Idex Gast 2AM Series Manual

1
LUBRICATED AIR MOTORS
OPERATION & MAINTENANCE MANUAL
Product Use Criteria:
• Operate at temperature up to 250ºF (121ºC).
• Protect unit from dirt and moisture.
• Use ONLY compressed air to drive motor.
• Air lines connected to motor should be the same size or
the next size larger than the intake port for efficient
output and speed control.
• Protect all surrounding items from exhaust air.
• Bearings are grease packed.
• Use Gast #AD220 or a detergent SAE#10 automotive
engine oil for lubricating.
Model 2AM Shown Model 4AM Shown
IMPORTANT: PLEASE READ THIS MANUAL AND SAVE FOR FUTURE REFERENCE.
Thank you for purchasing this Gast product. It is manufactured to the highest standards
using quality materials. Please follow all recommended maintenance, operational
and safety instructions and you will receive years of trouble free service.
General information
• Clearances: Model Total End Clearance (in/mm) Top Clearance (in/mm)
1AM/1 UP 0.0020/0.0508 0.0015/0.0381
2AM 0.0025/0.0635 0.0015/0.0381
2AM * 0.0025/0.0635 0.0025/0.0635
4AM 0.0035/0.0889 0.0015/0.0381
4AM * 0.0035/0.0889 0.0025/0.0635
6AM 0.0035/0.0889 0.0015/0.0381
8AM 0.0048/0.1219 0.0015/0.0381
16AM 0.0060/0.1524 0.0015/0.0381
* Models with the last three digits greater than 500 (ie 2AM XXX-501)
• Vane Life: Depends upon speed, operating pressure and motor maintenance.
• Operating Pressure: 100 psi or below (7 bar)
www.gastmfg.com
ISO 9001 & 14001 CERTIFIED
®Registered Trademark/™Trademark of Gast Manufacturing Inc., Copyright ©2001 Gast Manufacturing Inc. All Rights Reserved.
PART NO. 45-200 D170PL (Rev. K)
Model 6AM Shown Model 16AM Shown

2
Your safety and the safety of others
is extremely important.
We have provided many important safety messages
in this manual and on your product. Always read
and obey all safety messages.
This is the safety alert symbol. This symbol
alerts you to hazards that can kill or hurt you and
others. The safety alert symbol and the words
“DANGER” and “WARNING” will precede all safety
messages. These words mean:
You will be killed or seriously injured if you don’t
follow instructions.
You can be killed or seriously injured if you don’t
follow instructions.
All safety messages will identify the hazard, tell you
how to reduce the chance of injury, and tell you
what can happen if the safety instructions are not
followed.
Correct installation is your responsibility. Make
sure you have the proper installation conditions and that
the specified installation clearances are available.
INSTALLATION
Accessories
A muffler is shipped with the air motor (except 16AM)
but is not installed. Consult your Gast representative
WARNING
DANGER
Connection
Check the direction of the motor airflow. A single
rotation motor will operate properly only in one direction.
Install a filter in the air line before the connection to the
motor. Connect lines to motor in the proper direction.
A reversible motor will work equally well in both
directions. Connecting a 4-way valve with piping to
both air ports of the motor will make reversing possible.
Do not add any thrust to the end or side of the shaft
when making connections. Do not use a hammer
on the shaft or connections.
Mounting
This product can be installed in any orientation. Mount
the motor to a solid base plate that is mounted to a
stable, rigid operating surface. Install a pressure
regulator or simple shut-off valve to control motor.
Injury Hazard
Install proper guards as needed.
Failure to follow this instruction can result in
burns or other serious injury.
WARNING
for additional filter recommendations. Install a moisture
trap and filter in the air line ahead of the motor. For the
most efficient output and control of speed, use air lines
that are the same size or the next pipe size larger than
the motor intake port.
An automatic air line lubricator should be installed 18”
or as close as possible in the air line just ahead of the
motor. Adjust the lubricator to feed one drop of oil for
every 50-75 CFM of air moving through the motor. Air
consumption at various speeds and pressures are
available from your local Gast representative or the
factory.
It is your responsibility to operate this product at
recommended speeds, loads and room ambient
temperatures. Do not run the motor at high speeds
with no load. This will result in excessive internal
heat that may cause motor damage.
The starting torque is less than the running torque. The
starting torque will vary depending upon the position of
the vanes when stopped in relation to the air intake
port.
Use a pressure regulator and/or simple shut-off valve to
regulate the motor’s speed and torque. This will provide
the required power and will conserve air.
OPERATION
Injury Hazard
Air stream from product may contain solid or liquid
material that can result in eye or skin damage.
Do Not use combustible gases to drive this motor.
Wear hearing protection. Sound level from motor
may exceed 85db(A).
Failure to follow these instructions can result in
burns, eye injury or other serious injury.
WARNING
MAINTENANCE
Injury Hazard
Disconnect air supply and vent all air lines.
Wear eye protection when flushing this product.
Air stream from product may contain solid or liquid
material that can result in eye or skin damage.
Flush this product in a well ventilated area.
Do Not use kerosene or other combustible solvents
to flush this product.
Failure to follow these instructions can result in
burns, eye injury or other serious injury.
