Neilw,
What you need is a tractor/hydraulic fluid of approx. ISO 46 or SAE 30 weight oil.
These oils have special formulations for wet clutch apps and areused for gearing and hydraulics as well.
Below is a swipe for am Amsoil spec Sheet:
APPLICATION
AMSOIL Synthetic Tractor Hydraulic/Transmission Oil is Recommended for Applications Requiring the Following Specifications:
Tractors
Case International - MS-1207, HYTRAN
Caterpillar - TO-2, TO-3
Deutz-Allis - All
Ford - M2C41-B, M2C134-D, M2C86-B
Hesston/Fiat - All
John Deere - Quatrol®, J20C, J20D, J14C
Kubota, UDT - All
Landini - All
Massey-Ferguson - M1127-B, M1129-A, M1135 and M1141 (also known as Permatran III®)
Steiger - All
Versatile - All
Transmissions
Detroit Diesel Allison Division - C-4 Hydraulic Systems
ABEX/Denison - HF-0, HF-1, HF-1A, HF-2, HF-2A
Cincinnati Milacron - P-70
Sundstrand - HMS-103
Sperry New Holland - 767166, 287530
Sundstrand Hydraulics, HMS-103
® Registered Trademarks
PERFORMANCE DATA
AMSOIL Synthetic Tractor Hydraulic/Transmission Oil exceeds the following rigorous performance requirements:
Caterpillar Friction Retention Test - Pass
Denison Pump Test (T5D Vane Pump, 46 Series Piston Pump) - Pass
Deutz-Allis Friction Retention Test - Pass, Deutz-Allis Turbo Hydra-Matic Oxidation Test - Pass, Deutz-Allis Power Steering Pump Test - Pass
Ford 7710 IPTO Stall Test - Pass, Ford 7710 Brake Capacity - Pass, Ford 7710 Brake Chatter Test - Pass
John Deere JDQ-42 PTO Clutch (2000) Cycles - Pass, John Deere JDQ-40 Brake Capacity Test - Pass, John Deere JDQ-40 Brake Torque Variation (Chatter) - Pass, John
Deere JDQ-73 Cold Soak @ -35°C - Pass, John Deere JDQ-74 Slow Cool @ -30°C - Pass, John Deere JDQ-74 Slow Cool @ -35°C - Pass
Massey Ferguson MF-285 PTO Clutch - Pass, Massey Ferguson MF-285 Wet Brake Chatter and Torque Characteristics - Pass
Plessy-Sundstrand Gear Pump Test - Pass
Sundstrand Model 22-2132 Variable Displacement, Piston Pump - Pass
Vickers 35VQ-25, Pump Test - Pass
INSTALLATION
AMSOIL Hydraulic/Transmission Oil is fully compatible with conventional hydraulic/transmission oils. To install AMSOIL Hydraulic/Transmission Oil in a hydraulic system,
drain the existing hydraulic/transmission oil, change filters and install AMSOIL Hydraulic/Transmission Oil.
TYPICAL TECHNICAL PROPERTIES
AMSOIL Synthetic Tractor Hydraulic/Transmission Oil (ATH)
ISO Grade
46
SAE Viscosity
30
Kinematic Viscosity @ 100°C, cSt (ASTM D-445)
9.3
Kinematic Viscosity @ 40°C, cSt (ASTM D-445)
50.1
Viscosity Index (ASTM D-2270)
171
Flash Point °C (°F) (ASTM D 92)
230 (446)
Fire Point °C (°F) (ASTM D 92)
242 (468)
Pour Point °C (°F) (ASTM D 97)
-40 (-40)
Four Ball Wear Test (ASTM D 4172B) Scar, mm
0.35