Cub Cadet Domestic Series 7000 User manual

Service Manual
Domestic Series 7000 Compact Tractor
MTD Products Inc. - Product Training and Education Department
FORM NUMBER - 769-01634
12/2004
NOTE: These materials are prepared for use by trained technicians who are experienced in the service and repair of equipment of the
kind described in this publication, and are not intended for use by untrained or inexperienced individuals. Such individuals should seek
the assistance of an authorized service technician or dealer. Read, understand, and follow all directions when working on this equip-
ment. This includes the contents of the Operators Manual, which came with your equipment. No liability can be accepted for any inac-
curacies or omission in this publication, although every care has been take to make it as complete and accurate as possible. The right
is reserved to make changes at any time to this document without prior notice and without incurring an obligation to make such
changes to previously published documents. All information contained in this publication is based on product information available at
the time of publication. Photographs and illustrations used in this publication are for reference use only and may not depict actual
model and component parts.
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Domestic Series 7000 Hydraulics
Orientation ................................................................................................................. 1
Hydrostatic Drive: Basic Operation ............................................................................ 4
External Checks ......................................................................................................... 6
Best Practices: Hydraulic Systems ............................................................................ 8
Flow and Pressure tests: Hydrostatic Drive ............................................................... 8
Auxiliary Pumps ....................................................................................................... 11
Steering Pump and Cylinder .................................................................................... 14
Hydraulic Lift Cylinder and Control Valve ................................................................ 18
Tandem Pump ......................................................................................................... 22
Loader Valve ............................................................................................................ 24
Component Breakdown: Auxiliary Pump (tandem pump similar) ............................. 26
Component Breakdown: Steering Unit ..................................................................... 28
Domestic Series 7000 MFD
Identify the MFD: ...................................................................................................... 31
MFD Removal: Preparation ..................................................................................... 33
Removal ................................................................................................................... 34
MFD Installation ....................................................................................................... 36
In-Frame Repairs: Drop Axle Service ...................................................................... 37
In-Frame Repairs: Drop Axle Cover ......................................................................... 38
In-Frame Repairs: Drop-Axle Removal .................................................................... 40
Bench Repairs: Drop axle and kingpin housing assemblies .................................... 42
Bench Repair: Axles and Differential. ...................................................................... 46
Torque Specifications .............................................................................................. 57
Domestic Compact Dash and Steering Pump
Dash Panel Removal ............................................................................................... 59
The Dash Panel ....................................................................................................... 63
Steering Shaft and Pump: Sauer ............................................................................. 65
Steering Shaft and Pump: Ross ............................................................................... 67
Domestic Series 7000 Damped Driveshaft
Preparation: ............................................................................................................. 69
Driveshaft Removal .................................................................................................. 69
Electrical System
Electrical System ...................................................................................................... 72
Componants.............................................................................................................. 73
Eelstric Clutch and Fuel Pump.................................................................................. 81
TABLE OF CONTENTS
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Domestic Series 7000 Hydraulics
1
1. STANDARD HYDRAULIC SYSTEMS ON THE
DOMESTIC SERIES 7000: ORIENTATION
NOTE: Subsections 1 and 2 of the Domestic
Series 7000 Hydraulics portion of this manual
provide a basic orientation to the system. Sub-
section 3 and those that follow it contain specific
test procedures.
NOTE: Hydraulic diagrams are contained in an
apendix to this section.
1.1. The transmission housing acts as a reservoir for
all of the hydraulic systems on the tractor: hydro-
static drive pump, hydrostatic steering system,
lift cylinder, and accessories.
1.2. Fluid: the transmission and hydraulic system are
filled with 6.5 gallons (24.6 L) of Cub Cadet
Hydraulic Transmission Fluid (P/N: 737-3025
1Qt., 737-3062 1Gal., 737-3063 10 Qt., 737-
3035 5 Gal.).
1.3. Filtration: The hydraulic system filter (P/N:723-
0405) is located on a boss on the front surface of
the transmission housing, adjacent to the mid-
mount, 2000 R.P.M. P.T.O. shaft. The hydro-
static drive filter (P/N: 723-3014) is located on
the front surface of the hydrostatic pump.
See Figure 1.3.
NOTE: Other than sharing a reservoir, the
hydrostatic drive operates independently of the
rest of the hydraulic system.
Figure 1.3
Hydrostatic
Drive Filter
Hydraulic system
filter
1.4. The hydrostatic drive is a Sauer model BDU15.
It has an integrated gerotor charge pump that
draws fluid up the suction pipe from the base of
the transmission housing. See Figure 1.4.
