Product Overview

The G8 Performance Tier GL-5 represents ROCKEFELLER’s premium gear lubrication solution for the most demanding drivetrain applications in the commercial vehicle, construction equipment, and mining industries. Formulated with advanced total synthesis technology, the G8 delivers the extreme-pressure (EP) performance, thermal stability, and wear protection required by modern heavy-duty axles, hypoid gear final drives, and the specialized reduction gearboxes found in excavators, wheel loaders, bulldozers, and other heavy construction machinery.

API GL-5 is the highest performance level in the API gear oil classification system, designed specifically for gears operating under the most severe conditions:

• Hypoid gears with significant sliding contact between tooth surfaces (as found in virtually all modern truck and equipment final drives)
• High-speed/shock-load conditions experienced during highway operation, sudden acceleration, and dynamic loading
• Low-speed/high-torque conditions encountered during grading, excavation, heavy towing, hill climbing, and crawler machine operation
• High-speed/low-torque conditions during sustained highway cruising at moderate loads

The term “hypoid” refers to the offset spiral bevel gear design used in virtually all modern rear axles and many equipment final drives. Unlike conventional spur or straight bevel gears where tooth surfaces primarily roll against each other, hypoid gear teeth experience a combination of rolling and sliding contact. This sliding action generates extreme pressures and temperatures at the tooth surfaces, requiring gear oils with significantly higher EP (extreme pressure) additive content than lower GL classifications. The G8’s GL-5 formulation provides the robust EP protection these gears demand.

For excavators specifically, the gear oil serves a critical role in protecting multiple drivetrain components:

• Swing drive reduction gearbox: The upper structure rotation mechanism that allows the cab and boom to rotate 360°, experiencing frequent direction reversals and high shock loads during digging operations
• Travel drive reduction gearbox: The final drive units in each track that convert hydraulic motor torque into crawler track movement under extremely high loads and low speeds
• Hub reduction axles (wheeled excavators): The planetary gear sets within each wheel hub that provide the final gear reduction for wheeled excavator models

The G8 is manufactured to international quality standards with a five-year shelf life and is available in both 4-liter tins and 18-liter buckets.

Key Functional Features and Performance Benefits

Thermal Stability and Oxidation Resistance

★ Excellent Thermal Stability and High-Temperature Oxidation Resistance — Reduce Carbon Deposits and Extend Gear and Bearing Life:
Gear oil operating temperatures in heavy-duty axles and equipment reduction gearboxes can reach 120–150°C during sustained heavy operation, and even higher during extreme conditions. At these temperatures, inferior gear oils rapidly oxidize, forming:

• Carbon deposits on gear tooth surfaces that interfere with proper tooth meshing and create abrasive particles
• Varnish and lacquer on bearing surfaces and housing walls that restrict oil flow and impair heat dissipation
• Sludge that settles in oil passages and sumps, reducing effective oil volume and contaminating fresh oil charges
• Acidic oxidation byproducts that attack bearing surfaces, seal materials, and housing components

The G8’s advanced synthetic formulation provides exceptional resistance to thermal breakdown and oxidation. The oil maintains its chemical integrity at sustained high temperatures, keeping gear teeth, bearings, and housing surfaces clean and free of harmful deposits. This translates directly into:

• Extended gear life: Clean gear teeth with proper surface finish mesh correctly, distributing loads evenly and avoiding the concentrated stress points that initiate pitting, spalling, and tooth breakage
• Extended bearing life: Clean bearing surfaces maintain proper clearances and oil film conditions, preventing the premature fatigue failure that occurs when bearings operate in contaminated or degraded oil
• Extended oil life: The G8’s oxidation resistance means the oil itself lasts longer, enabling extended drain intervals that reduce maintenance costs and equipment downtime

In excavator applications, this thermal stability is particularly critical because the swing drive and travel drive gearboxes operate in a thermally hostile environment — enclosed within the machine’s lower frame or turntable, adjacent to hydraulic systems generating significant heat, and often with limited cooling airflow. The G8 maintains its protective properties under these sustained high-temperature conditions.

