to the Airammer.
3. Squeeze the actuator handle to relieve all residual air
pressure in the hose.
4. Disconnect the air hose from the Airammer.
WARNING
Always stop the motor and disconnect the air
supply before:
Leaving the equipment unattended for any
amount of time.
Before making any repairs or adjustments to the
machine.

- 6 -
MAINTENANCE
WARNING
Always exercise the stopping procedure before
servicing or lubricating the unit.
After servicing the unit, replace and fasten all
guards, shields, and covers to their original
positions before resuming operation.
CAUTION
Always verify fluid levels and check for leaks after
changing fluids.
Do not drain oil onto ground, into open streams,
or down sewage drains.
Maintenance Schedule
1. Change oil in lower unit after first 50 hours of operation, then follow the maintenance schedule.
2. Check all hardware after the first 5 hours of use, then follow the maintenance schedule.
Fluid Levels
Checking Percussion System Oil
Refer to Lower Unit Assembly, page 16.
The rammer percussion system and gearbox are lubricated
by an oil mist which is formed and carried throughout the
rammer by a pumping action in the machine's lower system.
1. Before daily operation, place the rammer on a flat
surface and check the oil level in the glass sight (#12)
on the spring box (#14).
2. If the oil is not visible in the sight gauge, add oil as
required. See Fluid Levels above for recommended
type of oil.
Changing Percussion System Oil
Refer to Lower Unit Assembly, page 16.
1. Tip the rammer backward so the handle is on the
ground.
2. Remove the pipe plug (#19) below the sight glass
(#12) on the back of the spring box (#14).
3. Place an oil pan under the drain hole.
4. Rotate the rammer to drain the oil into the oil pan.
The gearbox may need to be elevated to get all of the
oil to drain.
5. Replace the pipe plug.
6. Lay rammer with valve side down.
7. Remove the pipe plug (#33, page 14) next to the
breather on the top of the gearbox.
8. Fill the system with oil. See Fluid Levels above for
recommended type and quantity of oil.
9. Replace pipe plug in gearbox.
SYSTEM MAINTENANCE EACH USE EVERY 25
HOURS
EVERY 300
HOURS YEARLY
Percussion
System Check oil level XX
Change oil1XX
Hardware Check and tighten as needed2XX
Shockmounts Check for cracks or tears X
SYSTEM FLUID VOLUME RECOMMENDED OIL
Percussion System 12 oz (360 ml) Service SF SAE 10W-30

- 7 -
SERVICE
Assembly and disassembly should be performed by a
service technician who has been factory trained on MBW
equipment. The unit should be clean and free of debris.
Pressure washing before disassembly is recommended.
• Prior to assembly, wash all parts in a suitable cleaner or
solvent.
• Check moving parts for wear and failure. Refer to the
Replacement section in this manual for tolerance and
replacement cycles.
• All shafts and housings should be oiled prior to pressing
bearings. Also, ensure that the bearings are pressed
square and are seated properly.
• All bearings should be replaced when rebuilding any
exciter or gearbox.
• All gaskets and seals should be replaced after any
disassembly.
Torque Chart
Service Tools
General
The disassembly and assembly procedures given on the
next few pages are intended for a complete dismantling of
the rammer. Read the following sections carefully. It is not
necessary to follow the complete disassembly procedure
when only partial disassembly is required. If repairs have to
be made to the Lower Unit only, it is recommended that the
drive unit (engine, gearbox and handle) be removed from
the lower unit. Refer to Remove the three whiz lock screws
(#30) securing the adapter plate (#26) and motor (#22) to
the gearbox (#25)., page 7.
Handle Removal
Refer to Handle Assembly, page 18.
1. Remove the air hose (#3) from the motor (#22, page
14).
2. Remove the four whiz-lock screws (#11) securing the
handle (#7) to the shockmounts (#8).
Motor Removal
NOTE: It is not necessary to remove the handle to take
the motor off the rammer.
Refer to Gearbox Assembly, page 14.
1. Remove the three whiz lock screws (#30) securing
the adapter plate (#26) and motor (#22) to the
gearbox (#25).
Pinion Removal
NOTE: The pinion will be removed from the gearbox
with the airammer motor.
Refer to Gearbox Assembly, page 14.
1. Remove the the three socket screws (#31) to detach
the motor adapter plate (#26) from the motor (#22).
2. Remove the pinion (#27) from the motor (#22) by
unscrewing it using the wrench flats on the pinion.
SIZE GRADE 2 GRADE 5 GRADE 8
1/4-20 49 in•lbs 76 in•lbs 9 ft•lbs
1/4-28 56 in•lbs 87 in•lbs 10 ft•lbs
5/16-18 8 ft•lbs 13 ft•lbs 18 ft•lbs
5/16-24 9 ft•lbs 14 ft•lbs 20 ft•lbs
3/8-16 15 ft•lbs 23 ft•lbs 33 ft•lbs
3/8-24 17 ft•lbs 26 ft•lbs 37 ft•lbs
7/16-14 24 ft•lbs 37 ft•lbs 52 ft•lbs
7/16-20 27 ft•lbs 41 ft•lbs 58 ft•lbs
1/2-13 37 ft•lbs 57 ft•lbs 80 ft•lbs
1/2-20 41 ft•lbs 64 ft•lbs 90 ft•lbs
9/16-12 53 ft•lbs 82 ft•lbs 115 ft•lbs
5/8-11 73 ft•lbs 112 ft•lbs 159 ft•lbs
5/8-18 83 ft•lbs 112 ft•lbs 180 ft•lbs
3/4-16 144 ft•lbs 200 ft•lbs 315 ft•lbs
1-8 188 ft•lbs 483 ft•lbs 682 ft•lbs
1-14 210 ft•lbs 541 ft•lbs 764 ft•lbs
1-1/2-6 652 ft•lbs 1462 ft•lbs 2371 ft•lbs
M 6 3 ft•lbs 4 ft•lbs 7 ft•lbs
M 8 6 ft•lbs 10 ft•lbs 18 ft•lbs
M 10 10 ft•lbs 20 ft•lbs 30 ft•lbs
CONVERSIONS
in•lbs x 0.083 = ft•lbs
ft•lbs x 12 = in•lbs
ft•lbs x 0.1383 = kg•m
ft•lbs x 1.3558 = N•m
Part No. Description
01629 Rubber Test Mat
20260 Springbox Tool
07205 Bellows Installation tool
07552 Blind Hole Bearing Puller Tool