WARNING
It is your responsibility to regularly inspect and
make necessary repairs to this product in order to
maintain proper operation.

3
Check intake and exhaust filters after first 500 hours of
operation. Clean filters and determine how frequently
filters should be checked during future operation. This
one procedure will help assure the product’s
performance and service life.
Flushing
Flushing this product to remove excessive dirt, foreign
particles, moisture or oil that occurs in the operating
environment will help to maintain proper vane
performance. Flush the motor if it is operating slowly or
inefficiently.
Use only Gast #AH255B Flushing Solvent. DO NOT
use kerosene or ANY other combustible solvents to
flush this product.
Lubrication
Use Gast #AD220 or a detergent SAE #10 automotive
engine oil for lubricating. Lubricating is necessary to
prevent rust on all moving parts. Excessive moisture in
the air line may cause rust or ice to form in the muffler
when air expands as it passes through the motor.
Install a moisture separator in the air line and an after
cooler between compressor and air receiver to help
prevent moisture problems.
Manual Lubrication
Shut the air motor down and oil after every 8 hours of
operation. Add 10-20 drops of oil to the air motor intake
port.
Automatic Lubrication
Adjust inline oiler to feed 1 drop of oil per minute for
high speed or continuous duty usage. Do Not overfeed
oil or exhaust air may become contaminated.
1. Disconnect air line and muffler.
2. Add flushing solvent directly into motor. If using
liquid solvent, pour several tablespoons directly
into the intake port. If using Gast #AH255B, spray
solvent for 5-10 seconds into intake port.
3. Rotate the shaft by hand in both directions for a
few minutes.
4. You must wear eye protection for this step.
Cover exhaust with a cloth and reconnect the air
line. Slowly apply pressure until there is no trace
of solvent in the exhaust air.
5. Listen for changes in the sound of the motor. If
motor sounds smooth, you are finished. If motor
does not sound like it is running smoothly,
installing a service kit will be required.
(See “Service Kit Installation”).
Check that all external accessories such as relief
valves or gauges are attached and are not damaged
before operating product.
Shutdown
It is your responsibility to follow proper shutdown
procedures to prevent product damage.
1. Turn off air intake supply.
2. Disconnect plumbing.
3. Remove air motor from connected machinery.
4. Wear eye protection. Keep away from air
stream.
Use clean, dry air to remove condensation.
5. Lubricate motor with a small amount of oil in
chamber. Rotate shaft by hand several times.
6. Plug or cap each port.
7. Coat output shaft with oil or grease.
8. Store motor in a dry environment.
Gast will NOT guarantee field-rebuilt product
performance. For performance guarantee, the
product must be returned to a Gast authorized
service facility.
SERVICE KIT INSTALLATION
Service kit contents vary. Most contain vanes, end cap
gasket, body gasket, bearings and a muffler element or
felt.
Minor Rebuild:
1. Remove the end cap.
2. Remove dead end plate bolts.
3. Remove dead end plate. (Use factory issued tool,
do not use screwdriver to remove the end plate.
4. Remove the dowel pins from the body and push
back into end plate until flush or just below the
machined surface of the end plate.
5. Remove vanes.
6. Clean parts. Check for scoring on the end plate
and rotor assembly. If scoring exists, send unit to
a Gast authorized service facility.
7. Lubricated models only: Lightly oil and reinstall
vanes.
8. Place the proper end plate gasket on the end
plate. If the original is damaged, replace with a
new one supplied in the Service Kit.
9. Place the dead end plate on the body.
10. Press the bearing onto the shaft using a factory
supplied bearing pusher.
11. Tap dowel pins into body and install end plate
bolts. Tighten bolts to 75-100 in-lbs.
12. Set end clearance as required by model:
1AM-4AM and NL22-NL52 models - use the
bearing taper from kit to lightly tap on inner race of
the dead end bearing to free up and center the
rotor in the body.
6AM-8AM models - lightly strike the drive end
shaft with a soft hammer to push the rotor away
from the drive end plate. The rotor must NOT rub
on either end plate.
13. Reattach end cap.
14. If the air motor is lubricated, apply a few drops
of Gast #AD220 lubricant into ports. Rotate shaft
by hand for a few rotations.
Major Rebuild:
1. Remove the end cap.
2. Remove dead end plate bolts.
Major and Minor Rebuilds
Tool kits which include a more in-depth rebuild
manual are available through your Gast distributor.
These kits include the tools required to remove and
reassemble end plates, bearings and shaft seals, and to
set the proper end clearance. The rebuild manual also
includes step by step instructions, including illustrations,
to help achieve a successful rebuild. Gast
Manufacturing, Inc. highly recommends using the air
motor rebuild manual and tool kit when attempting a
minor or major rebuild to your Gast air motor.

4
3. Remove dead end plate. (Use factory issued tool,
do not use screwdriver to remove the end plate.)
4. Remove the dowel pins from the body and push
back into end plate until flush or just below the
machined surface of the dead end plate.
5. Remove rotor using an arbor press.
6. Remove vanes and ejection mechanism if
reversible. (Ejection mechanisms may consist of
vane springs, pins, caps or cam rings.)
7. Remove shaft seal and bearings from drive end
plate and bearing from dead end plate. (Use
factory issued tool.)
