Subaru SVX 1992 Manual page 403

3- 2 [MBAO] AUTOMATIC TRANSMISSION AND DIFFERENTIAL
8 . Band Brake
~
A: CONSTRUCTION
Rev. clutch drum
Lock nut
- Washer
-~~-' O-ring
- Pin anchor end
Brake band ASSY
Strut
Band servo piston stem
Return piston spring
Band servo piston
Band servo retainer
O.D . servo retainer
Retainer
Band servo piston `0 .D . return spring
O. D.
C3-006
Fig. 14
The band brake consists of a flex type brake band, a
band brake adjusting mechanism, two servo pistons,
two retainers, two return springs, a stem, a strut, and
others . The band brake can be adjusted as installed on
the vehicle .
~ B: FUNCTION
"' O
I Piston stem
Band servo piston
3R
2A
UI)
Band servo piston O.D .
(III)
(A)
(B
C3-007
Fig . 15
One end of the brake band is secured to the transmis-
sion case via the brake band adjusting screw.
When no hydraulic pressure is applied to the servo
piston from the hydraulic pressure controller, the servo
piston and band servo piston O.D . are forced down-
ward by the return spring, as shown in (A) of the Figure .
When hydraulic pressure 2A is applied to the servo
chamber (II), it causes the band servo piston to come
into contact with the stepped portion of the band servo
piston stem, thereby pushing the band servo piston
stem upward to state (B). Under this condition, the
brake band slowly tightens the reverse clutch drum and
fixes the front sun gear of the front planetary gear . (2nd
speed state)
Next, when the release pressure 3R to the servo cham-
ber (I) and the hydraulic operating pressure 2A to the
servo chamber (II) are applied simultaneously, the band
servo piston is pushed downward by the force of the
return spring and the pressure difference between
chamber (I) and chamber (II), caused by the difference
in operating areas of the band servo pistons. Under this
condition, state (A) is resumed, and the brake band
loosens and releases the reverse clutch drum . (3rd
speed state)
O Piston stem
I
Band servo piston
i
3R
2A
Drain
_ 4A
Band servo piston O.D . (C)
(AI
C3-008
Fig. 16
12