- 8 -
Gearbox Removal
It is necessary to remove the handle and motor to remove
the gearbox.
Refer to Gearbox Assembly, page 14.
1. Remove the four socket head cap screws (#35) and
lockwashers (#21) securing the gearbox (#25) to the
guide tube (#17, page 16).
2. Compress the bellows enough to insert a small
wooden block between the gearbox (#25) and the
guide tube (#17, page 16).
3. Use the wooden block as a pivot point to separate the
gearbox (#25) from the guide tube (#17, page 16) to
expose the piston pin (#17).
4. Hold the gearbox (#25) and tap out the piston pin
(#17) with a hammer and drift pin. See Figure 1.
Gearbox Disassembly
NOTE: It is necessary to remove the gearbox before
disassembly.
Refer to Gearbox Assembly, page 14.
Cover Removal
1. Remove the six flange head screws (#32) securing
the cover (#23) to the gearbox (#25).
2. Install two of the screws from step 1 into the threaded
holes protected by the caps (#7). Turn them in to
back out the cover. If the cover should cock, a pry bar
may be used to bring the cover off straight. See
Figure 2.
3. Remove and discard the o-ring (#9).
Crank Gear Removal
1. Slip a retaining ring pliers through the slot in the
opening in the crank gear (#10) and remove the
retaining ring (#15). See Figure 3..
2. Remove the hex head cap screw (#34) and seal
washer (#16) from the cover.
3. Use a 3/8” (10mm) diameter steel rod to press the
crank gear out of the cover.
4. Remove the retaining ring (#1) from the crank gear.
5. Press the bearing (#4) off the crank gear.
6. Remove the small retaining ring (#14) from the crank
gear.
7. Remove the connecting rod (#8) from the crank gear.
8. Remove the retaining ring (#13) from the connecting
rod.
9. Press the bearing (#5) out of the connecting rod.
Figure 1
3,6721
3,1
:22'
%/2&.

3,927
Figure 2.

