Like everyone else said, you can use any oil that is rated for diesel engines. I have always used the New Holland/Case Ambra oil. If you buy another oil, I would make sure it meets (or closely meets) Ambra oil specs. I am not sure I would put in hydro oil that required a bottle of dry gas, but that is up to you.
New Holland-Ambra
Mastergold HSP Engine Oil
Mastergold HSP Engine Oil (MAT- 3507)
A superior diesel engine oil
Mastergold HSP Engine Oil is a premium, high performance engine oil, specifically designed and tested to provide maximum protection, performance, and life, for the heavy-duty, high temperature operation of construction, agricultural, and other off-road diesel-powered equipment.
Provides superior protection against wear and corrosion. Helps keep engines exceptionally clean, minimizing deposits and maintaining excellent soot control.
Excellent cold-weather starting and operating performance.
Extensively tested and approved by CNH Engineering to provide outstanding performance in heavy-duty diesel engines operating under the most severe conditions.
Available in SAE viscosity grades
10W (NH-301C)
10W30 (NH-324H)
30 (NH-303C)
15W40 (NH-330H)
20W50 (NH-336G)
40 (NH-304C)
New Holland-Ambra
Multi-G 134 Fluid
Multi-G 134 Fluid (NH-410B)
A Multi-Purpose hydraulic / transmission fluid
Multi-G 134 is a single fluid for hydraulic systems, transmissions, differentials, wet brakes and PTO clutches. A high quality hydraulic oil that is truly all-purpose. Designed for use in an ambient temperature range of -5F (-20C) to 120F (50C).
Friction modifiers and anti-wear additives provide protection from abrasion and scoring to crucial components.
Superior wear protection for hydraulic components, drive train gears and other transmission parts.
Surpresses wet brake chatter, and enhances brake stopping capacity, including PTO brakes.
Provides good filterability for optimum hydraulic system performance.
Controlled frictional characteristics provide smooth operation of wet brakes and clutches.
Thoroughly tested and approved by CNH engineering. Meets NH specification NH-410B.