8. Do Not remove drive end plate bolts or drive end
plate.
9. Clean parts. Check for scoring on the end plates
and rotor assembly. If scoring exists, send unit to
a Gast authorized service facility.
10. For reversible models only:
1AM and 1UP models - place a new cam ring
between the rotor and the drive end plate.
2AM and 4AM models - place springs and caps
in rotor.
6AM, 8AM and 16AM models - install push pins.
11. Place the drive shaft of the rotor assembly through
the drive end plate. Press the drive bearing onto
the drive shaft using a factory supplied bearing
pusher.
12. Using the bearing taper from the Tool Kit, lightly
tap on inner race of the drive end bearing to snug
up rotor to drive end plate.
13. Install new vanes as required by model:
All single rotation units - the angle cuts on the
vane face to center of the rotor.
Reversible units 2AM and 4AM - the notch on
vane faces to center of the rotor.
6AM, 8AM and 16AM models - install the vane
spring lip into the notch at one end of the vane
and place in rotor vane slot with spring facing
pushpin.
14. Place the proper end plate gasket on the body of
dead end. If the original is damaged, replace
with a new one supplied in the service kit.
If your air motor uses O-rings, place the new
O-rings in the body groove. Some models do not
use end plate gaskets or O-rings.
15. Place the dead end plate on the body.
16. Install the dead end bearing and press into place
with bearing pusher tool from tool kit.
17. Install the dowel pins.
18. Fully tighten the remaining bolts to 75-100 in-lbs.
19. Set end clearance as required by model:
1AM-4AM and NL22-NL52 models - use the
bearing taper from the Tool Kit and lightly tap on
the inner race of the dead end bearing to free up
and center the rotor in the body.
6AM-8AM models - lightly strike the drive end
shaft with a soft hammer to push the rotor away
from the drive end plate. The rotor must NOT rub
on either end plate.
20. Apply a small amount of grease to bearing seal
and install the drive end bearing seal by pressing
flush with bearing pushing tool from Tool Kit.
21. Reattach end cap.
22. If the air motor is lubricated, apply a few drops
of Gast #AD220 lubricant into ports and rotate
shaft by hand for a few rotations.

5
REF# DESCRIPTION QTY 1AM-NCC-12 1AM-NCW-14 1AM-NRV-39A 1AM-NRV-56 1AM-NRV-60 1AM-NRV-63A
1 ∆SEAL 1 AC190A AC190A AC190A AC190A AC190A AC190A
2 ∆BEARING 2 AG549 AG549 AG549 AG549 AG549 AG549
3 DOWEL PIN 4 D324A D324A D324A D324A D324A D324A
4 DRIVE END PLATE 1 AC537 AC539 AC520 AC520D AC520D AC520
5 ∆∆ SHIMS 2 AC527B AC527B AC527B AC527B AC527B AC527B
6 BODY 1 AC521 AC521 AC191 AC191 AC191 AC191
7 CAM RING 2 AC195 AC195 AC195 AC195
8 ROTOR ASSEMBLY 1 AC524 AC536 AC193 AC187 AC607 AC193B
9 ∆VANE 4 AC205A AC205A AC259A AC259A
8 AC259A AC259A
10 DEAD END PLATE 1 AC538 AC540 AC192 AC192 AC192 AC192
11 ∆END CAP GASKET 1 AC229 AC229 AC229 AC229 AC229 AC229
12 DEAD END CAP 1 AC228A AC228A AC228A AC228A AC228A AC228A
*** ∆MUFFLER 1 AF350 AF350 AF350 AF350 AF350 AF350
*** FOAM 1 AG896 AG896 AG896 AG896 AG896 AG896
*** SERVICE KIT 1 K200 K200 K201 K201 K278 K278
*** Item not shown.
∆Denotes parts included in the Service Kit.
∆∆ Parts used on models manufactured prior to 1998.
Parts listed are for stock models. For specific OEM models, please consult the factory.
When corresponding about or ordering parts, please give complete model and serial numbers.
Exploded views are shown for
reference only. Units may vary
depending upon specific model.
1AM SERIES
1UP SERIES
REF# DESCRIPTION QTY 1UP-NCC-1A 1UP-NCW-2A 1UP-NRV-3A 1UP-NRV-4 1UP-NRV-10 1UP-NRV-11
1 ∆SEAL 1 AC190A AC190A AC190A AC190A AC190A AC190A
2 ∆BEARING 2 AG549 AG549 AG549 AG549 AG549 AG549
3 DOWEL PIN 4 D324A D324A D324A D324A D324A D324A
4 DRIVE END PLATE 1 AC616 AC520B AC520 AC520D AC520 AC520D
5 ∆∆ SHIMS 2 AC527B AC527B AC527B AC527B AC527B AC527B
6 BODY 1 AE899 AE899 AE898 AE898 AE898 AE898
7 CAM RING 2 AC195 AC195 AC195 AC195
8 ROTOR ASSEMBLY 1 AE896 AE895 AE897 AF746 AE319 AE333
9 ∆VANE 4 AE893 AE893 AE894 AE894
8 AE894 AE894
10 DEAD END PLATE 1 AC617 AC192A AC192 AC192 AC192 AC192
11 ∆END CAP GASKET 1 AC229 AC229 AC229 AC229 AC229 AC229
12 DEAD END CAP 1 AC228A AC228A AC228A AC228A AC228A AC228A
*** ∆MUFFLER 1 AF350 AF350 AF350 AF350 AF350 AF350
*** FOAM 1 AG896 AG896 AG896 AG896 AG896 AG896
*** SERVICE KIT 1 K285 K285 K286 K286 K298 K298
EXPLODED PRODUCT VIEW, PARTS & ORDERING INFORMATION

6
*** Item not shown.
** #AL484 (5A) O-ring replaces shim on some models.
∆Denotes parts included in the Service Kit.