Figure 3.
5(7$,1,1*
5,1*

- 9 -
10. Use a blind hole bearing puller to remove the two
needle bearings (#11 and #12) from the cover.
Breather Removal
Refer to Gearbox Assembly, page 14.
1. Remove the socket pipe plug (#29) from the top of the
breather assembly.
2. Remove spring (#19), washer (#28), and valve (#18).
Lower Unit Disassembly
The lower system can be separated from the drive unit
(engine, gearbox, and handle) without going thought the
complete disassembly procedure. If the lower unit has not
been separated, see Gearbox Removal, page 7.
Refer to Lower Unit Assembly, page 16.
Guide Tube and Bellows
1. Drain the oil from the system. Refer to Changing
Percussion System Oil, page 6.
2. Remove the six hex head cap screws (#21) and
lockwashers (#22) securing the spring box (#14) to
the bellows mount (#8) and guide tube (#9).
3. Remove the guide tube, bellows, and bellows
clamps.
4. Remove the retaining ring (#10) from the guide tube.
5. Remove the slide bearings (#5) from the guide tube.
Carefully drive the bearings out from the opposite
end of the tube. Be careful not to scratch or gouge
the inner guide tube walls.
6. Remove the six hex head cap screws (#23) and
lockwashers (#24) securing the shoe (#13). Remove
the shoe.
Springbox
WARNING
Working with compressed springs. Failure to
follow the next set of steps very carefully could
result in serious injury or death.
1. Flip the springbox assembly upside down.
2. Insert the springbox tool (MBW #20260) rods into the
springbox assembly as shown in Figure 4.
3. Make sure the rods are 180° apart.
4. Place the washers over the rods and run the nuts
down so the washers are snug against the cover (#3).
5. Remove the flat head socket screws (#20) holding
the cover to the springbox.
6. While holding the bottom of the rods from turning,
slowly and evenly back off the nuts on the cover side.
7. After the tension is removed from the cover, the
springbox tools and the cover can be removed.
8. Remove the o-ring (#6) from the cover and discard.
9. The lower springs (#1 and #2) can be removed from
the springbox (#21).
10. Place a drift pin or steel rod through the piston hole in
the ram head (#4). Use this to hold the ram head
from turning while removing the hex nut (#7). Discard
the hex nut
11. Remove the washers spring separtor (#17), and
upper springs (#1 and #2).
Gearbox Assembly
Make sure all bearings are pressed on square and are
seated properly. All shafts and housings should be lightly
oiled prior to pressing any bearings.
Refer to Gearbox Assembly, page 14.
Crank Gear Assembly
1. Press the bearing (#5) into the connecting rod (#8)
and secure with an internal retaining ring (#13).
2. Press the connecting rod assembly onto the crank
gear (#10) and secure with an external retaining ring
(#14).
3. Slip a retaining ring onto the crank gear.
4. Press a bearing (#4) onto the crank gear. Secure
with a retaining ring (#1).
5. Press the needle bearings (#11 and #12) into the
cover (#23). The bearing must be pressed in with
the numbers and letters facing outward.
Figure 4.
635,1*%2;
722/6



- 10 -
6. Press the crank gear into the cover. Place a snap
ring pliers through the slot in the crank gear and
secure the retaining ring (#15).
Pinion Assembly
Refer to Gearbox Assembly, page 14.
1. Use the wrench flats on the pinion (#27) to thread the
it onto the motor (#22).
2. Reattach the motor adapter plate (#26) to the motor
(#22) using three socket screws (#31).
Motor Assembly
Refer to Gearbox Assembly, page 14.
1. Install the motor (#22) and adapter plate (#26) to the
gearbox (#25) using three whiz-lock screws (#30).
Cover Assembly
1. Apply a light coat of oil to the o-ring (#9).
2. Tip the cover to feed the connecting rod into the
gearbox.
3. Press the cover onto the gearbox.
4. Secure with six flange head screws (#32).
5. Put two plastic plugs (#7) into the threaded holes on
the cover.
6. Assemble the seal washer (#16) and hex head cap
screw (#34). Replace the seal washer if it is
damaged.
Lower Unit Assembly
Refer to Lower Unit Assembly, page 16.
Note: Compare springs before installing. If not all the
same height, replace all springs. Never replace
only one.
1. Place the ram (#4) into the springbox (#14) and turn
the assembly upside down.
2. Insert an inner and outer spring into the springbox.
3. Wrap the slide bearing (#18) around the spring
separator and insert into spring box..
4. Install a new nyloc hex nut (#7) onto the ram.
5. Place a drift pin through the hole in the ram head and
tighten the hex nut to 100ft lbs (135 Nm).
6. Place the lower springs (#1 and #2) into the
springbox.
7. Lightly grease the groove in the cover (#3) and install
a new o-ring (#6).
8. Place the cover over the springs and align the holes.
WARNING
Working with compressed springs. Failure to
follow the next set of steps very carefully could
result in serious injury or death.
9. Insert the rods from the springbox tool through the
springbox and up thought the cover. Make sure the
rods are 180° apart.
10. Place the washers and hex nuts on the rods.
11. Slowly and evenly draw the cover down onto the
springbox by alternately tightening each rod.
WARNING
Keep the cover level with the springbox during
assembly.
12. Secure the cover to the springbox with three flat head
screws (#20). Torque to 8 ft lbs (11 Nm).
13. The decal on the bottom of the springbox should be
clean and easy to read. If it is not, the old decal
should be completely removed and replaced..
14. Install a new set of slide bearings (#5) into the guide
tube (#9) and secure with the retaining ring (#10).
15. Slide the bellows and guide tube over the springbox
and align with the words “ground pounder” to the
front.
16. Secure the bellows to the guide tube and bellows
mount with twelve hex head cap screws (#21) and
lockwashers (#22). Do not tighten.
17. Assembly the shoe with six bolts (#23) and
lockwashers (#24). Torque to 50 ft lbs (67 Nm).
18. Now align shoe and guide tube and tighten hex head
cap screws (#21) and lockwashers (#22).
Gearbox/Lower Unit Assembly
Refer to Gearbox Assembly, page 14.
1. Place a new gasket (#20) onto the guide tube (#9,
page 16).
2. Push the guide tube down and place the piston pin
(#17) into the ram head (#4, page 16). Let the pin
stick out so it does not block the slot in the top of the
ram head. The pin will also hold the guide tube down.
3. Place the gearbox over the lower assembly and line
up the connecting rod assembly (#8) with the piston
pin.
4. Push the piston pin through the connecting rod
bushing. Keep pushing the piston pin in until the
guide tube slides past and covers the pin.

