2-M6
ZD18(F) · ZD21(F) · ZD28(F), WSM
TRANSAXLE
(5) Oil Flow
(A) ZD18(F) · ZD21(F)
[Serial No. Affected: below 20000]
The pump and motor are joined in a closed hydraulic loop and most of oil circulates within the main oil circuit. A
little oil lubricates and oozes out from the clearance between the moving parts of the case. Then oil in the main oil
circuit of the HST needs to be supplied a want.
The charge oil is sent to the HST housing after the control valve and oil filter pass with the hydraulic pump.
The charge oil aids smooth operation of pistons for pump and motor. And overflow oil from HST housing return to
the transmission case.
(1) Oil Strainer
(2) Transmission Case
(3) Hydraulic Pump
(4) Control Valve
(5) Regulator Valve
(6) PTO Clutch
(7) Oil Filter Cartridge
(8) Check Valve
(9) Lubricating Orifice
(10) Cylinder Block (Pump)
(11) Swashplate
(12) Piston
(13) Cylinder Block (Motor)
(14) Neutral Orifice