1.5. The steering and lift cylinder are powered by a
Sauer-Danfoss SKP 1/4.3 S auxiliary pump.
1.6. If hydraulically powered accessories are
installed, they are driven by a second auxiliary
pump that mounts to and is driven by the stan-
dard auxiliary pump. The add-on auxiliary pump
is a Sauer-Danfoss model SNP 1/7.8 S.
NOTE: Domestic Series 7000 tractors produced
before 2004 included a single auxiliary pump as
standard equipment. Later tractors include both
auxiliary pumps and the valve used to operate a
front-end loader.
Figure 1.4
Hydrostatic
drive pump
Auxiliary
pump
Second auxiliary
pump
Domestic Series 7000 Hydraulics
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1.7. The steering pump, located in the dash pedestal
contains it’s own back-up gerotor charge pump
that will enable steering control when the engine
is not running. See Figure 1.7.
1.8. The steering pump directs fluid pressure to one
end of the double-acting differential steering cyl-
inder while allowing it to return from the other
end of the cylinder in order to provide steering
action.
1.9. The lift cylinder is operated by a control valve
and feedback rod under the right rear fender.
See Figure 1.9.
1.10. The control valve directs fluid pressure to a sin-
gle-acting hydraulic cylinder that lifts the three-
point lift arms.
1.11. The hydraulic fluid flow is as follows:
1.12. Through the pick-up tube from the transmission
sump and filter, to the auxiliary pump.
See Figure 1.12.
1.13. Under pressure from the auxiliary pump the fluid
goes to the steering pump, connecting to the “P”
port on Sauer steering pumps. On Ross steer-
ing pumps, it connects to the “IN” port.
Figure 1.7
Steering
pump
Figure 1.9
From Steering
unit
To lift cylinder
To return manifold
Direct return
Figure 1.12
Auxiliary pump
Filter
Flow
Figure 1.13
Auxiliary pump
(steering and
lift cylinder)
Line to
steering
unit
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1.14. The steering unit distributes pressure to the
steering cylinder according to the position of the
steering wheel. On Sauer pumps this involves
the ports labeled “L” and “R”. See Figure 1.12.
1.15. On Ross pumps, this involves the ports labeled
“LT” and “RT”. See Figure 1.14.
Figure 1.14
Sauer steering unit:
note labeled ports
Figure 1.15
RT
LT
OUT IN
AUX
1.16. The power steering unit is first in line, and has
priority over the rest of the system. From the
steering unit, the fluid may follow one of two
return paths:
1.17. The fluid may pass through the return manifold,
through the oil cooler, then back to the transmis-
sion. See Figure 1.17.
1.18. The oil cooler is located on the front of the radia-
tor. See Figure 1.18.
Figure 1.17
Return
manifold
To cooler
From steering unit
“T” port on Sauer
“OUT” port on Ross
Unused ports
capped
valve
From lift
Figure 1.18
Oil
cooler
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Domestic Series 7000 Hydraulics
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1.19. If the fluid is required by the lift cylinder, it will go
to the bottom port of the lift valve instead of the
return manifold.
1.20. The lift valve sends fluid to the single-acting lift
cylinder when operator demand and the feed-
back rod direct it to do so. See Figure 1.20.
1.21. Fluid not required to lift the cylinder will be
directed back to the transmission through the
return manifold, via the cooler. See Figure 1.21.
1.22. Excess fluid volume beyond normal return flow
rate is generated when the lift arms are lowered.
This flow is exhausted directly back into the
transmission housing.
2. HYDROSTATIC DRIVE: BASIC OPERATION
2.1. The input shaft to the D15U turns a shaft that
passes completely through the housing of the
hydro., driving an engine speed input shaft in the
transmission.
2.2. The input shaft drives the auxiliary hydraulic
pump and the P.T.O. They are driven at rela-
tively constant engine speed, rather than in rela-
tion to ground speed. See Figure 2.2.
2.3. The input shaft also turns a gerotor style charge
pump and an axial piston variable displacement
hydraulic pump. See Figure 2.3.
NOTE: Figure 2.3 is a similar model hydrostatic
drive unit with some see-through components.
Figure 1.20
Lift
cylinder
rod
Feedback
Figure 1.21
Line from return
manifold and oil cooler
Lift valve
Direct return line from
lift cylinder (when lowered)
To return
manifold
Figure 2.2
Auxiliary
hydraulic
pump
Input
shaft
for PTO
Hydro.
