Page 29 - Hydra-matic 6 Speed RWD Technician's Guide (October 2005)

APPLY COMPONENTS - 4-5-6 CLUTCH

plates. This disengages the 4-5-6 clutch plates (434), and clutch plate
assemblies (433), from the backing plate (432) and disconnects the 4-5-6
(w/turbine shaft) housing assembly (441) from the hub assembly (58), thus
the output carrier will not be driven at torque converter turbine speed.
The clutch apply cavity is kept full of fluid by the clutch exhaust backfill
circuit. Compensator feed fluid is fed into the cavity behind the piston to
counteract the centrifugal pressure forces created by the fluid within the
apply cavity. The compensator feed fluid assists the clutch return spring to
keep the piston in the released position when commanded off.
4-5-6 If the 4-5-6 clutch apply fluid does not completely exhaust from behind the
(W/TURBINE SHAFT) piston, there could be a partial apply, or drag, of the 4-5-6 clutch plates. If
CLUTCH the 4-5-6 clutch is inoperative, there will be no 4th, 5th or 6th gears
ASSEMBLY
(56) available.
4-5-6 CLUTCH:
The 4-5-6 clutch assembly is located in the 4-5-6 (w/turbine
shaft) housing assembly (441), which is splined to the torque 4-5-6 4-5-6 4-5-6 4-5-6 4-5-6
converter turbine assembly. The external teeth on the 4-5-6 (W/TURBINE SHAFT) CLUTCH CLUTCH CLUTCH CLUTCH
clutch plates (434) are splined to the 4-5-6 clutch housing HOUSING SPRING PISTON PLATE BACKING
while the internal teeth on the 4-5-6 clutch plate assemblies ASSEMBLY (438) DAM (434) PLATE
(433) are splined to the 4-5-6 clutch (w/output carrier shaft (441) ASSEMBLY (432)
(437)
and dampener) hub assembly (58). The 4-5-6 clutch is
applied when the transmission is in 4th, 5th, or 6th gear
ranges, to transfer engine torque to the output carrier
assembly (68).
4-5-6 CLUTCH APPLY:
To apply the 4-5-6 clutch, 4-5-6 clutch COMPENSATOR 4-5-6
fluid is fed through the fluid pump FEED CLUTCH
cover (219), through the turbine FLUID PISTON
DAM
shaft, and behind the piston RETAINING
assembly (439). 4-5-6 clutch RING
fluid pressure moves the (436)
piston to compress the
spring (438). As fluid
pressure increases, the
piston compresses the
clutch plates until they are
held against the backing
plate (432). Also included
in the assembly is a 4-5-6
clutch (waved) plate (435) that TURBINE
helps cushion the apply of the 4-5-6 SHAFT FLUID
clutch. Behind the piston is a piston SEAL RING 4-5-6
dam assembly (437), which acts as the back (442) CLUTCH
side of the compensator fluid cavity. When APPLY
fully applied, the clutch plates (434), clutch plate FLUID
assemblies (433), and 4-5-6 clutch (waved) plate (435) are
locked together, thereby holding the housing assembly and the
hub assembly (58) together. Since the output carrier (490) is
splined to the hub assembly, this forces the 4-5-6 clutch and the
output carrier to rotate at the same speed as the torque converter
turbine assembly.
4-5-6 4-5-6 4-5-6 4-5-6
4-5-6 CLUTCH RELEASE: CLUTCH CLUTCH CLUTCH CLUTCH
PLATE
PISTON
To release the 4-5-6 clutch, 4-5-6 clutch fluid exhausts from the ASSEMBLY (WAVED) ASSEMBLY BACKING
PLATE
PLATE
piston, through the turbine shaft and into the fluid pump cover (439) (435) (433) RETAINING
(219). Spring force from the 4-5-6 clutch spring (438), and RING
compensator feed fluid, moves the piston away from the clutch (431)
442 441 439 438 437 436 435 434 433 432 431

20 Figure 20