Parts listed are for stock models. For specific OEM models, please consult the factory.
When corresponding or ordering parts, please give complete model and serial numbers.
EXPLODED PRODUCT VIEW, PARTS & ORDERING INFORMATION
2AM SERIES
REF# DESCRIPTION QTY 2AM-FCC-1 2AM-NCW-7A 2AM-FCW-13 2AM-NCC-16 2AM-NCC-43A 2AM-ACC-88
METRIC
1 ∆SHAFT SEAL 1 AA466B AA466B AA466B AA466B B2328 B2328
2 ∆DRIVE END BEARING 1 AA299J AA299J AA299J AA299J AB519 AB519
2A ∆DEAD END BEARING 1 AA299J AA299J AA299J AA299J AA299J AA299J
3 DOWEL PIN 4 AB162 AB162 AB162 AB162 AB162C AB162C
4 DRIVE END PLATE 1 AC720 AC726 AC722 AC724 AG708 AK425A
5 ∆** SHIMS 2 B330 B330 B330 B330 B330 B330
6 ROTOR ASSEMBLY 1 AA470A AA489A AA489A AA470A AM449A AM449B
7 ∆VANE 4 AA13B AA13B AA13B AA13B AA13B AA13B
8 BODY 1 AA477 AA467 AA477 AA467 AA467 AA467F
9 DEAD END PLATE 1 AC721 AC723 AC723 AC721 AC721 AB622N
10 ∆END CAP GASKET 1 AA46 AA46 AA46 AA46 AA46 AA46
11 END CAP 1 AM307D AM307D AM307D AM307D AM307D AM307D
12 MUFFLER ASSEMBLY 1 AC980 AC980 AC980 AC980 AC980 AC980
13 MUFFLER FELT 1 AC983 AC983 AC983 AC983 AC983 AC983
*** SERVICE KIT 1 K202 K202 K202 K202 K203A K203A
Exploded views are shown for
reference only. Units may vary
depending upon specific model.

7
REF# DESCRIPTION QTY 4AM-FRV-13C 4AM-NRV-22B 4AM-FRV-24 4AM-NRV-50C 4AM-NRV-54A 4AM-NRV-70C 4AM-ARV-119 4AM-ARV-120
METRIC METRIC
1 ∆SHAFT SEAL 1 AA466B AA466B AA466B (2) B2328 AA466B B2328 B2328 B2328
2 ∆DRIVE END BEARING 1 AA299J AA299J AA299J AB519 AA299J AB519 AB519 AB519
2A ∆DEAD END BEARING 1 AA299J AA299J AA299J AA299J AA299J AA299J AA299J AA299J
3 DRIVE END PLATE 1 AC727 AC665 AC727 AG707 AC665` AG707 AK425A AK425A
4 ROTOR ASSEMBLY 1 AB617 AB617 AM426 AM455A AM411 AM319A AM455C AM455B
5 ∆VANE 4 AB876 AB876 AB876 AB876 AB876
8 AB876 AB876 AB876
6 ∆PUSH PINS 4 AM467 AM467 AM467 AM467 AM467
8 AM467 AM467 AM467
7 ∆VANE SPRING 2 AM466 AM466 AM466 AM466 AM466
4 AM466 AM466 AM466
8 BODY 1 AM425 AM410 AM425 AM410 AM410 AM410 AM410M AM410M
9 ∆** SHIMS 2 B330 B330 B330 B330 B330 B330 B330 B330
10 DEAD END PLATE 1 AC728 AC728 AC727 AC728 AC728 AC728 AB622M AB622M
11 ∆END CAP GASKET 1 AA46 AA46 AA46 AA46 AA46 AA46 AA46
12 DEAD END CAP 1 AM307D AM307D AM307D AM307D AM307D AM307D AM307D
13 MUFFLER ASSEMBLY 1 AC980 AC980 AC980 AC980 AC980 AC980 AC980 AC980
14 ∆MUFFLER FELT 1 AC983 AC983 AC983 AC983 AC983 AC983 AC983 AC983
*** SERVICE KIT 1 K205 K205 K205G K206A K279 K280A K206C K206B
EXPLODED PRODUCT VIEWS, PARTS & ORDERING INFORMATION
*** Item not shown.
** #AL484 (9A) O-ring replaces shims on some models.
∆Denotes parts included in the Service Kit.
Parts listed are for stock models. For specific OEM models, please consult
the factory. When corresponding or ordering parts, please give complete
model and serial numbers.
4AM SERIES
Exploded views are shown for
reference only. Units may vary
depending upon specific model.
