Product Overview

The ROCKEFELLER 8# Hydraulic Transmission Oil is a specialized multi-functional fluid designed for the unique requirements of combined hydraulic and power transmission systems found in off-highway construction and agricultural equipment. Unlike dedicated hydraulic oils (which only serve hydraulic circuits) or dedicated gear oils (which only serve gear trains), the 8# is engineered to perform multiple functions simultaneously within a single, interconnected fluid system:

1. Hydraulic fluid function: Transmitting power through hydraulic pumps, motors, valves, and cylinders for steering, implement control, and braking systems
2. Torque converter fluid function: Transmitting power through the hydrodynamic torque converter that couples the engine to the transmission
3. Powershift transmission fluid function: Lubricating and cooling the clutch packs, planetary gear sets, and bearings within the powershift transmission
4. Wet brake fluid function: Lubricating and cooling the wet disc brakes (oil-cooled brakes) used in many off-highway machines
5. Final drive lubricant function (in some systems): Lubricating planetary reduction gears in axle and hub assemblies that share oil with the transmission

The “8#” designation corresponds to the viscosity specification — specifically No. 8 hydraulic transmission oil as defined by Chinese national standard GB/T 6364, which specifies a kinematic viscosity of approximately 56–72 cSt at 40°C. This viscosity grade is optimized for the combined requirements of hydraulic power transmission and mechanical gear/clutch lubrication in medium and heavy construction equipment.

The critical challenge in formulating a hydraulic transmission oil is balancing opposing friction requirements:

• Clutch friction: Powershift transmission clutches and wet brakes require the oil to provide specific friction characteristics — high static friction for positive engagement, controlled dynamic friction for smooth transitions, and consistent friction over time (no “fade” during extended operation). If the oil’s friction characteristics are wrong, clutches slip (causing power loss and overheating), engagement is harsh (causing shock loads and operator discomfort), or brakes lose effectiveness (creating a safety hazard).
• Gear and bearing lubrication: Gear teeth and bearing surfaces require the oil to minimize friction to reduce power loss and heat generation.
• Hydraulic performance: Hydraulic system components require the oil to have appropriate viscosity, low compressibility, good air separation, and chemical stability.

The 8# is formulated with a carefully balanced additive package that delivers optimal performance across all of these competing requirements — a formulation achievement that requires deep expertise in tribology, fluid chemistry, and equipment engineering.

The 8# is manufactured to international quality standards with a five-year shelf life and is available in 18-liter buckets and 208-liter drums.

Key Functional Features and Performance Benefits

Oxidation and Thermal Stability

★ Excellent Oxidation Stability and Thermal Stability — Oil Products Not Easy to Deteriorate Under Harsh Operating Conditions:
Hydraulic transmission systems in construction equipment operate under severe thermal conditions:

• Torque converter heat generation: Hydrodynamic torque converters generate enormous amounts of heat during stall and converter range operation — particularly during low-speed, high-load operations like bulldozer dozing, loader digging, and grader cutting. Oil temperatures in the torque converter can exceed 120–150°C.
• Clutch heat generation: Each powershift transmission gear change involves clutch pack engagement and disengagement, generating heat through friction. In high-duty-cycle applications (loader loading trucks, grader making repeated passes), clutch packs may cycle hundreds of times per hour.
• Wet brake heat generation: Oil-cooled brakes on wheel loaders, articulated dump trucks, and motor graders generate significant heat during downhill travel, approach to load, and emergency stops.
• Hydraulic system heat generation: Pressure drops across valves, flow through restrictive passages, and internal pump leakage all convert hydraulic energy into heat.

The 8#’s oxidation and thermal stability ensures the oil maintains its chemical integrity under these sustained high-temperature conditions, preventing:

• Varnish and lacquer deposits on clutch plates (which alter friction characteristics and cause erratic shifting), valve spools (which cause sticking and slow response), and cooler passages (which reduce heat transfer efficiency)
• Sludge formation that blocks filter elements, oil passages, and cooler tubes
• Viscosity increase from oxidation polymerization (which increases parasitic losses and reduces hydraulic system responsiveness)
• Acid formation that corrodes copper alloy components, attacks seal materials, and degrades clutch friction surfaces

Emulsification Resistance and Seal Compatibility

★ Good Emulsification Resistance, Foam Resistance, and Compatibility of Sealing Materials:
Construction equipment operates in environments where water contamination is nearly inevitable — rain, condensation, pressure washing, and water crossing all introduce moisture into the oil system. The 8#’s emulsification resistance (demulsibility) ensures that water separates from the oil rapidly rather than forming a stable emulsion. Water-in-oil emulsions are extremely damaging because they:

• Accelerate oxidation and corrosion
• Reduce the oil’s load-carrying capacity
• Cause cavitation and erosion in pumps and motors
• Degrade clutch friction characteristics
• Promote microbiological growth (bacteria and fungi) that further degrade the oil

The foam resistance prevents the formation of stable foam in the reservoir and within the system, maintaining system integrity and precision as described in the 46# hydraulic oil section above.

