1990 MITSUBISHI ECLIPSE Service Manual

3-6REAR AXLE - Viscous Coupling Type Limited Slip Differential
Is
Side gear (L.H.)
Side gear (R.H.)1Differential case B
Pinion shaft
Thrust
washer
Viscous cokpling
3r
Side gear U3.H.)Differential case
B
, ,,Differential cover
I
‘Gear cagierPir
,Drive pinionfront bearing
Driv& pinionDrive gear
Bearing caprear bearing
ICokpanion flangellAo337
Normal operating range
Hump region
Difference in rotating speed between
right and left wheels (rpm)
RemarkslA hump occurs when there is a large differencein rotatinwheels..!speed between the right and leftlnce the large difference causes
violent shearing of the silicone oil in the
viscous couplin7.by the plates, the oil tempera-
ture rises (the SI Icone 011 expands), and the
torque abruptly rises. If the hump occurs, the
inner and outer plates enter a directly coupled(differential locked) state.llAOO5r
FUNCTIONS AND FEATURES(1) The viscous coupling type limited-slip differential
is functionally the same as
the conventional
mechanical type which reduces slipping of the
rear wheels for better performance when travel-
ing on a rough road or when getting out of a
snowy or muddy surface.
(2) The viscous coupling type limited slip differential
responds to a difference in rotating speed and
has outstanding characteristics for use in an
on-road
4WD vehicle, as it has no difference in
characteristics in the normal operating range
between when power is ON and when it is OFF,
and provides better straight ahead stability and
running performance.
(3) When a single wheel is slipping, a hump could
cause the differential to approach a locked state.
Provision is therefore made to provide a better
ability to get out even in cases of one in a million
such as a stuck state.

REAR AXLE -Viscous Coupling Type Limited Slip Differential3-7CONSTRUCTION
Rear drive
/shaft (L.H.)Serration coupled
ElDrive pinion
Rear driveshaft (R.H.1
11Po070The viscous coupling type limited differential is a
“shaft-shaft” type consisting of the right and left
rear drive shafts and viscous coupling directly
coupled. The viscous coupling is a unit filled with
silicone oil and consists of the outer plates @
coupled with the case @ , the inner plates @
coupled with the viscous coupling hub
(j) , and the
spacer rings @ arranged alternately to hold one
plate and angther with only a small spacing in
between. The X-rings @ are provided to prevententry of the differential oil into the viscous coupling.
The rear drive shaft
(L.H.) is serration coupled with
the viscous coupling case @ and coupled
,via the
case with the side gear
(L.H.) @which is in a single
body with the-viscous coupling case.
The rear drive shaft
(R.H.) is serration coupled with
the side gear
(R.H.) and its end serration coupled
with the viscous coupling hub
0) .
The viscous coupling must not be disassembled.

w
3-8REAR AXLE - Viscous Coupling Type Limited Slip Differential
OPERATIONDrive force smaller
I(Slipping side)Drive force larger(Grippina side)
Rear drive shaft
(L.H.1 (Left wheel)
resistance smaller)Rear drive shaft
(R.H.1 (Right wheel)
11 PO071If a difference in rotating speed occurs between the
right and left wheels, the viscous coupling case @
and viscous coupling hub @ relatively rotate with
the same difference in rotating speed as the rear
drive shafts. As a result a differential limiting torque
is generated by the shear resistance of silicone oil
and helps suppress the differential (slipping).For example, assume that the right wheel rotates at
20 rpm due to the road surface resistance, whereas
the left wheel rotates at 30 rpm. The difference in
rotating speed between the right and left wheels is
10 rpm. Since the viscous coupling is provided
between the right and left wheels, a differential
limiting torque compensating for the difference of
10 rpm in rotating speed is transmitted from the left
wheel to the right one.
Therefore, a larger drive force is transmitted to the
right wheel rotating at the lower speed.

REAR AXLE- Differential Support Member3-9
DIFFERENTIAL SUPPORT MEMBER
ROJFAAAThe differential support member supports the rear
side of the differential carrier. That end of the
member which is mounted to the body is elastically
supported by use of rubber bushings.
Section A-ADifferential support
member
llA0297
cDifferential
support member
\Differential carrier

BRAKES
CONTENTS

5-2
FEATURES

BRAKES - Service Brakes 5-3
$eTandem (with level sensor)
(718)
Brake boosterTYpeEffective dia. of
y3tt$;ivacuum-boost type
powmermc&;der
Proportioning valve Type Dual type
(597)
kPa (psi)
Decompression 0. 3
(15/l 6)
Multiple-vacuum-boost type
c
4,200 (597)
TypeM-R44VM-R44V
cyhnxLy.53.9 (2’/8) 53.9 (2%)
Clearance Automatic Automati
c
I
TypeAD30PAD30P
Cyl~itl;.~. 30.1 (13/16) 30.1 (13/16)
Clearance Automatic Automatic
*:4WD
X
ARRANGEMENT OF BRAKE LINES

5-4
Braki disc 14A0531
Section A-A
14AO530
,ad Shim
014A0532

Disc wheel
.