1998 HONDA CR-V rod

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
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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)
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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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Real-time 4WD-Dual Pump System
Troubleshooting (Automatic Transmissionl
When starting and accelerating in forward gesrs {4WDmodel
1. Lift up the vehicle so all four wheels are off theground (see section 1).
2. Make a mark on either No.
shaft.
'I or No.2 propeller
PROPELLER SHAFT
Start the engine, and let it run until it warms up (the
radiator fan comes on at least twice).
With the engine at idle. shift to the E position.
Apply the parking brake firmly. and measure thetime it takes the propeller shaft to rotate 10 times.. lf the measured time is more than 10 seconds,
the 4WD system is normal.
. lf the time is less than 10 seconds, there is aproblem in 4WD system. Check the differential
fluid. lf the differential fluid is normal, replace
the torque control differential case kit.
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When starting and accelerating in revGrsg gear {4WDmodel
1. Lift up the vehicle so all four wheels are off theground (see section 1).
Make a mark on either No.
shaft.
1 or No. 2 propeller
PROPELLER SHAFT
Start the engine. and let it run until it warms up (the
radiator fan comes on at least twicei.
With the engine at idle, shift to the E position.
Apply the parking brake firmly, and measure the
time it takes the proDeller shaft to rotate 10 times,. lf the measured time is more than 10 seconds,
the 4WD system js normal.. lf the time is less than 10 seconds, there is aproblem in 4WD system. Check the differential
fluid. lf the differential fluid is normal, reolace
the torque control differential case kit.
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Propeller Shaft
Inspection
Univarsal Joint and Boots
1. Shift the transmission to Neutral.
2. Raise the vehicle off the ground, and support it with
safety stands in the proper locations (see section 1).
3. Check the cente. support bearing for excessive play
or rattle. It the center support has excessive play or
raftle, replace the propeller shaft assembly.
No. 1 PROPET_LER SHAFT
Check the universal joint boots for damage and dete-
rioration. lt the boots are damaged or deteriorated,
replace the propeller shaft assembly.
Check the universal joints for excessive play or rattle.
lf the universal joints have excessive play or rattle,
replace the propeller shaft assembly.
Propellor Shaft Runout
6. Install a dial indicator with its needle on the center of
No, 1 or No.2 propeller shaft.
7. Turn the other propeller shaft slowly and check the
runout. Repeat this procedure for the other propeller
shaft.
No. 1 Propeller Shaft Runout:
Service Limit: t.5 mm (0.06 in)
No. 2 Propeller Shaft Runout:
Service Limit: 1.5 mm {0.06 inl
lf the runout on either oroDeller shaft exceeds the
service limit, replac€ the propeller shaft assembly.
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Troubleshooting
Noise and Vibration
NOTE: Pump noise in first 2 - 3 minutes after starting in cold weather is normal.
Humming
Rattle or chattering
Humming due to pulsation of fluid is normal, particularly when the wheel isturned with the vehicle stooDed.
lf equipped with automatic trans-mission, the hum could be thetorque converter or pump noase.
Confirm by temporarily removingthe pump belt.
Feed hose (high-pressure) touch-ing the frame.Beposition the feed hose.
Loose steering shaft connector,tie-rod, or balljoint.Check and tighten, or replaceparts as necessary,
Column shaft wobbling.Roplace the column assembly.
Check the rack guide for properadjustment (see page 17-15).Adjust, if necessary.
Rattling sound and feeling when turning the steering wheel right and left with th€engine OFF is normal.
Pump noise, though not loud, from the valve body unit can be heard when turn-ing the steering wheel to full lock in either direction. This is normal. Do not holdthe steering wheel at full lock lor more than five seconds when inspecting.
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Troubleshooting
Fluid Leaks
Check the gearbox assembly for oil leaks carefully. Oil can leak out ot various points, depending on location of the faulty
oil seals/seal rings. Check the following before removing the gearbox from the frame.
Steering GearboxLeaking from the oil seal on thetop of the valve housing.Replace the valve oil seal fromthe valve housing.
Leaking from cylinder end intoleft tie rod boot.Replace the valve oil seal fromthe pinion shaft.
Replace the cylinder end seal onthe valve body unit side.
Leaking from cylinder end intoright tie-rod boot.Replace the cylinder end seal onthe cylinder end side.
Leaking lrom the shaft upper endsection or pin engagement sec-tion of the pinion shaft.Replace the valve body unit.
Tighten the connector. It it's stillleaking, replace the line, cylinderor valve housing.
Leaking from cylinder line A or Bconnections (at tlare nut).
Leaking caused by a damagedcylinder line A or B.Replace cylinder line A or B.
Leaking from pump outlet hoseand return line joint fitting on thevalve body unit {at tlare nut}.
Tighten the connector. ll it's stillleaking, replace the line, joint fit-ting or valve housing,
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Steering Linkage and Gearbox
PINION SHAFT GROMMETInspoct for damage and deterioration.
STEERING JOINTSCheck for loose joint bolts.
NE-ROD LOCKNUTCheck Ior loose locknut.
Inspect for loose mounting bolts.GEARBOX MOUNTING CUSHIONSlnsp6ct for dgterioration.BOOTlnspect for damag€ and d€terioration.
BALL JONT AOOTInspoct lor damage and deterioration.S€e page 17-50 for replacemont.
END AAtL JOINTInspect for faulty movementano oamag€.
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