Service Manuals, User Guides, Schematic Diagrams or docs for : . Car Manuals Subaru Impreza 2001-2002.2004-2007 Approved Subaru Impreza 2004 WRX STi 08. MECHANISM AND FUNCTION 40. DIFFERENTIALS 03. Limited Slip Differential (LSD) (Mechanical Type)
<< Back | HomeMost service manuals and schematics are PDF files, so You will need Adobre Acrobat Reader to view : Acrobat Download Some of the files are DjVu format. Readers and resources available here : DjVu Resources
For the compressed files, most common are zip and rar. Please, extract files with Your favorite compression software ( WinZip, WinRAR ... ) before viewing. If a document has multiple parts, You should download all, before extracting.
Good luck. Repair on Your own risk. Make sure You know what You are doing.
Image preview - the first page of the document
>> Download 03. Limited Slip Differential (LSD) (Mechanical Type) documenatation <<
Text preview - extract from the document
W1860BE.book Page 9 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
3. Limited Slip Differential (LSD) (Mechanical Type)
A: GENERAL
When controlling the differential action between left and right wheels during cornering or when ei-
ther of the wheels spins due to slip or bumping, cams will expand the pressure rings to press the
friction plates together, thus enabling the driving torque be transmitted to the non-spinning wheel
too for more stable driving.
This differential is suitable for high powered and high output torque vehicles also because it re-
sponds to the acceleration pedal operation quickly.
DI-9
W1860BE.book Page 10 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
B: CONSTRUCTION
Pressure rings with V-grooves are assembled in the case of the mechanical differential. The four
lugs (protrusions) on the periphery of the pressure rings fit in the grooves provided inside the differ-
ential case when the pressure rings are assembled, and the pressure rings can slide in axial direc-
tions.
The tips of the pinion shaft are chamfered to assemble the pinion shaft into the V-grooves of the
pressure rings, forming V-shaped cams. Similar to the pressure rings, the friction plates and spring
plates also have four lugs (protrusions) on the periphery and these lugs fit in the grooves provided
inside the differential case when the plates are assembled.
On the internal circumference of the friction disks and spring plates there are 4 or 6 lugs (protru-
sions) which fit in the grooves provided on the outer circumference of the side gears, and the friction
disks and spring plates can slide in axial directions.
These friction plates, friction disks, spring plates, spring disks are alternately arranged and form a
clutch as a whole.
The spring plates and spring disks act as Belleville springs and provide initial torque. Moreover,
thrust washers are inserted between the side gears and differential case halves to adjust clearance
in the axial direction and prevent thrust from the side gears to work against the pressure rings.
DI-10
W1860BE.book Page 11 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
(19)
(2)
(1)
(16)
(14)
(15)
(18)
(13)
(12)
(17)
(11)
(10)
(9)
(8)
(7)
(6)
(3)
(5)
(4)
DI-00340
(1) Ring gear (8) Side gear (15) Spring plate
(2) Differential case RH (9) Pinion (16) Friction disc
(3) Spring disk (10) Pinion shaft (17) Friction disk
(4) Thrust washer (11) Side gear (18) Spring disk
(5) Spring plate (12) Pressure ring (19) Differential case LH
(6) Friction plate (13) Friction plate
(7) Pressure ring (14) Thrust washer
DI-11
W1860BE.book Page 12 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
C: OPERATION
The torque transmitted from the crown gear to the differential case is then transmitted to the pres-
sure rings via their four lugs (protrusions) causing the pressure rings and the differential to rotate
as a unit.
The torque is further transmitted from the pressure rings to the V-shaped cams of the pinion shaft
causing reaction force F opposing the rotational direction and load P=Fcot in the axial directions
to be applied on the cam faces.
The reaction force F opposing the rotational direction is transmitted through the pinion gears to the
side gears in the same way as a conventional differential. The force P in axial directions push open
the pressure rings and act as engaging load for the multi-plate clutchs.
This load is needed as a force to cause friction between the friction plates and friction disks to let
them work as clutchs.
(3)
2F (1)
P P
(2)
R R
F F
DI-00341
(1) Pinion shaft F: Reaction force that occur when the pressure rings
cause the pinion shaft to rotate in driving direction.
(2) Pressure ring P: Reaction force which the pressure rings receive from
the pinion shaft in axial direction and this reaction
force becomes the clutch engaging load.
(3) Rotational direction
DI-12
W1860BE.book Page 13 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
1. WHEN RIGHT AND LEFT WHEELS ROTATE AT THE SAME SPEED
During normal straight-ahead driving where the right and left wheels rotate at the same speed, the
differential case and side gears rotate together, just as in conventional differentials. As a result, driv-
ing torque is distributed equally to the right and left side gears.
DI-00342
DI-13
W1860BE.book Page 14 Tuesday, January 28, 2003 11:01 PM
LIMITED SLIP DIFFERENTIAL (LSD) (MECHANICAL TYPE)
DIFFERENTIALS
2. WHEN RIGHT AND LEFT WHEELS ROTATE AT DIFFERENT SPEEDS
The right differential bevel gear tries to turn faster than the differential case, however, since the right
differential bevel gear is braked by the clutch, a part of the torque is transferred from the right differ-
ential bevel gear via the clutch to the differential case as shown by the broken line.
While the left wheel is not spinning and the differential bevel gear is turning at a low speed, the dif-
ferential case is turning at a high speed, and in contrast with the right side, torque is transferred from
the differential case via the clutch to the differential bevel gear.
As a result, the left side differential bevel gear receives a torque which is transferred from the right
side differential bevel gear through the clutch, differential case, left side clutch and left side differen-
tial bevel gear, in addition to the torque transferred from the differential bevel pinion via the differen-
tial bevel gear.
When right wheel spins
DI-00343
D: SERVICE PROCEDURES FOR LSD
It is not recommended to disassemble the LSD assembly as component parts of LSD assembly are
not available individually.
DI-14
◦ Jabse Service Manual Search 2026 ◦ Jabse Pravopis ◦ onTap.bg ◦ Other service manual resources online : Fixya ◦ eServiceinfo