1998 HONDA CR-V rear

TOROUE CONTROL OIFFERENTIAL
REAR DIFFERENTIAL ASSEMBLY
OIL PUMP BODY
OIFFERENTIAL CLUTCHHYPOID DRIVEPINION GEAR
OIFFERENTIAL CARRIER
DIFFERENTIAL
HYPOID RING GEAR
DIFFERENTIAI- HOUSING
REAR OII- PUMP
ASSEMBLY
CLUTCH GUIDE
COMPANION FLANG€
CLUTCH HUB
CLUTCH PLATE
HYDRAULIC CONTROL SYSTEM
CLUTCH PISTON
CLUTCH DISC
REAR OIL PUMP
FRONT OIL PUMP
DISC SPRINGFRONT OIL PUMP
DIFFEREMT|AL CLUTCHASSEMBI-Y
THERMAL SWITCHRELIEF VALVEOIL STRAINER
15-5
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Description
Hydraulic Flow
Forward Start and Acceleration l4WD)During a forward start and forward acceleration, the dual pump system can engage four wheel drive.lf the front wheels spin faster than the rear wheels, the front oil pump spins faster than the rear oil pump. The front pump
draws fluid through check valve B and discharges it. Some of the discharged fluid is drawn in the by the rear oil pump.The remaining fluid will pass through check valve E into the clutch piston. There, hydraulic pressure is regulated by twoorifices.
The regulated hydraulic pressure at the clutch piston pushes the plates and discs of the clutch together to form a connec-tion. The engaged clutch then passes driving force from the transfer assembly to the rear wheels, producing 4WD.
oRrFtcEsFRONT OIL PUMPREAR OIL PUMP
Forward Driving at Constant Speed lzWD)When driving forward at a constant speed (cruising), the dual pump system functions in two wheel drive mode.The rotation speed of the front and rear wheels is the same, so the speed of the front and rear pumps is also the same.Fluid discharged by the front oil pump is drawn in by the rear oil pump and is circulated through the system. Becausethere is no pressure built up at the clutch piston, the clutch does not engage, and the vehicle remains in 2WD (front wheeldrive).
FRONT OIL PUMP
15-6
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Forward Deceleration l2WDl
During forward deceleration, the dual pump system functions in two wheel drive mode.
Because of braking characteristics, the speed of the rear wheels may exceed the speed ol the front wheels during deceler-
ation. lf so, the rear oil pump spins faster than the front oil pump.
Fluid discharged by the rear oil pump is simply drawn in again by the rear pump and recirculated. Because there is no
pressure built up at the clutch piston. the clutch piston does not engage, and the vehicle remains in 2WD (front wheel
drive).
Reverse Start and Acceleration (4WD)
During reverse start and reverse acceleration, the dual pump system can engage four wheel drive.
lf the front wheels spin faster than the rear wheels, the front oil pump spins faster than the rear oil pump. The front oil
pump draws in fluid through check valve A and discharges it. {Note that in reverse, the direction of the pumps is the oppo-
site of that during forward driving.)
Some of the fluid that is discharged by the front oil pump is drawn in by the rear oil pump. The remaining fluid passes
through check valve F into the cylinder of the clutch piston, where it is regulated by two orifices.
The regulated hydraulic pressure at the clutch piston may force the plates and discs of the clutch together to form a con-
nectlon. The engaged clutch passes driving force from the transfer assembly to the rear wheels, producing 4WD.
oRtFtcEsFRONT OIL PUMP
{cont'd)
15-7
REAR OIL PUMP
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Description
Hydraulic Flow (cont'dl
Reverse Driving at Constant Speed l2WD)when driving in reverse at a constant speed, the dual pump system functions in two wheel drive mode.The rotation speed of the front and rear wheels is the same, so the speed of the front and rear pumps is also the same,Fluid discharged by the front oil pump is drawn in by the rear oil pump and is circulated through the system. But, becausethe there is a difference in the capacity between the two pumps, fluid flows through check valve E, and then through ori-Iices. This fluid lubricates and cools the clutch assembly and bearings.ls this condition, only a low pressure is built up at the clutch piston. Therefore the clutch does not engage, and the vehicleremains in 2WD (front wheel drive).