- 11 -
5. Secure the gearbox to the guide tube using four
socket head cap screws (#35) and high collar
lockwashers (#21). Apply 243 Loctite.
Handle Assembly
Refer to Handle Assembly, page 18.
1. Secure the handle (#7) to the shockmounts (#8)
using four whiz-lock screws (#11).
2. Reattach the hose (#3) to the motor (#22, page 14)
and secure with two new clamps (#9).
Part Replacement Cycles and Tolerances
Bearings Replace anytime a bearing is rough, binding, discolored or removed from housing or
shaft.
Bearing, Bronze, Springbox Replace if there are wear marks or the ID is greater than 1.145 in (29mm).
Bellows Replace if the bellows are worn or cracked to the point of leaking.
Bushing, Bronze, Crankshaft Replace if there are wear marks or the ID is greater than 0.630 in (16mm).
Clutch Replace shoes and spring if they show signs of heat damage or if the clutch does not
disengage below 2000 rpm.
Guide Bushings Replace if a 0.025 in (0.635mm) feeler gage can be slide between the springbox and
the guide bushings.
Hardware Replace any worn or damaged hardware as needed. Replacement hardware should
be grade 5 and zinc plated unless otherwise specified.
O-rings and Seals Replace at every tear down. Use MBW O-ring and seal kit #06472.
Motor Components Refer to the motor manufacturer’s Owner’s Manual.
Piston, Plastic, Springbox Replace if a 0.025 in (0.635mm) feeler gage can be slide between the springbox and
the piston.
Piston Pin Replace if the OD is less than 0.620 in (15.75mm).
Piston Washers Replace if dished.
Ram Replace if shaft is less than 1.120 in (28.4mm).
Safety Decals Replace if they become damaged or illegible.
Seals & Gaskets Replace if a leak is detected and at every overhaul or tear down.

- 12 -
This page intentionally left blank.

- 13 -
MBW, Inc.
250 Hartford Rd • PO Box 440
Slinger, WI 53086-0440
Phone: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.mbw.com
MBW (UK) Ltd.
Unit 6, Bradley Fold Trading Estate
Radcliffe Moor Road
Bolton BL2 6RT, England
Phone: [phone]
Fax: [phone]
Contact Information
MBW France S.A.R.L
Z.A. d’Outreville
11 rue Jean Baptiste Néron,
60540 BORNEL, France
Phone: [phone]
Fax: [phone]
REPLACEMENT PARTS
The warranty is stated in this book on page 18. Failure to
return the Warranty Registration Card renders the warranty
null and void.
MBW has established a network of reputable distributors/
dealers with trained mechanics and full facilities for
maintenance and rebuilding, and to carry an adequate parts
stock in all areas of the country. Their sales engineers are
available for professional consultation. If you cannot locate
an MBW distributor in your area, contact MBW or one of our
Sales Branches listed below.
When ordering replacement parts, be sure to have the
following information available:
• Model and Serial Number of machine when ordering
MBW parts
• Model and Serial Number of engine when ordering
engine parts
• Part Number, Description, and Quantity
• Company Name, Address, Zip Code, and Purchase
Order Number
• Preferred method of shipping
REMEMBER - You own the best! If repairs are needed,
use only MBW parts purchased from authorized
MBW distributors.
The unit’s serial number can be found in the following
locations:
• The serial number decal is located on the back of the
gearbox.
• The serial number is stamped on the back of the gearbox
next to the decal.
Write Model Number here
Write Serial Number here
'(&$/
67$03('