REF# DESCRIPTION QTY 4AM-RV-75
1 GEAR STD. 1 AA294
2 ∆BEARING 2 AA299J
3 PIN 1 AA297
4 ROTOR 1 AA293
5 ∆VANE 4 AB876
6 ∆SPRING PIN 4 AM467
7 ∆SPRINGS 2 AM466
8 BODY 1 AM410
9 ∆SHIMS 2 B330
10 DEAD END PLATE 1 AC728
11 ∆END CAP GASKET 1 AA46
12 END CAP 1 AM307D
13 DRIVE END PLATE 1 AA424
14 SEAL 1 AA466B
15 DOWEL PINS 4 AB162
16 1/4-28 x .50 PFHMS 6 BB631
17 1/4-28 x .625 SHCS 6 BB634
*** SERVICE KIT 1 K205
4AM SERIES

8
EXPLODED PRODUCT VIEW, PARTS & ORDERING INFORMATION
*** Item not shown.
∆Denotes parts included in the Service Kit.
Parts listed are for stock models. For specific OEM models, please consult the factory.
When corresponding or ordering parts, please give complete model and serial numbers.
Exploded views are shown for
reference only. Units may vary
depending upon specific model.
REF# DESCRIPTION QTY 6AM-FRV-5A 6AM-NRV-7A 6AM-NRV-22A 6AM-FRV-23A 6AM-ARV-54 6AM-ARV-55 6AM-NRV-11A
NEMA
1 DRIVE END CAP 1 AD642A AD642A AD642A AD642A AC988 AC988 AD642A
2 ∆SHAFT SEAL 1 AC849 AC849 AC849 AC849 AK423 AK423 AC849
3 ∆O-RING 1 AD649 AD649 AD649 AD649 AC989 AC989 AD649
4 ∆DRIVE END BEARING 1 AD638A AD638A AD638A AD638A AC894B AC894B AD638A
5 DOWEL PIN 4 AB162 AB162 AB162C AB162 AB162C AB162C AB162C
6 DRIVE END PLATE 1 AD651 AD666 AD667 AD651 AK424 AK424 AD667
7 ∆BODY GASKET 2 AD641 AD641 AD641 AD641 AD641 AD641 AD641
8 BODY 1 AD650A AD665 AD665 AD650A AD665D AD665D AD665
9 KEY 1 AB136 AB136 AB136 AB136 AK422 AK422 AB136
10 ROTOR ASSEMBLY 1 AD652 AD652 AC398 AC779 AD648E AD648D AD648
11 ∆PUSH PIN 2 AD655A AD655A AD655A AD655A
4 AD655A AD655A AD655A
12 ∆VANE SPRING 4 AD692 AD692 AD692 AD692
8 AD692 AD692 AD692
13 ∆VANE 4 AD691 AD691 AD691 AD691
8 AD691 AD691 AD691
14 DEAD END PLATE 1 AD651 AD651 AD651 AD651 AD651 AD651 AD651
15 ∆DEAD END BEARING 1 AB519 AB519 AB519 AB519 AB519 AB519 AB519
16 ∆END CAP GASKET 1 AD644 AD644 AD644 AD644 AD644 AD644 AD644
17 DEAD END CAP 1 AD643 AD643 AD643 AD643 AD643 AD643 AD643
*** MUFFLER ASSEMBLY 1 AC990 AC990 AC990 AC990 AC990 AC990 AC990
*** MUFFLER FELT 1 AC993 AC993 AC993 AC993 AC993 AC993 AC993
*** SERVICE KIT 1 K208 K208 K281 K281 K281A K281B K208
6AM SERIES

9
EXPLODED PRODUCT VIEW, PARTS & ORDERING INFORMATION
*** Item not shown.
∆Denotes parts included in the Service Kit.
Parts listed are for stock models. For specific OEM models, please consult the factory.
When corresponding or ordering parts, please give complete model and serial numbers.
Exploded views are shown for
reference only. Units may vary
depending upon specific model.
