Subaru 2009 IMPREZA Service Manual page 1979

(10) Piston stroke calculation
Calculate with A and B dimensions recorded
before. If the calculated value exceeds the ser-
vice limits, replace the drive plate and select
and adjust the retaining plate to be within initial
standard values.
T = A + B
T: Piston stroke
A: Amount of drive plate compression
B: Clearance between retaining plate and snap
ring
Initial standard:
1.1 — 1.4 mm (0.043 — 0.055 in)
Limit thickness:
1.6 mm (0.063 in)
Retaining plate
Part No.
31567AA910
31567AA920
31567AA930
31567AA940
31567AA950
31567AA960
31567AA970
31567AA980
AT Main Case
Thickness mm (in)
4.0 (0.157)
4.2 (0.165)
4.4 (0.173)
4.6 (0.181)
4.8 (0.189)
5.0 (0.197)
5.2 (0.205)
5.4 (0.213)
4AT-123
AUTOMATIC TRANSMISSION
2. PLANETARY GEAR AND LOW CLUTCH
1) Apply ATF to a new D-ring, and install it to the
low clutch piston.
2) Install the low clutch piston to low clutch drum.
NOTE:
Be careful not to damage the D-ring.
(A) Low clutch piston
(B) Low clutch drum
3) Install the spring retainer to low clutch piston.
(A) Spring retainer
(B) Low clutch drum
4) Attach the ST to the low clutch drum.
ST 498437100 LOW CLUTCH PISTON
GUIDE
(A)
(B)
AT-00269
(A)
(B)
AT-00270
ST
AT-00271