Figure 2.3
Charg
e
pump
Charge check valves
Fixed displacement
motor
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2.4. The lower part of the pump contains a fixed dis-
placement axial piston hydraulic motor. The
motor is driven by the output of the variable dis-
placement pump.
2.5. The hydro. control arm (scissors bracket) moves
a swash plate that controls the output of the
pump: tilting the swash plate in one way causes
the variable displacement pump to drive fluid
through the fixed displacement pump in one
direction. See Figure 2.5.
NOTE: In figure 2.5, the pistons in the variable
displacement pump are alternately pressed into
the bores, and then released from bores of the
rotating pump block by the tilt of the swashplate.
• On the right side of the pump block in figure 2.5,
the pistons are down.
• The pistons are extended on the left side of the
pump block. They are forced up by springs con-
tained in the pistons.
• This action causes the pistons to pump fluid in
one direction.
• The further the swash plate is tilted, the greater
the movement of the pistons as the pump block
rotates.
• As the travel of the pistons is increased, the dis-
placement of the pump is increased, and more
fluid is pumped.
• The more fluid is pumped, the faster the fixed
displacement motor is driven.
Figure 2.5
Input shaft
Fixed displacement
motor
Variable displacement pump
Pump
block
angle
Swash plate
Swash
plate
Motor block
2.6. Tilting the swash plate the other way causes the
variable displacement pump to drive fluid
through the fixed displacement pump in the
opposite direction. See Figure 2.6.
2.7. When the swash plate is flat, the pump pistons
do not move up and down, no fluid is displaced
and no power is transmitted to the fixed dis-
placement pump.
2.8. The charge pump maintains a supply of pressur-
ized fluid to the variable displacment pump to
feed and lubricate the pump.
2.9. The charge check valves direct the flow of pres-
surized fluid to the ports that feed the pistons of
the variable displacement pump.
• When driving forward, fluid flows into the
varaible displacment pump thorugh one set of
ports, and out through a second set.
• When driving backwards, the flow is reversed.
• One check valve opens and the other one
closes, depending on the direction of fluid flow.
• If the hydro. is in “neutral”, lubrication is provided
to ths spinning (but not pumping) pump and
motor blocks through separate channels in the
housing.
2.10. If the hydrostatic drive is not performing cor-
rectly, begin diagnosing with simple things that
can bee seen with minimal disassembly.
Figure 2.6
S
was
h
p
l
a
t
e
angle
Pistons
Pistons
Fixed displacement
motor
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3. EXTERNAL CHECKS
NOTE: Linkage adjustment procedures are cov-
ered in the 2003 Cub Cadet Technical Hand-
book, pages 6-129 through 6-131.
3.1. Remove the fender cover using a phillips head
screwdriver and a 1/2” wrench. See Figure 3.1.
NOTE: It will be necessary to pry-up the inside
edges of the black rubber floor pads to get the
fender cover off.
3.2. If the transmission creeps, or the tractor fails to
achieve normal ground speed, check the neutral
control adjustment and control linkages to the
hydro. See Figure 3.2.
NOTE: Complete neutral control adjustment pro-
cedures can be found in the 2003 Cub Cadet
Technical Handbook, page 6-129 through 6-131
3.3. If the brake and drive pedals “fight” with each
other, the drive control linkage is out of adjust-
ment. See Figure 3.3.
3.4. If the tractor fails to achieve normal ground
speed, and the hydro pump emits an unusual
amount of noise, check for brake drag:
• Confirm that the neutral return and hydro control
linkages are correctly adjusted.
• With the tractor on a smooth, firm, level surface,
place the gear selector in neutral, release the
parking brake, and attempt to push the tractor.
• If the tractor does not roll with a reasonable
amount of effort, check the brakes.
• The left and right brakes can be checked individ-
ually by jacking-up the rear of the tractor and
attempting to rotate the rear wheels individually.
Leave the transmission in neutral.
• If either or both brakes drag, confirm that the
linkage moves firmly and is properly adjusted.
• If the linkages are properly adjusted, and brake
drag is still present, remove the wheel and brake
assembly on the side that drags. Inspect the
brake assembly.
NOTE: Complete brake adjustment procedures
can be found in the 2003 Cub Cadet Technical
Handbook, page 6-131 through 6-133.
Figure 3.1
Fender cover
Bolts
Holes for
screws
Foot pad
Figure 3.2
Shoulder
bolt
Neutral
return
assembly
Figure 3.3
Hydro control
rod
ferrule
Adjustment
Forward shaft
assembly
Brake shaft
assembly
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