The seal material compatibility ensures that the 8# does not damage the various elastomeric seals throughout the interconnected hydraulic/transmission system — which may include different seal materials in different subsystems (e.g., NBR in hydraulic cylinders, FKM in transmission clutch piston seals, polyurethane in brake actuators). The 8# is compatible with all common seal materials, maintaining seal integrity and preventing the leaks that cause system pressure loss, environmental contamination, and safety hazards.

Clutch and Transmission Performance

★ Ensure Short Clutch Coupling Time, Fast Gear Changes, and Smooth Hydraulic Transmission Operation:
This is the defining performance characteristic of the 8# — the ability to deliver optimal friction characteristics for powershift transmission clutches and wet brakes while simultaneously serving as an effective hydraulic fluid and gear lubricant.

Short Clutch Coupling Time:
When the operator selects a new gear, the transmission control system engages the appropriate clutch pack by applying hydraulic pressure to force the friction discs and separator plates together. The time from initial clutch plate contact to full engagement (coupling time) must be short — typically 0.3–0.8 seconds — to provide responsive, positive gear changes. If the oil’s friction coefficient is too low, the clutch plates slip for too long before locking up, causing sluggish gear changes, power loss, excessive heat generation, and accelerated clutch wear. The 8# is formulated to provide the high coefficient of friction required for rapid, positive clutch engagement.

Fast Gear Changes:
In a powershift transmission, gear changes involve the simultaneous release of one clutch pack and engagement of another (or in some designs, the engagement of additional clutch packs for higher gears). The oil must provide consistent, predictable friction characteristics across all clutch packs to ensure smooth, fast transitions without harsh engagement shock or momentary power interruption. The 8#’s friction modifier chemistry is calibrated to deliver this consistency.

Smooth Hydraulic Transmission Operation:
The torque converter is a hydrodynamic coupling that transmits engine torque to the transmission through fluid dynamics rather than mechanical contact. The oil within the torque converter circulates at high velocities between the impeller (connected to the engine), the turbine (connected to the transmission input shaft), and the stator (a fixed reaction member). The 8#’s viscosity-temperature characteristics and foaming resistance ensure smooth, efficient torque converter operation across the full operating range — from stall (maximum torque multiplication, maximum heat generation) through coupling (lock-up, direct drive) to overrunning (coast-down).

Efficiency and Durability

★ Reduce Transmission Loss and Variable Speed Impact:
Every component in the power transmission path — from the torque converter through the transmission, transfer case, and final drives to the wheels or tracks — absorbs some of the engine’s power as friction, churning, and windage losses. The 8#’s balanced formulation minimizes these parasitic losses while maintaining the friction levels required for clutch and brake performance. This means:

• More of the engine’s power reaches the ground, improving machine productivity
• Less heat is generated within the transmission system, reducing cooling system load
• The machine operates more efficiently, consuming less fuel per unit of work accomplished
• Gear ratio transitions are smoother, reducing the mechanical shock loads (variable speed impact) that stress drivetrain components, structural members, and operator comfort

★ Excellent Abrasion Resistance, Rust Resistance, and Corrosion Resistance:
The 8#’s anti-wear additive system protects all critical wear surfaces within the interconnected hydraulic/transmission system:

• Gear teeth: Planetary gear sets in the transmission, transfer case, and final drives experience high contact pressures and sliding velocities
• Bearings: Tapered roller bearings, needle bearings, and sleeve bearings throughout the transmission and drivetrain
• Clutch plates: The friction and separator plates must maintain their surface characteristics over thousands of engagement cycles
• Brake discs: Wet brake friction and separator discs must resist wear while maintaining consistent braking performance
• Hydraulic pump and motor components: Pistons, valve plates, gears, vanes, and other precision surfaces within the hydraulic circuit
• Valve spools and bores: Directional, pressure, and flow control valves throughout the system

The comprehensive rust and corrosion protection guards all system metals — including the copper alloys commonly used in clutch plate facings, thrust washers, and bushings — against moisture-induced corrosion and acid attack.

