TM-9-2520-215-34

TM 9--2520--215--34

0005 00--11

THEORY OF OPERATION -- CONTINUED

0005 00

HYDRAULIC SYSTEM – Continued

Action of Hydraulic System in Reverse Range, Converter Drive, No Steer

NOTE

Refer to Torque Path in Reverse Range, Converter Drive, No Steer Schematic View and

Hydraulic System, Reverse Range, No Steer Schematic View.

In reverse range, the hydraulic system functions as described in neutral range operation. The only differences are:

The reverse range clutch is applied.

The out pressure and brake coolant pumps operate in a reverse direction. The oil passage from the range

selector to the top of the main pressure regulator valve is exhausted.

When the range selector valve directs pressure to the reverse range clutch, lockup cannot occur. Therefore, although

the throttle position may actuate the lockup relay valve, the valve will have no function.

The brake coolant pump reverse rotation draws air (or air/oil mixture) from the lines leading to the output reduction

gear assemblies. The air or mixture is discharged at the air valve, which is open when brakes are released. This loss

is negligible.

The output--driven pressure pump reverse rotation reallocates a small portion of the oil pumped by the input--driven

pump.

When the line at the top of the main pressure regulator valve is exhausted, main pressure is higher, as it is during low

range. The shift inhibitor will prevent a shift to any other range, above certain output speeds. Refer to Downshift In-

hibitor Limits

07i216m

Torque Path in Reverse Range, Converter Drive, No Steer Schematic View

REVERSE RANGE

CLUTCH APPLIED

DIRECTION OF TRAVEL

TM-9-2520-215-34 - Page 39 of 508