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Torque-Hub® Planetary Final Drive
S350 Series Service Manual
Rev 04/11/13
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Fairfield Manufacturing Co. Inc., Lafayette, IN, is now a part of Dana Incorporated
While every precaution has been taken in the preparation of this document, Fairfield Manufacturing Co. Inc. assumes no
liability with respect to the use of the documentation described herein, or for any act or omission of Fairfield Manufacturing
Co. Inc. concerning this documentation. Torque-Hub® is a registered trademark of Fairfield Manufacturing Co. Inc.
Features and specifications are subject to change without notice.
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Planetary Final Drive Service Manual
Content
Tightening and Torquing Bolts
Output Carrier Disassembly
1st Stage Intermediate Carrier Disassembly
2st Stage Intermediate Carrier Disassembly
Input Carrier Disassembly
Output Pinion Disassembly
Output Carrier Subassembly
1st Stage Intermediate Carrier Subassembly
2st Stage Intermediate Carrier Subassembly
Input Carrier Subassembly
Output Pinion Subassembly
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Planetary Final Drive Service Manual
Introduction
This manual is a step-by-step guide to the disassembly and
assembly of the S350 series Torque-Hub® units. It is designed for
the customer or mechanic who is repairing this particular TorqueHub® model.
Users of this manual should note that each part mentioned is
followed by an identification number enclosed in parentheses.
These part numbers may be referred to in the Parts List and
Assembly Drawing sections of this manual.
Specialized tools used to assemble this unit are noted in the
assembly procedures and diagrammed in the Assembly Tools
section.
Users should familiarize themselves with the procedures for roll and
leak testing, as well as bolt tightening and torquing found on the
following three pages before starting any repairs.
Standard safety practices should be followed during the
disassembly and assembly procedures described. Safety glasses
and safety shoes should be worn, and heavy, heat resistant gloves
should be used when handling heated components. Be especially
alert when you see the word CAUTION. This indicates that a
particular operation could cause personal injury if not performed
properly or if certain safety procedures are not followed. The word
NOTE is used to bring attention to certain procedures or helpful
hints that will aid in the disassembly and assembly process.
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Planetary Final Drive Service Manual
Roll and Leak Test
Torque-Hub® units should always be roll and leak tested before
disassembly (if possible) and after assembly to make sure the unit’s
gears, bearings and seals are working properly. The following
information briefly outlines what to look for when performing these
tests.
The Roll Test The purpose of the roll test is to determine if the unit’s gears are
rotating consistently, easily and properly. It should be able to rotate
the gears in the unit applying constant force to the roll checker. If
more drag is felt in the gears only at certain points, then the gears
are not rolling consistently and easily and should be examined for
improper installation or defects. Some gear packages roll with more
difficulty than others. Do not be concerned if the gears in the unit
seem to roll hard as long as they roll with consistency. Rotate the
gearbox both clockwise and counterclockwise the same number of
turns as the ratio of the unit. The gearbox ratio is the same number
as the last three numbers on the ID tag.
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The Leak Test The purpose of a leak test is to make sure the unit is airtight.
To perform a leak test, use the leak test fixture from the table on
page 10. If the tool is not available, the gearbox must be sealed to
perform the test. This can be accomplished by assembling the
sealed input device onto the gearbox at the input end and replace
one of the oil plugs with an air chuck. DO NOT EXCEED 10 PSI
PRESSURE DURING THE LEAK TEST. Higher pressure will create
a false sealing effect in assemblies with lip-seals. The unit has a
leak if the pressure gauge reading on your leak check fitting starts
to fall after the gearbox has been pressurized and allowed to
equalize. Leaks will most likely occur at the pipe plugs, the main
seal or wherever o-rings or gaskets are located. The exact location
of a leak can usually be detected by brushing a soap and water
solution around the main seal and where the o-rings or gaskets
meet on the exterior of the unit and then checking for air bubbles. If
a leak is detected in a seal, o-ring or gasket, the part must be
replaced and the unit rechecked. Leak test at 10 psi for 20 minutes.
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Planetary Final Drive Service Manual
Tightening and Torquing Bolts
If an air impact wrench is used to tighten bolts, extreme care should
be taken to ensure the bolts are not tightened beyond their specified
torque. The following steps describe how to tighten and torque bolts
or socket head cap screws in a bolt circle.
1.
Tighten (but do not torque) bolt “A” until snug.
2.
Go to the opposite side of the bolt circle and tighten bolt “B” until
equally snug.
3.
Crisscross around the bolt circle and tighten the remaining bolts.
4.
Use a torque wrench to apply the specified torque to bolt “A.”
5.
Using the same sequence, crisscross around the bolt circle and
apply an equal torque to the remaining bolts.
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Planetary Final Drive Service Manual
Lubrication Information
General Properties The lubricant used in most Torque-Hub® drives should be
petroleum-based gear fluid containing anti-oxidation, anti-foaming
and extreme pressure additives. The lubricant should have a
minimum viscosity index of 95 cst and maintain a minimum viscosity
of 40 cst under normal operating conditions. Some applications
require special considerations; consult the machine manufacturer
and Fairfield for more additional information.
