Operation CHARM: Car repair manuals for everyone.

Drive Range-1ST Gear

In this ran the converter is filled, the forward clutch is applied and the transmission is in Drive range-first gear.

With selector in Drive position, the manual valve is positioned to permit line pressure to enter the drive passage. Drive oil then flows to the following:

1. Forward clutch.
2. Governor assembly.
3. 1-2 shift valve.
4. 1-2 accumulator valve.

Drive oil is directed to the forward clutch through an orifice where it acts on the clutch piston to apply the forward clutch.

Drive oil is direct to the 1-2 shift valve, and then to the 1-2 accumulator valve and is regulated to a pressure called 1-2 accumulator pressure. This pressure is directed to the 1-2 accumulator piston to act as a cushion for the band apply on a 1-2 shift

Drive oil at the governor assembly is regulated to another variable pressure which is called governor pressure. Governor pressure increases with vehicle speed and acts against the 1-2 and 2-3 shift valves and the 3-2 control valve.