REF# DESCRIPTION QTY 8AM-FRV-2B 8AN-NRV-5B 8AM-NRV-28A 8AM-FRV-30A 8AM-NRV-32A 8AM-NRV-42A 8AM-ARV-70 8AM-ARV-71
METRIC METRIC
1 DRIVE END CAP 1 AC835A AC835A AC988 AC835A AC988 AC835A AC988 AC988
2 ∆SHAFT SEAL 1 AC839 AC839 AB936 AC839 AB936 AC839 AK420 AK420
3 ∆O-RING 1 AC808 AC808 AC989 AC808 AC989 AC808 AC989 AC989
4 ∆DRIVE END BEARING 1 AA735B AA735B AB927 AA735B AB927 AA735B AB927 AB927
5 DOWEL PIN 4 AB162 AB162 AB162 AB162 AB162 AB162 AB162 AB162
6 DRIVE END PLATE 2 AC964 AC963 AC965 AC964 AC965 AC963 AK421 AK421
7 ∆BODY GASKET 2 AC888 AC888 AC888 AC888 AC888 AC888 AC888 AC888
8 BODY 1 AC877A AC878C AC878C AC877A AC878C AC878C AC878G AC878G
9 KEY 1 AB136D AB136D AB136D AB136D AB136D AB136D AK668 AK668
10 ROTOR ASSEMBLY 1 AC977 AC977 AC986 AC977A AC986A AC977A AC986D AC986C
11 ∆PUSH PIN 2 AC879 AC879 AC879 AC879
4 AC879 AC879 AC879 AC879
12 ∆VANE SPRING 4 AC817 AC817 AC817 AC817
8 AC817 AC817 AC817 AC817
13 ∆VANE 4 AC816 AC816 AC816 AC816
8 AC816 AC816 AC816 AC816
14 DEAD END PLATE 1 AC964 AC964 AC964 AC964 AC964 AC964 AC964 AC964
15 ∆DEAD END BEARING 1 AC894B AC894B AC894B AC894B AC894B AC894B AC894B AC894B
16 ∆END CAP GASKET 1 AC837 AC837 AC837 AC837 AC837 AC837 AC837 AC837
17 DEAD END CAP 1 AC836 AC836 AC836 AC836 AC836 AC836 AC836 AC836
*** MUFFLER ASSEMBLY 1 AC990 AC990 AC990 AC990 AC990 AC990 AC990 AC990
*** MUFFLER FELT 1 AC993 AC993 AC993 AC993 AC993 AC993 AC993 AC993
*** SERVICE KIT 1 K210 K210 K211 K283 K282 K283 K282A K282B
8AM SERIES

10
EXPLODED PRODUCT VIEW, PARTS & ORDERING INFORMATION
*** Item not shown.
∆Denotes parts included in the Service Kit.
Parts listed are for stock models. For specific OEM models, please consult the factory.
When corresponding or ordering parts, please give complete model and serial numbers.
Exploded views are shown for
reference only. Units may vary
depending upon specific model.
REF# DESCRIPTION QTY 16AM-FCC-2 16AM-FRV-2 16AM-FRV-13 16AM-FCW-28
1 DRIVE END CAP 1 AD816 AD816 AD816 AD816
2 ∆SEAL 1 AC627 AC627 AC627 AC627
3 ∆O-RING 1 AD823 AD823 AD823 AD823
4 LOCKNUT 1 AD784 AD784 AD784 AD784
5 ∆LOCKWASHER 1 AD712 AD712 AD712 AD712
6 ∆DRIVE END BEARING 1 AB777A AB777A AB777A AB777A
7 SPACER AD786 AD786 AD786 AD786
8 DRIVE END PLATE 1 AD771A AD820A AC323
9 DOWEL PIN 4 AB162A AB162A AB162A AB162A
10 ∆SPACER GASKET 2 AD788 AD788 AD788
11 BODY 1 AD770 AD819 AD819 AD770B
12 DRIVE KEY 1 AC628 AC628 AB136D AC628
13 ROTOR ASSEMBLY 1 AD775 AD794 AE807
14 ∆PUSH PIN 3 AD822 AD822
15 ∆VANE SPRING 6 AD796A AD796A
16 ∆VANE 6 AD781 AD795 AD795 AD781
17 DEAD END PLATE 1 AD773A AD821A AD821A
18 DEAD END BEARING 1 AD802 AD802 AD802 AD802
19 END CAP GASKET 1 AG406 AG406 AG406 AG406
20 DEAD END CAP 1 AG405 AG405 AD405 AG405
*** SERVICE KIT 1 K212 K213 K213 K212
16AM SERIES

11
General Information:
The product nameplate specifies all information required
when ordering parts or requests for information. The
type of lubricant required for unit is also specified on the
nameplate.
STANDARD & WORM GEAR REDUCERS - OPERATING AND MAINTENANCE INSTRUCTIONS
Product Use Criteria:
• All worm gear reducers require that the air motor be
mounted so that the intake and exhaust piping is at a
90ºangle to the centerline of the reducer output shaft.
• Gear motors are NOT self-locking. If a brake is
required for safety (for air pressure failure, etc.)
contact your Gast representative.
• Worm gear reducers are shipped with a plug in the top
pipe plug. The plug must be removed and the breather
plug installed for proper operation.
• Operating an air motor without venting will create
internal pressure build-up which can damage the
internal parts of gear motor.
• Check the oil level in units which have been stored or
not operated for a period of time.
• Gear motors require proper lubrication. Insufficient oil
level can cause loss of performance, damage or failure
of the gear motor.
Model GR11 GR20 GR25
Speed Range 33.3 to 400 RPM 30 to 300 RPM 20 to 200 RPM
(Reducer Output Shaft)
Gear Reduction 15:1 10:1 15:1
Maximum Allowable 100 lbs./45,4 kg 200 lbs/90,8 kg @300 250 lbs/113,5 kg at 200
End Thrust With RPM to 800 lbs/363,2 kg RPM to 800 lbs/363,2 kg
Zero Overhung Load. at 30 RPM at 20 RPM
(Reducer Output Shaft)
Maximum Allowable 100 lbs/45,4 kg at 333 200 lbs/90,8 kg at 300 200 lbs/90,8 kg at 200
Overhung Load With RPM to 200 lbs/90,8 kg RPM to 600 lbs/272,4 kg RPM to 600 lbs/272,4 kg
Zero End Thrust. at 33.3 RPM at 30 RPM at 20 RPM
(Reducer Output Shaft)
Lubrication Use a 300 ssu at 100˚F/38˚C turbine quality lubricant – Gast #AG292A, Gulf Harmony
53, Shell Tellus 33, Socony DTE heavy medium or Humble Nuto 53.
