front wheels HONDA CR-V 1999 RD1-RD3 / 1.G User Guide
Page 444 of 1395
Removal
!@@ Make sure the lifts, i8cks. and safety stands
are placed properly {see section 1}.
1. Raise the front of the vehicle, and support it with
safety stands (see section 1).
2. Set the parking brake, and block both rear wheels
securely.
3. Drain the manual transmission fluid Reinstall the
drain plug with a new sealing washer.
4. Disconnect the heated oxygen sensor (HO2S) con-
nector.
SELF.L(rcKNGNUTReplace.
SELF-LOCKI'{GNUTReplac€.
5. Remove exhaust oipe A.
6. Make reference marks across the propeller shaft
and the transfer assembly flanges'
Separate the propeller shaft from the transfer
assembly flanges,
Remove the rear stiffener, then remove the transfer
assembly.
NOTE: While servicing the transfer assembly, do
not allow dust or other foreign particles to enter the
transmission.
7.
REFEREI{CE i'ARKS
Replace.
Replace.
13-5
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Page 656 of 1395
A/T Gear Position Switch
Replacement
@ Make 3ure lifts, iacks, and safety stands
ar€ placod properly lsoo soction 1).
1. Raise the front of the vehicle, and support it with
safety stands (see section 1).
2. Set the parking brake, and block both rear wheels
securely.
3. Shift to E position.
Remove the A/T gear position switch connector
from the connector bracket, then disconnect it.
Remove the AfI gear position switch harness clamp.
5x1.0mm12Nm11.2kgf.m,8.7 tbf.fttBRACIGT
14-140
6. Remove the harness clamp from the end cover,
then remove the Aff gear position switch cover and
Ay'T gear position switch.
A/T GEAF POSITIONswrTcH covER6x1.0mm12 N.m 11.2 kgt m.8.7 lbf.ftl
1.Set the IVT gear position switch to E position. The
AfI gear position switch clicks in E position.
POSmON
6x1.0mm12 N.m
{1.2 kg{.m,8.7 lbtftl
swlTcH
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Page 677 of 1395
Pressure Testing
Changing
NOTE: Keep all foreign particles out of the transmis-
sion.
1. Bring the transmission up to operating temperature
(the radiator fan comes on) by driving the vehicle.
Park the vehicle on level ground. turn the engane
off. then remove the drain Plug.
NOTE: lf a cooler flusher is to be used, see page
14-264 and 14-265.
TRANSMISSIONEND COVER
DRAIN18 x 1.5 mmSEALING WASHEBReplace.49 N.m {5.0 kgt.m, 36 lbf.tl)
Reinstall the drain plug with a new sealing washer,
then refill the transmission with the recommended
fluid to the uDper mark on the dipstick. Always use
Genuine Honda Premium Formula Automatic
Transmission Fluid (ATF) Using a non-Honda ATF
can affect shift quality.
Automatic Transmission Fluid Capacity:
4WD;
2.9 { (3.1 US qt. 2.6 lmp qt) 8t change
5.8 ? {7.2 US $, 6.0 lmp qt} at ovethaul
2WD:
2.7 | l2.S US qt,2.1lmp qtl ai change
5.9 ? {6.2 US $, 5.2 lmp qtl at ovolhaul
2.
a
a
1.
Wlrile testing, be careful of the rotaling wheols.
Mako sure lifts, iacks, and safety stands ar€ placed
properly (see scction 11.
Before testing, be sure the transmission fluid is
filled to the proPer level.
4WD:
Raise the vehicle (see section 11.
2WD:
Raise the front of the vehicle, and make sure it is
securely supported. Set the parking brake, and block
both rear wheels securely.
Allow all four wheels {4WD) or front wheels (2wD}
to rotate freely.
Warm up the engine (the radiator fan comes on),
then stop it and connect the tachometer.
Connect the oil pressure gauges to each inspection
hole securely, and do not allow dust or other foreign
particles to enter the inspection holes.
TOROUE: 18 N'm ll.8 kgf'm, 13 lbf'ft)
5.
A/T PRESSURE HOS€,2210 mm07MAJ - PYiOllA
{4 Requircd}
,4'/"' ,a
W'
A/T PRESSURE HOSEADAPTER07MAJ - PYt0120(il Rcquiledl
6. Measure the following Pressure:. Line Pressure ..........,14-162
. 1st. 1st-hold Clutch Pressure .............'. 14-162
. 2nd,3rd and 4th Clutch Pressure .......... 14-163
7. Install new sealing washers and the sealing bolts in
the inspection holes, and tighten to the specified
toroue.
(cont'd)
A/T OIL PRESSUREGAUGE SET W/PANEL07{06 - 0020400
/4\\-J-- (
+..\.-.\-'-\
A/T LOW PBESSUREGAUGE w/PANEL07406 - 0070300
TOROUE: 18 N'm 11.8 kgf'm, 13 lbf'ft)
14-161
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Page 680 of 1395
Transfer
4.
Inspection
@E Mako suro lifts, jacks, and safety standsare placod properly lsoe section t).
1. Raise the front of the vehicle, and make sure it issupported securely.
2. Set the parking brake, and block both rear wheelssecurely.
Shift to E position.
Make a reference mark across the propeller shaftand the transfer assembly flanges.
