Drive Range-Third Gear

Drive Range - Third Gear:

DRIVE RANGE-THIRD GEAR

CONVERTER CLUTCH - APPLIED
SECOND CLUTCH - APPLIED
THIRD CLUTCH - APPLIED
THIRD ROLLER CLUTCH - HOLDING

As vehicle speed increases, governor pressure overcomes Throttle Valve (T.V.) pressure and 2-3 throttle valve spring pressure to open the 2-3 shift valve. With the 2-3 shift valve in this position, the following changes take place in the hydraulic circuit:

The Input Clutch Releases: Line pressure is blocked from entering the input clutch passage and input clutch oil pressure is exhausted.

The 1-2 Servo Releases: Drive 4 pressure is blocked from entering the 2-3 accumulator exhaust passage and the 2-3 accumulator exhaust passage is opened to exhaust. This causes check ball #5 and #6 to seat and the 2-3 accumulator valve to regulate the oil on the apply side of the 1-2 servo into an accumulator oil pressure that is proportional to modulator pressure.

The Third Clutch Applies: Third clutch oil is directed to the following:
a. Third Clutch Check Ball (4): Orifices the feed to the third clutch.
b. Release Side of the 1-2 Servo: Releases the 1-2 servo by pushing the 1-2 servo piston down against the accumulator oil pressure on the apply side of the 1-2 servo. This also acts as an accumulator for the third clutch.
c. Third Clutch Piston: Applies the third clutch.
d. 3-4 Shift Valve: Feeds the fourth clutch when in Fourth Gear.
e. 1-2 Accumulator: Boosts accumulator pressure slightly for the 3-4 shift.

SUMMARY
The input clutch and the 1-2 band are released. The second clutch is driving the input carrier; the third clutch prevents the input sun gear from turning faster than turbine speed and the input sun gear and input carrier together drive the input internal gear in direct drive.