Technical Specifications

Parameter	8# Hydraulic Transmission Oil
Product Type	Hydraulic Transmission Oil (Multi-Functional)
Chinese Standard	GB/T 6364 (No. 8)
Application Focus	Construction Machinery
Kinematic Viscosity @ 40°C	~56–72 cSt
Oxidation Stability	Excellent
Thermal Stability	Excellent
Emulsification Resistance	Good
Foam Resistance	Good
Seal Compatibility	Multiple Elastomers
Clutch Friction Performance	Optimized (Short Coupling Time)
Gear Shift Quality	Fast, Smooth
Anti-Wear	Excellent
Rust/Corrosion Protection	Excellent
Copper Compatibility	Yes
Torque Converter Compatibility	Yes
Wet Brake Compatibility	Yes
Available Packaging	18L Bucket, 208L Drum
Shelf Life	5 Years

Application Areas and Compatible Vehicles/Equipment

Wheel Loaders (Primary Application — Highest Volume)

Wheel loaders are the single largest consumers of hydraulic transmission oil in the construction equipment fleet because they use a combined hydraulic/transmission system that is refilled and topped up more frequently than dedicated systems due to the extremely demanding duty cycle (high-speed shuttle between the pile and the truck, repeated direction changes, frequent gear shifting, continuous hydraulic loading).

• Caterpillar: 906/908/910/914/918/920/924/926/930/938/950/962/966/972/980/986/988/990/992/994 series — using Cat TDTO (Transmission/Drive Train Oil) or equivalent
• Komatsu: WA100/WA200/WA250/WA320/WA380/WA430/WA470/WA500/WA600/WA700/WA800/WA900/WA1200 — using Komatsu KDTF or equivalent
• Volvo CE: L30/L35/L45/L50/L60/L70/L90/L110/L120/L150/L180/L220/L260/L350 — using Volvo transmission oil or equivalent
• Hitachi: ZW series (ZW100/ZW140/ZW180/ZW220/ZW250/ZW310/ZW370)
• Doosan: DL200/DL250/DL300/DL350/DL420/DL450/DL550
• Hyundai: HL series (HL740/HL757/HL760/HL770/HL780)
• John Deere: 344/444/524/544/624/644/724/744/844/944 K/L series
• Case: 21/121/221/321/521/621/721/821/921/1021/1121/1221 series — using Case MAT 3540 or equivalent
• Liebherr: L506/L508/L514/L524/L538/L546/L550/L556/L566/L576/L580/L586
• JCB: 403/410/417/427/432/437/457 series
• SDLG: LG918/LG933/LG936/LG938/LG946/LG948/LG953/LG956/LG958/LG968/LG978
• Liugong: CLG816/CLG820/CLG825/CLG835/CLG842/CLG848/CLG856/CLG862/CLG870/CLG877/CLG886/CLG890/CLG8128
• XCMG: LW156/LW180/LW300/LW400/LW500/LW600/LW700/LW800/LW900/LW1200
• Lonking: CDM816/CDM833/CDM835/CDM855/CDM856/CDM858/CDM860
• Shantui: SL20W/SL30W/SL50W/SL60W
• Chenggong: CG932/CG942/CG948/CG956/CG958/CG966/CG990

Bulldozers — Torque Converter and Powershift Transmission

• Caterpillar: D3/D4/D5/D6/D7/D8/D9/D10/D11 — using Cat TDTO or equivalent
• Komatsu: D21/D31/D37/D39/D51/D61/D65/D85/D155/D275/D375/D475 — using KDTF or equivalent
• John Deere: 450/550/650/700/750/850 series
• Shantui: SD08/SD13/SD16/SD22/SD23/SD32/SD42
• HBXG (Xuangong): TY160/TY220/TY320
• Liugong: B160/B161
• XCMG: TY160/TY230/TY320
• Yishan (Yishan): TY160/TY220

Motor Graders

• Caterpillar: 12M/14M/16M/18M/24M — using Cat TDTO
• John Deere: 622/670/672/770/772/870/872 — using JDM J20C/J20D
• Komatsu: GD355/GD555/GD655/GD675/GD825
• Volvo CE: G900/G930/G940/G946/G960/G970/G976/G990
• XCMG: GR135/GR165/GR180/GR215/GR260/GR300
• Liugong: CLG414/CLG418/CLG425
• SANY: STG170/STG190/STG210
• Shantui: SG16/SG18/SG21