The table below lists the recommended viscosities for various
ambient operating temperatures. These recommendations are
based on temperature rise of 50° to 100°F at normal operating
conditions.
Differential Planetary Simple Planetary
Footnotes
1. For operation in this ambient temperature range, synthetic oil is recommended with a pour point of
10°F lower than the minimum ambient temperature.
2. For operation in this ambient temperature range, synthetic oil is recommended for proper lubricant
life at elevated temperatures.
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Maintenance Oil amounts for each series of Torque-Hub® drives are indicated in
the appropriate series literature. An initial oil change should be
made after the first 50 hours of operation. Subsequent oil changes
should be made at 1,000 hour intervals or annually, whichever
comes first.
Oil temperatures should be not higher than 160° to 180°F for
continuous operation, and no higher than 200°F for intermittent
operation. For special applications, high horsepower, high speeds
or wide temperature changes, please consult Fairfield.
Oil Fill Level When the Torque-Hub® unit is mounted horizontally, unless
otherwise specified, the gearbox should be filled half-full of oil.
Consult the appropriate series literature for approximate fill
volumes. Vertically mounted Torque-Hub® units may require special
lubrication procedures. Please contact Fairfield for vertically
mounted applications.
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Planetary Final Drive Service Manual
Main Disassembly
1.
Perform a roll check and a leak check prior to disassembling the unit.
2.
Remove the two O-Ring Pipe Plugs (85) and drain the oil out of the gearbox by slightly tilting
the whole Unit.
NOTE: Record the condition and volume of the oil.
3.
Remove twenty Hex Bolts (35) from the Input Cover (5).
4.
Lift the Cover Subassembly off of the unit.
5.
Remove the O-Ring (36) out of the Unit and Discard it.
6.
Remove the Input Sun Gear (42) out of the Input Carrier Subassembly.
7.
Lift the Input Carrier Subassembly off of the unit.
8.
Remove the Ring Gear (45) out of the Unit.
9.
Remove the Thrust Washer (43) from the Intermediate Sun Gear (6).
10.
Remove the Intermediate Sun Gear (6) out of the unit.
Continued on Next Page
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11.
Remove four Socket Head Bolts (12) with Washer (13) in X pattern.
12.
Remove sixteen Hex Bolts (11) with Washer (13) in X pattern.
13.
Lift the Input Cover (5) off of the Unit.
14.
Remove two Thrust Washers (9) from the Cover (5).
15.
Remove the O-Ring (8) from the groove of the Ring Gear (18) and discard the O-Ring.
16.
Lift the Intermediate Carrier Subassembly out of the Unit.
17.
Remove the Ring Gear (18) out of the Unit.
18.
Remove the O-Ring (25) from the groove of the Ring Gear (18) and discard the O-Ring.
Continued on Next Page
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19.
Remove Intermediate Sun Gear (7) out of Intermediate Carrier Subassembly.
CAUTION: Safety glasses must be worn during these next step.
20.
Remove the Retaining Ring (26) from the external groove of the Sun Gear (7).
21.
Lift the Intermediate Carrier Subassembly out of the unit.
22.
Remove the Spacer (60) from the Output Sun Gear (23).
23.
Remove the Output Sun Gear (23) from the Unit.
24.
Remove twenty Hex Bolts (52) with Washer (53) from the Spacer Housing (29).
25.
Lift the Spacer Housing (29) Subassembly off of the Unit.
26.
Remove the O-Ring (79) out of the Spacer Housing (29) and Discard the O-Ring.
27.
Remove five Spacers (1) from the Spacer Housing (29) by removing Screws (51) from the
Spacer Housing (29).
28.
Lift the Output Carrier Subassembly out of the Unit.
Continued on Next Page
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29.
Remove the Ring Gear (24) from the Housing (32).
30.
Remove O-Ring (79) from the Housing (32) and Discard the O-Ring.
31.
Remove five Spacers (1) off of the Housing (32) by removing Screws (51).
NOTE: Refer page 23 for disassembly instruction of Output Pinion Subassembly.
32.
Turn over the Unit and remove the Output Pinion Subassembly out of the Housing (32) by
removing Hexagonal Bolts (48) with Flat Washers (49).
33.
Remove twelve Socket Head Bolts (59) from the Seal Carrier (19) and remove the Seal
Carrier (19) out of the Housing (32).
NOTE: Generally Seals should not be reused.
34.
Remove both Seals (57) from the Seal Carrier (19).
35.
Remove the O-Ring (20) from the groove of the Seal Carrier (19).
This concludes the Main Disassembly.
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Planetary Final Drive Service Manual
Cover Disassembly
1.
Remove the O-Ring (36) from groove in the Cover (46) and discard O-Ring.
2.
Remove Thrust Washers (31) from the Cover (46).
3.
Remove Thrust Bearing (39) from the Cover (46).
4.
Remove Thrust Washers (30) from the Cover (46).
5.
Remove Thrust Washers (38) from the Cover (46).
6.
Remove Thrust Washers (37) from pocket in the Cover (46).
This concludes the Cover Disassembly.