Oil differential HONDA CR-V 1999 RD1-RD3 / 1.G User Guide

Differential
Rear Differential
Special Tools .......... ...........15-2
Description
Rear Differential ................................. 15-4
Hydraulic Flow ............ ,.. 15-6
Real-time 4WD-Dual Pump System
Troub|eshootin9 ................................. 15-10
Rear Differential Assembly
Troubleshooting ................................. 15-13
Maintenance
Differential Fluid ........... . 15-14
Rear Differential Assembly
lllustrated Index .......... .. 15-15
Removal/lnstallation .... 15-16
Differential Carrier Assembly
Leak Repair .................... 15-18
OilSeals
Replacement ...,................................... 15-19
Rear Differential Assembly
Disassembly ..........,......., 15-20
Reassembly .................... 15-23
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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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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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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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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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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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7. Insert the edge of the screwdriver into the groove
located under the differential housing Pry out the
driveshaft inboard ioint with a screwdraver.
NOTE: Take care not to damage the differential oil
seal and differential ring when prying out the differ-
ential inboard joint.
8. Remove the mounting bolts and the washers.
DRIVESHAFT
MOUNTING BOLTS'10 x 1 .25 mm,19 N'm (5 0 kgf m, 36 lbtftl
Lower the rear differential assembly on the trans-
mission jack, then remove the rear driveshafts from
the rea r difterential assembly.
DIFFERENTIAL
12 x 1.25 fifi
10. Remove the rear difterential mounting bracket A
from the rear differential assembly.
N.m {7.0 lgf.m. 5l lbl.tt)
REAR DIFFERENTIALMOUNTING BRACKET A
REAN DFFERENTI,ALASSEMBLY
11.Install the rear differential assembly in the reverse
order of removal.
Note these items during reassembly
. lnstall the breather tube to the breather tube joint
properly.
. During the propeller shaft installation, align the
marks on the propeller shaft and companion
flange.
. Reiill the rear differential with the recommended
fluid to the proper level {see page 15-14).
15-17
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Differential Carrier Assembly
Leak Repair
'1. Remove the bolts in a crisscross oattern. thenremove the differential housing.
I x 1.25 mm22 N.m 12.2 kgl.m, 16 tbtftlDIFFERENTIAL HOUSING
2.Apply liquid gasket to the sealing surface of the dit-ferential housing, and note these items:. Use liquid gasket (P/N 08718 - 000'1).. Remove any dirt or fluid from the sealing sur-lace.
. lf 20 minutes have passed after applying liquidgasket, reapply it before you assemble the hous-
ings. Allow it to cure at least 30 minutes afterassembly before filling differential with ftuid.
DIFFERENTIALHOUSING
15-18
Install the differential housing. then torque the boltsin a crisscross pattern in several steps.
Install the oil seals (see page 15-19).
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Oil Seals
Replacement
1. Remove the oil seals from the differential housing.
Right side:
Left side:
2. Install the oil seals squarely using the special tools.
Be carelul not to damage the lip ol the oil seals.
Right side: Installation depth of the oil seal is 9 mm
(0.35 in) below the edge of the differential housing.
OIL SEAL
OIL SEAL
Left side: Install the oil seal flush with the edge of
the differential carrier assembly.
OIL SEAL
HUB DIS/ASSEMBLY TOOL07965 - 6920101
(cont'd)
15-19
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Oil SealsRear Differential Assembly
Replacement (cont'd)
3. Remove the oil seal from the toroue control differ-
ential case.
Install the oil seal squarely using the special tool.careful not to damage the lip of the oil seal.
15-20
BREATHER TUBE
DRAIT{ PLUG
Disassembly
1. Remove the breather tube, the drain plug and the oilfiller plug.
OIL FILI.IR PLUG
Raise the locknut tab from the groove of the clutchguide, making sure that the tab completelv clearsthe groove to prevent damaging the clutch guide.
L(rcKNUT, 24 mmReplace.
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