Separate the propeller shaft from the transferassembly.
8 x 1.25 mm32 N.m 13.3 kgl,m,24 lbf.ftlReplace.
14-164
\
6. Set a dial indicator on the transfer assembly flange.then measure the transfer gear backlash.
STANDARD: 0.06 - 0.16 mm (0.002 - 0.006 inl
7. lf the measurement is out of standard, remove thetransfer assembly and adjust transfer gear backlash{see page '14-232 thru 14-2491.
8. Check for fluid leaks between the mating faces oftransfer cover A and cover B.
9. lf there is a fluid leak, remove the cover, and reDlacethe O-ring.
'10. Check for fluid leaks between the mating face of thetransfer assembly and transmission.
11. lf there is a fluid l€ak, remove the transf€r assem-bly, and replace the O-ring,
12. Check the transfer oil seal for damage and fluidle8ks.
13, lf oil seal replacement is required. remove the trans-fer assembly, replace the oil seal, and adjust thetotal starting torque (see page 1+232 thtu ]'4-249||.
NOTE: Do not replace the oil seal with the transferassembly on the transmission.
COMPANION FLANGE
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Page 681 of 1395
Transfer Assembly
Removal
@ Make sure the lifts, iacks, and safety
stands are placed properly (see section 11.
1. Raise the front of the vehicle, and make sure it is
supported securely.
2. Set the parking brake, and block both rear wheels
securelv.
3 Drain the automatic transmission fluid (ATF).
Reinstall the drain plug with a new sealing washer'
DRAIN PLUG'18 x'1.5 rnm49 N.m 15.0 kgf.m, 36 lbl.ftl
4. Remove the guard bar and the splash shield.
GUARD 8AR
14-165
5.Disconnect the primary heated oxygen sensor
{Primary HO2S) connector.
Remove exhaust pipe A.
SELF-LOCKINGNUTBeplace.
7.
SEI-F.LOCKINGNUTReplace.
NUTReplace
Remove the shift cable cover.
Remove the snap pin and control pin, then separate
the shift cable from the control lever. Do not bend
the shift cable excessively.
(cont'd)
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Page 794 of 1395
Description
Rear Differential
Outline
The Real-time 4WD-Dual Pump System model has a hydraulic clutch and a differential mechanism in the rear differential
assembly. Under normal conditions, the vehicle is driven by the front wheels. However, depending on to the driving force
of the front wheels and the road conditions. the system instantly transmits appropriate driving force to the rear wheels
without requiring the driver to switch between 2WD (tront wheel drive) and 4WD (four wheel drive). The switching mecha-
nism between 2WD and 4WD is integrated into the rear differential assembly to make the system light and compact.
ln addition, the dual-pump system switches off the rear-wheel-drive force when braking in a forward gear. This allows the
braking system to work properly on models equipped with an Anti-lock Braking System (ABS).
Construction
The rear differential assembly consists of the torque control differential case assembly and the rear differential carrier
assembly. The torque control differential case assembly consists of the differential clutch assembly, the companion
flange, and the oil pump body assembly. The rear differential carrier assembly consists of the differential mechanism. The
differential drive and driven gears are hypoid gears.
The oil pump body assembly consists of the front oil pump, the rear oil pump, the hydraulic control mechanism, and the
clutch piston. The clutch piston has a disc spring that constantly provides the differential clutch assembly with a preset
torque to Drevent abnormal sound.
The clutch guide in the differential clutch assembly is connected to the propeller shaft via the companion flange, and it
receives the driving force lrom the transfer assembly. The clutch guide rotates the clutch plate and the front oil pump in
the oil pump body.
The clutch hub in the differential clutch assembly has a clutch disc that is splined with the hypoid drive pinion gear. The
hypoid drive gear drives the rear oil pump.
The front and rear oil pumps are trochoidal pumps. The rear oil pump capacity is 2.5 percent larger that the front oil pump
to handle the rotation difference between the front and rear wheels caused by worn front tires and tight corner braking.
The oil pumps are designed so the fluid intake works as a fluid discharge when the oil pumps rotate in reverse. Genuine
Honda CVT fluid is used instead of differential fluid.
Operation
When there is a difference in rotation speed between the front wheels (clutch guide) and rear wheels (hypoid driven gear),
hydraulic pressure from the front and rear oil pumps engages the differential clutch, and drive force from the transler
assembly is applied to the rear wheels.
The hydraulic pressure control mechanism in the oil pump body selects 4WD mode when the vehicle is started abruptly,
or when accelerating in a forward or reverse gear (causing rotation difference between the front and rear wheels). or
when braking in reverse gear {when decelerating). lt switches to 2WD mode when the vehicle is driven at a constant speed
in forwar! or reverse gear (when there is no rotation difference between the front and rear wheels), or when braking in a
fo rwa rd gear (when decelerating).
To protect the system, the differential clutch assembly is lubricated by hydraulic pressure generated by the oil pumps in
both 4WD and 2WD modes. Also, the thermal switch relieves the hydraulic pressure on the clutch piston and cancels 4WD
mode if the temDerature of the differential fluid rises above normal.
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Page 796 of 1395
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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Page 797 of 1395
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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Page 798 of 1395
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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Page 802 of 1395
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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