Reverse Deceleration l/tWDl
During reverse deceleration, the dual pump system can engage four wheel drive.When decelerating in reverse direction, the speed of the rear wheels may exceed the speed of the front wheels (due toengine braking). In this condition, the rear oil pump draws fluid through check valves B and C. Fluid discharged from therear oil pump then flows through check valve E to the clutch piston. There, pressure is regulated by two orifices.The regulated hydraulic pressure at the clutch piston may force the plates and discs of the clutch together to form a con,nection. The engaged clutch passes driving force from the transfer assembly to the rear wheels, producing 4WD.
oRtFtcEsREAR OIL PUMP
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Thermal Switch Operation l2WD)
During 4WD operation, pressure-regulated fluid is in contact with the clutch piston and the thermal switch.
lf the temperature of the fluid in the differential goes too high, the thermal switch pushes open the relief valve R. This
causes the pressure in the clutch piston to drop, and 4WD mode is disengaged.
THERMAL SWITCHRELIEF VALVE
Reliet Valve Operation
When the fluid pressure goes higher than the relief valve spring force, check valve R opens. Pressure applied at the clutch
piston is held constant. This feature adds stability by preventing the rear wheel drive system from experiencing excessive
to rque.
RELIEF VALVE
15-9
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Real-time 4WD-Dual Pump System
Troubleshooting (Automatic Transmission/Manual Transmission)
Whon d6c6l6rating in a torward gear {2WD mode}
1. Block the front wheels, raise the left rear wheel. and
support it with a safety stand as shown.
Hold the tire and turn it counterclockwise continu-
ouslv for more than one rotation.
lf the rotation of the wheel does not gradually
feel heavy while rotating, the 2WD system when
decelerating in a forward gear is normal.
lf the rotation of the wheel gradually feels heavy,
there is a problem in the system. Check the dif-
ferential fluid, lf the fluid is normal, reDlace the
toroue control differential case kit.
WHEEL CHOCKS
15-12
When decelerating in reverse gear (4WD mod€)
1. Block the front wheels. raise the left rear wheel, and
suppo( it with a safety stand as shown.
Hold the tire and turn it clockwise continuouslv for
more than one rotation.
lf the rotation of the wheel gradually feels heaw.
the 4WD system when decelerating in reverse gear
is normal,
lf the rotation of the wheel does not gradually feel
heavy, there is a problem in the system. Check
the differential fluid. lf the fluid is normal.
reolace the torque control differential case kit,
WHEEL CHOCKS
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Rear Differential AssemblY
Troubleshooting
Most problems in the unit are to be diagnosed by identifying noises from the gears or bear'ngs'
care should be taken during diagnosis not to confuse differential noises with those from other drivetra'n components'
SymptomProbable CauseRemedy
Will not go into 4WD mode. Fluid level too low
. Incorrect fluid type
. Add fluid. Replace
Will not return to 2WD modeIncorrect fluid typeDrain and fill the differential
Gear or bearing noisesFluid level too low
Incorrect fluid type
Damaged or chipped gears
Add fluid
Drain and fill the differential
Replace the differential carrier
assemory
Overheating. Fluid leveltoo low
. Incorrect fluid type
. Add fluid. Drain and fill the differential
Fluid leakFluid level too high
Clogged breather hose
Worn or damaged oil seal
Damaged sealing washer
Loose mounting bolts or inade-
quate sealing
Lower to proper level
Clean or replace
Replace
Replace
Recheck torque or aPPIY sealant
15-13
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Rear Differential Assembly
lllustrated Index
O.RINGReplace.
6xl.0m12 N.m (1.2 kgf m,8.7 lbt'ftl
BACK-UP RING
COMPANION FLANGE
CLUTCH HUB/PLATES/DISCS
DIFFERENNAL CLUTCHASSEMBLY
DOWEL PINS
OIL PUMP DRIVESHAFT
LOCKNUT, 24 mmReplace.118 N.m (12.0 kgtm.87 rbt ft)
OIL SEALReplace.
PRESSURE PLATE
THBUST NEEDLEAEARING""t",at\(
'd'
CLUTCH GUIDE
OIL PUMPPIN
e
MAGNET
6x1.0mm12 N.m 11.2 kgt'm,8.7 lbf'ft|
OIL STRAINER
15-15
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