For horizontal operation, remove both plugs and add oil to top hole until
other hole overflows.
For vertical operation, fill to overflow point of uppermost hole.
Gear Reducer Specifications
Worm Gear Reducer Series A-F
Gear Reducer Specifications
All output shafts are in the standard location.
Model Air Motor Ratio
AG803 4AM 20:1
AG805 4AM 40:1
AG807 4AM 60:1
AG809 6AM 10:1
AG811 6AM 20:1
AG816 8AM 20:1
Change output shaft direction
1. Remove drain plug and drain oil from unit.
2. Remove end cover and seal cage cap screws.
While supporting output shaft, remove end cover
and shims from unit. Keep shims with cover.
3. Remove output shaft and seal cage together from
extension side. Keep shims with seal cage.
4. Insert seal cage, shims and sub-assembly into
housing from the side opposite from which they
were removed.
5. Insert seal cage cap screws and tighten with light
pressure.
6. Assemble end cover with shims. Insert end cover
cap screws and tighten with light pressure.
7. Turn high speed shaft in both directions to check
that gear train is running freely.
8. Cross-tighten seal cage and end cover cap
screws.
Service, Parts or Repair
For service, parts or repair of the worm gear reducer,
contact the manufacturer listed on the nameplate.

12
REF# DESCRIPTION QTY PART
NO.
1 GEAR HOUSING 1 AC737
2 GEAR HOUSING COVER 1 AC736
3 GEAR SHAFT 1 AC739
4 CLUSTER GEAR 1 AC738
5 SNAP-RING 1 AE189
6 BEARING 1 AE196A
7 SEAL 1 AA517A
8 BEARING 1 AA498
9 BEARING 1 AE195
10 O-RING 1 AD823
11 BEARING 1 AE197
12 SEAL 1 AA623D
13 SCREWS 4 BB542
14 PIPE PLUG 2 BA500
15 SET SCREW 2 BB626
*** DOWEL PIN 2 AE882
GR11 SERIES
EXPLODED PRODUCT VIEWS, PARTS & ORDERING INFORMATION
REF# DESCRIPTION QTY PART
NO.
1 GEAR SHAFT - OUTPUT 1 AE848
2 RETAINING RING 1 AE853
3 BEARING 1 AE858
4 OIL SEAL 1 AE852
5 BEARING 1 AE857
6 SCREW 6 BB652
*** DOWEL PIN 2 AF482
8 MAGNETIC DRAIN PLUG 2 AH471
9 GEAR - INPUT 1 AA294
10 OIL SEAL 1 AE851
11 HOUSING COVER 1 AE849
12 O-RING 1 AE854
13 GEAR HOUSING 1 AE850
14 GEAR SHAFT 1 AE845
15 GEAR - INTERMEDIATE 1 AE846
16 KEY 1 AE855
17 BEARING 2 AG549
18 KEY 1 AC628
GR20 SERIES
REF# DESCRIPTION QTY PART
NO.
1 BEARING 2 AG549
2 GEAR SHAFT 1 AE845
3 GEAR INTERMEDIATE 1 AE846
4 GEAR HOUSING 1 AE850
5 SEAL 1 AE851
6 SEAL 1 AE852
7 RETAINING RING 1 AE853
8 O-RING 1 AE854
9 KEY 1 AE855
10 BEARING 1 AE857
11 BEARING 1 AE858
*** DOWEL PIN 2 AF482
13 HOUSING COVER 1 AH278
14 GEAR SHAFT - OUTPUT 1 AH279
15 MAGNETIC DRAIN PLUG 2 AH471
16 SCREWS 6 BB652
17 KEY 1 AC628
GR25 SERIES
*** Item not shown.

13
MAINTENANCE RECORD
DATE PROCEDURE PERFORMED
Gast finished products, when properly installed and operated under normal conditions of use, are warranted by Gast to
be free from defects in material and workmanship for a period of twelve (12) months from the date of purchase from
Gast or an authorized Gast Representative or Distributor. In order to obtain performance under this warranty, the buyer
must promptly (in no event later than thirty (30) days after discovery of the defect) give written notice of the defect to
Gast Manufacturing Incorporated, PO Box 97, Benton Harbor Michigan USA 49023-0097 or an authorized Service
Center (unless specifically agreed upon in writing signed by both parties or specified in writing as part of a Gast OEM
Quotation). Buyer is responsible for freight charges both to and from Gast in all cases.
This warranty does not apply to electric motors, electrical controls, and gasoline engines not supplied by Gast. Gast’s
warranties also do not extend to any goods or parts which have been subjected to misuse, lack of maintenance,
neglect, damage by accident or transit damage.
THIS EXPRESS WARRANTY EXCLUDES ALL OTHER WARRANTIES OR REPRESENTATIONS EXPRESSED OR
IMPLIED BY ANY LITERATURE, DATA, OR PERSON. GAST’S MAXIMUM LIABILITY UNDER THIS EXCLUSIVE
REMEDY SHALL NEVER EXCEED THE COST OF THE SUBJECT PRODUCT AND GAST RESERVES THE RIGHT,
AT ITS SOLE DISCRETION, TO REFUND THE PURCHASE PRICE IN LIEU OF REPAIR OR REPLACEMENT.
