oil capacity HONDA CR-V 1999 RD1-RD3 / 1.G User Guide

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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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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Maintenance
Differential Fluid
!@ Make sure lifts are placed properly lseesection 1).
1. With the vehicle on level ground, inspect differential
fluid with engine OFF.
2. Remove the oil filler plug, then check the level andcondition of the fluid.
Proper Level
o|I FII.IIR PI-UG4t N.m la.8 kgl.m, 35 lbl.ftl
The fluid level must be up ro the fill hole. lf it isbelow the hole, add the recommended fluid until itruns out, then reinstall the oil filler plug with a new
wasner.
lf the differential tluid is dirty, remove the drainplug, and drain the fluid.
4.
DMIN PLUGa7 N.m 14.8 kgl.m, 35 lbt.ftl
15-14
Clean the drain plug, then reinstall it with a new
washer, and refill the differential with the recom-
mended fluid to the proper level.
NOTEr lf you disassembly the differential, check thefluid level again after the 4WD system check is fin-
ished. Add fluid if necessary.
Reinstall the oil filler plug with a new washer.
Fluid Capacity
1.0 / {1.1 US $, 0.9 lmp qt) at tluid change
1.2 / {1.3 US $, 1.1 lmp qt) at oyerhaul
Recommended fluid:
Genuine Honda CVT Fluid
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Charging
Use only service equipment that is U.L.-listed and is cer-
tified to meet the requirements of SAE J2210 to remove
HFC-134a (R-134a) from the air conditioner system.
CAUTION: Exposure to air conditioner refrigerant and
lubricant vapor or mist can irritate eyes, nose and
throat. Avoid breathing th€ air conditioner refrigerant
and lubricant vapor or mist.
lf accidental system discharge occurs, ventilate work
area before resuming service. Additional health and
safety information may be obtained from the relrigerant
and lubricant manufacturers.
Connect a R-'134a refrigerant recovery/recycling/charging
station to the vehicle, as shown. following the equipment
manufacturer's instructions.
R€covery/Recycling/Charging Station
HIGH-PRESSURESIDE
Add the same amount of new refrigerant oil to system
that was removed during recovery. Use only SP-'10
refrigerant oil.
Charge the system with Required amount of R-134a
refrigerant. Do not overcharge the system; the compres-
sor will be damaged.
Select the appropriate unit of measure for your
charging station.
Refrigerant capacity: 700 to 750 g
0.70 to 0.?5 k9
1.5 to 1.6 lbs.
21.7 to 26.5 oz.
ll-
22-61
Leak Test
Use only service equipment that is U.L.-listed and is cer-
tified to meet the requirements of SAE J2210 to remove
HFC-134a (R-134a) from the air conditioner system.
CAUTION: Exposure to air conditionor refrigerant and
lubricant vapor or mist can irritate eyes, nose and throat.
Avoid breathing the air conditioner retrigerant and lubri-
cant vapor or mist.
lf accidental system discharge occurs, ventilate work
area before resuming service.
R-134a service equipment or vehicle ajr conditioner sys-
tems should not be pressure tested or leak tested with
compressed arr.
!@ some mixturos of air and R-1348 have
been shown to be combustible at olovatod pres3uras
and can result in fire or explosion causing iniury or
property damage. Never use comprelised air to pressure
test R-13ila service equipment or vehicle air conditioner
systems.
Additional health and safety information may be obtained
from the refrigerant and lubricant manufacturers.
2.
1.Connect a R-134a refrigerant recove rylrecycling/
charging station to the vehicle, as shown in the pre-
vious column, following the equipment manufactur-
er's instructions.
Open the high-pressure valve to charge the system
to the specified capacity, then close the supply
valve, and remove the charging system couplers.
Select the appropriate unit of measure for your
charging station.
Refrigerant capacity: 700 to 750 g
0.70 to 0.75 kg
1.5 to 1.6 lbs.
21.7 to 26.5 oz.
Check the system for leaks using a R-134a refriger-
ant leak detector with an accuracy of 14 g (0.5 ozl
per year or better.
lf you find leaks that require the system to be opened
(to repair or replace hoses, fittings, etc.), recover the
system according to the Recovery Procedure on page
22-59.
After checking and repairing leaks, the system must
be evacuated (see System Evacuation on page 22-601.
5.
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