- 14 -


















 















Gearbox Assembly

- 15 -
ITEM PART NO. DESCRIPTION QTY
1. 01001 RETAINING RING, EXT. 5100-137 1
2. 01002 SEAL, OIL 1
3. 01072 FILTER, FELT 1
4. 01103 BEARING, BALL 1
5. 01105 BEARING, BALL 1
6. 01191 RETAINING RING, INTERNAL 1
7. 05559 PLUG 2
8. 06161 ROD ASM, CONNECTING 1
9. 06238 O-RING, 6.23 ID X 0.139 DIA 1
10. 06240 GEAR 1
11. 06259 BEARING, NEEDLE 1
12. 06260 BEARING, NEEDLE 1
13. 06264 RETAINING RING, INT .N5000-187 1
14. 06265 RETAINING RING, EXT .5100-78 1
15. 06266 RETAINING RING, INT .N50000-281 1
16. 06275 WASHER, SEAL 1
17. 06304 PIN, PISTON 1
18. 06413 VALVE 1
19. 06423 SPRING, COMP. .420 OD 1
20. 06925 GASKET 1
21. 08504 LOCKWASHER, 1/2 HIGH COLLAR 4
22. 12189 MOTOR, PNEUMATIC TCS 1
23. 15768 COVER, GEARCASE (MACH.) 1
24. 19708 FITTING, ST, 1/2 NPT X 3/4 HOSE 1
25. 19754 HOUSING, GEARBOX, AR56/57 1
26. 19779 MOTOR ADAPTER, AIRAMMER 1
27. 19782 PINION, GROUND, AR56/57 1
28. F01PW WASHER, 5/32 X 3/8 X 18 GA ZP 1
29. F0418SPP SOCKET PIPE PLUG, 1/4-18 1
30. F042008FWS FWLS, 1/4-20 X 1 ZP 3
31. F042014FSS FSS, 1/4-20 X 1-3/4 3
32. F051808FWS FWLS, 5/16-18 X 1 ZP 6
33. F0618SPP PLUG, PIPE 3/8-18 1
34. F081305HCS HHCS, 1/2-13 X 5/8 GR5 ZP 1
35. F081312SCS SCS, 1/2-13 X 1-1/2 4
KITS
19392 KIT, AIRAMMER MOTOR, REBUILD

- 16 -






























Lower Unit Assembly

- 17 -
ITEM PART NO. DESCRIPTION QTY
1. 03167 SPRING, COMPRESSION, 2.188” OD 2
2. 03168 SPRING, COMPRESSION, 2.875” OD 2
3. 06173 COVER 1
4. 06174 RAM 1
5. 06180 BEARING, SLIDE 2
6. 06237 O-RING, 4.33” ID 1
7. 06257 NUT, HEX 7/8”-14 NYLOC 1
8. 07154 RING, CLAMPING 2
9. 07163 TUBE, GUIDE (INCLUDES ITEMS 5 AND 10) 1
10. 07735 RETAINING RING, EXTERNAL 1
11. 11694 BELLOWS 1
12. 18276 PLUG, OIL LEVEL 1
13. 07507 SHOE, 11” X 13” (56AC ONLY) 1
03172 SHOE, 13” X 15” (57AC ONLY) 1
19728 SHOE, 11” IRON (56IC ONLY) 1
14. 19763 SPRING BOX 1
15. 19889 SLIDE BEARING, FORMED, 480 1
16. 19890 RETAINING RING, INTERNAL 1
17. 19891 SPRING SEPARATOR, 482 1
18. 19893 SLIDE BEARING, FORMED, 482 1
19. F0227SPP SOCKET PIPE PLUG, 1/8”-27 1
20. F042005FSS FLAT HEAD SCREW, 1/4”-20 X 5/8” ZP 3
21. F042008HCS HEX HEAD SCREW, 1/4”-20 X 1” ZP 12
22. F04LW LOCKWASHER, 1/4” ZP 12
23. F071412HCS HHCS, 7/16-14 X 1-1/2 GR5 ZP 6
24. F07LW LOCKWASHER, 7/16” ZP 6