GAST WILL NOT BE RESPONSIBLE OR LIABLE FOR INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
however arising, including but not limited to those for use of any products, loss of time, inconvenience, lost profit, labor
charges, or other incidental or consequential damages with respect to persons, business, or property, whether as a
result of breach of warranty, negligence or otherwise. Notwithstanding any other provision of this warranty, BUYER’S
REMEDY AGAINST GAST FOR GOODS SUPPLIED OR FOR NON-DELIVERED GOODS OR FAILURE TO FURNISH
GOODS, WHETHER OR NOT BASED ON NEGLIGENCE, STRICT LIABILITY OR BREACH OF EXPRESS OR
IMPLIED WARRANTY IS LIMITED SOLELY, AT GAST’S OPTION, TO REPLACEMENT OF OR CURE OF SUCH
NONCONFORMING OR NON-DELIVERED GOODS OR RETURN OF THE PURCHASE PRICE FOR SUCH GOODS
AND IN NO EVENT SHALL EXCEED THE PRICE OR CHARGE FOR SUCH GOODS. GAST EXPRESSLY
DISCLAIMS ANY WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE OR PURPOSE WITH
RESPECT TO THE GOODS SOLD. THERE ARE NO WARRANTIES WHICH EXTEND BEYOND THE DESCRIPTIONS
SET FORTH IN THIS WARRANTY, notwithstanding any knowledge of Gast regarding the use or uses intended to be
made of goods, proposed changes or additions to goods, or any assistance or suggestions that may have been made
by Gast personnel.
Unauthorized extensions of warranties by the customer shall remain the customer’s responsibility.
CUSTOMER IS RESPONSIBLE FOR DETERMINING THE SUITABILITY OF GAST PRODUCTS FOR CUSTOMER’S
USE OR RESALE, OR FOR INCORPORATING THEM INTO OBJECTS OR APPLICATIONS WHICH CUSTOMER
DESIGNS, ASSEMBLES, CONSTRUCTS OR MANUFACTURES.
This warranty can be modified only by authorized Gast personnel by signing a specific, written description of any
modifications.
WARRANTY

TROUBLESHOOTING CHART
Problem
Low Low Won’t Run Runs Hot Runs Well Reason & Remedy
Torque Speed Then Slows For Problem.
Down
●● ● Dirt or foreign material present.
Inspect and clean.
●● ● Internal rust. Inspect and clean.
●● ● ● ●Vanes misaligned. Realign vanes.
●● Low air pressure. Increase pressure.
●Air line too small. Install larger line(s).
●●Restricted exhaust. Inspect and repair.
●● ● ●Motor is jammed. Disassemble and repair.
●●Air source inadequate. Inspect and repair.
●●Air source too far from motor.
Reconfigure setup.
www.gastmfg.com
ISO 9001 & 14001 CERTIFIED
AUTHORIZED SERVICE FACILITIES
Gast Manufacturing Co., Ltd.
Beech House
Knaves Beech Business Centre
Loudwater, High Wycombe
Bucks, England HP10 9SD
TEL: [phone]
FAX: [phone]
http://www.gastltd.com
Gast Manufacturing Inc.
2550 Meadowbrook Road
Benton Harbor, MI 49022
TEL: [phone]
FAX: [phone]
www.gastmfg.com
Gast Manufacturing Inc.
505 Washington Avenue
Carlstadt, NJ 07072
TEL: [phone]
FAX: [phone]
www.gastmfg.com
Air-Oil Products Corp.
301 30th Street NE 31,#112
Auburn, WA 98002
TEL: [phone]
FAX: [phone]
www.air-oil.com
Brenner Fiedler & Assoc
13824 Bentley Place
Cerritos, CA 90701
TEL: [phone]
TEL: [phone]
FAX: [phone]
www.brenner-fiedler.com
D & F Distributors
1144 Indy Court
Evansville, IN 47725
TEL: [phone]
FAX: [phone]
www.dfdistrib.com
John Henry Foster Co.
4700 Lebourget Drive
St. Louis, MO 63134-0820
TEL: [phone]
TEL: [phone]
FAX: [phone]
www.jhf.com
Hydraulic & Pneumatic Sales
11100 Park Charlotte Blvd.
Charlotte NC 28273
TEL: [phone]
FAX: [phone]
www.hpsales.com
Wainbee Limited
5789 Coopers Avenue
Mississauga, Ontario
Canada L4Z 3S6
TEL: [phone]
FAX: [phone]
http://www.wainbee.ca
Wainbee Limited
215 boul Brunswick
Pointe Claire, Quebec
Canada H9R 4R7
TEL: [phone]
FAX: [phone]
http://www.wainbee.ca
Japan Machinery Co., Ltd
Central PO Box 1451
Tokyo, 100-91 Japan
TEL: [phone]
FAX: [phone]
or: 81-3-3571-7896
www.japanmachinery.com
James E. Watson & Co.
29 Doran Ave.
Marietta, GA 30060
Ph. 770/422-1154
www.jwatsonco.com
PART NO. 45-200 D170PL (Rev. K)