Articulated Dump Trucks

• Volvo: A25/A30/A35/A40/A45/A60 — using Volvo transmission oil
• Caterpillar: 725/730/735/740/745 — using Cat TDTO
• John Deere: 250D/300D/370E/410E/460E
• Bell: B25/B30/B35/B40/B45/B50/B60
• Doosan/Moxy: DA30/DA40/DA45
• Terex: TA250/TA300/TA400
• XCMG: XDA30/XDA40/XDA60

Backhoe Loaders

• Caterpillar: 416/420/426/428/430/432/434/444
• JCB: 3CX/4CX/5CX series
• Case: 580/590 series
• John Deere: 310/410/710 series
• Komatsu: WB91/WB93/WB97 series
• Volvo: BL60/BL70/BL71 series
• Liugong: CLG766/CLG776/CLG777

Agricultural Tractors — Combined Hydraulic/Transmission Systems (UTTO Applications)

Many agricultural tractors use a single fluid for the rear axle, transmission, wet brakes, power take-off (PTO) clutch, and hydraulic system. While the 8# is primarily positioned for construction equipment, it can also serve these agricultural UTTO (Universal Tractor Transmission Oil) applications:

• John Deere: 5/6/7/8/9 series — using JDM J20C/J20D
• Case IH: Maxxum, Puma, Magnum, Optum, Steiger — using MS 1209/MS 1210 (Hy-Tran)
• New Holland: T4/T5/T6/T7/T8/T9 — using MAT 3540 (same as Case)
• AGCO/Massey Ferguson: MF4700/MF5700/MF6700/MF7700/MF8700 — using Permatran III
• Kubota: M series, L series — using Kubota Super UDT/UDT2
• Lovol: P series (P2504, etc.)
• YTO: LX series
• Dongfanghong: Various tractor models

Quarrying and Aggregate Equipment

• Quarry wheel loaders operating in aggregate loading applications
• Mobile screening and crushing plants with hydraulic drives and powershift transmissions
• Conveyor drive systems using hydraulic transmission fluid

Target Customers and B2B Solutions

Construction Equipment Dealers — Highest-Volume Consumable:
The 8# hydraulic transmission oil is the highest-volume consumable product sold by construction equipment dealers serving the wheel loader market. A single wheel loader consumes 50–200 liters per transmission/hydraulic system refill, with change intervals of 1,000–2,000 hours. Dealers serving fleets of 100+ wheel loaders may consume 50,000–100,000+ liters annually of this single product.

Mining and Quarrying Companies:
Wheel loader fleets at mines and quarries work in extremely demanding conditions — high ambient temperatures, heavy dust loads, maximum load cycles, and 24/7 operation. These operations consume hydraulic transmission oil at accelerated rates and require a product that maintains performance under sustained severe conditions.

Road Construction and Earthmoving Contractors:
Companies operating fleets of motor graders, bulldozers, articulated dump trucks, and wheel loaders for road construction, site development, and earthmoving projects require the 8# for scheduled maintenance and system top-ups.

Agricultural Equipment Dealers and Cooperatives:
In markets where agricultural tractors use combined hydraulic/transmission systems, the 8# can serve as the primary fluid recommendation for rear axle, transmission, wet brake, and hydraulic system service.

Bulk Lubricant Distributors:
Distributors specializing in bulk lubricant sales to construction companies, mines, and equipment dealers can include the 8# as a core product in their construction machinery fluid portfolio, alongside the 46# hydraulic oil and GL-5 gear oil.

Why Choose 8# Hydraulic Transmission Oil for Your Business?

1. Multi-Functional Performance — one fluid serves hydraulic, torque converter, transmission, wet brake, and final drive requirements
2. Optimized Clutch Friction — delivers short coupling times, fast gear changes, and smooth powershift operation
3. Excellent Oxidation and Thermal Stability — resists degradation under the severe thermal conditions of torque converter and clutch operation
4. Good Emulsification Resistance — rapidly separates water contamination, maintaining system cleanliness and performance
5. Comprehensive Wear Protection — protects gears, bearings, clutch plates, brake discs, and hydraulic components
6. Reduced Transmission Losses — minimizes parasitic power consumption for better fuel efficiency and productivity
7. Full Seal Compatibility — prevents leaks across the diverse seal materials used in integrated hydraulic/transmission systems
8. Highest-Volume Wheel Loader Consumable — the product that generates the greatest recurring revenue in the wheel loader market
9. OEM-Compatible Formulation — suitable as an alternative to OEM-branded transmission fluids at competitive pricing
10. Available in Bulk — 18L buckets and 208L drums for efficient delivery to construction sites and equipment yards