Wear Protection

★ Outstanding Performance in Preventing Low-Speed/High-Torque Wear and High-Speed Scratching:
The G8 delivers dual-mode wear protection engineered for the two distinct failure modes that threaten hypoid gears:

Low-Speed/High-Torque Wear (Scuffing):
When hypoid gears operate at low speeds under heavy loads — as in excavator travel drives during dozing operations, truck axles during hill climbing at low speed, or any heavy equipment final drive during maximum-effort operations — the gear teeth experience extreme contact pressures. Under these conditions, the hydrodynamic oil film that normally separates tooth surfaces becomes too thin to prevent metal-to-metal contact. Without adequate EP protection, the tooth surfaces weld together at microscopic contact points, and the sliding action tears these welds apart, causing progressive surface damage known as scuffing.

The G8’s EP additive system provides a chemically-reactive protective mechanism: at high contact pressures and temperatures, the EP additives react with the metal surfaces to form iron sulfide and iron phosphate boundary films that have low shear strength, preventing welding and allowing the sliding surfaces to move past each other without damage. This protection is especially critical in excavator travel drives, which routinely operate at very low speeds and extremely high torques during excavation, grading, and material handling operations.

High-Speed Scratching (Scoring/Scoring Wear):
During high-speed operation (highway driving, rapid swing or travel at maximum speed), gear teeth experience a different type of wear challenge. The combination of high sliding velocities and elevated temperatures can cause the oil film to break down locally, allowing tooth surfaces to contact and scratch each other. The G8’s formulation maintains film integrity at high speeds and prevents the localized temperature spikes that cause scoring damage.

★ High-Load Capacity — Extreme Pressure Performance for Maximum Protection:
The G8’s high-load capacity — measured by standardized tests such as the FZG gear test, Timken EP test, and four-ball EP test — ensures the oil can withstand the extreme contact pressures generated in heavily loaded hypoid gears and planetary reduction sets. This high-load capacity provides a critical safety margin above normal operating conditions, protecting gears during:

• Shock loading: Sudden impacts when an excavator bucket strikes rock or when a truck encounters a pothole at speed
• Overloading: Conditions where the operator temporarily exceeds the machine’s rated capacity
• Cold-start conditions: When oil viscosity is high and gear teeth must operate without full hydrodynamic lubrication until the oil warms up
• Extended operation at maximum capacity: Continuous heavy digging, maximum gradient towing, or sustained high-speed travel

Corrosion and Rust Protection

★ Excellent Rust and Corrosion Protection — Preserve Component Surfaces and Extend Service Life:
Gear housings, bearings, and gear tooth surfaces are all vulnerable to corrosion from moisture contamination, acidic oil degradation products, and reactive gases. The G8 provides comprehensive corrosion protection through:

• Rust inhibitors: Form protective films on ferrous surfaces (gears, shafts, bearings, housings) that prevent moisture and oxygen from initiating the rust process
• Copper passivators: Protect bronze and copper-alloy components (thrust washers, bushings, synchronizer rings) from the corrosive attack of sulfur-containing EP additives — a critical balance in GL-5 formulation because the EP additives must be chemically reactive enough to protect gear teeth while not attacking softer copper-alloy components
• Acid neutralization: Neutralizes the acidic byproducts of oil oxidation and moisture contamination, preventing acid-driven corrosion of bearing surfaces and housing materials

In excavator applications, moisture contamination is a persistent challenge because these machines operate in wet, muddy, and humid environments. Water can enter gear housings through breather vents, worn seals, and during pressure washing. The G8’s corrosion protection system manages this moisture contamination, preventing the devastating rust and corrosion damage that can destroy expensive gear sets and bearings.

Low-Temperature Performance and Seal Compatibility

★ Effective Low-Temperature Lubrication — Reduced Wear During Cold Starts and Easy Machine Start-Up:
During cold ambient conditions, gear oil viscosity increases dramatically. If the oil becomes too thick, it cannot flow properly to all gear tooth surfaces and bearing locations, causing dry running and accelerated wear during the critical warm-up period. Additionally, excessively thick gear oil creates high churning resistance, which:

• Increases starting torque requirements, making it difficult to start machines and move vehicles
• Increases parasitic drag on the drivetrain, reducing fuel efficiency until the oil warms up
• Can trap air bubbles in the oil, leading to foaming and further degradation of lubrication

The G8’s advanced synthetic base oil technology provides excellent low-temperature fluidity, ensuring:

• Rapid oil distribution to all gear teeth and bearing surfaces during cold starts
• Reduced starting effort and smoother initial operation in cold weather
• Faster warm-up to normal operating temperature due to reduced churning losses
• Better fuel efficiency during the warm-up period

For excavators operating in cold-climate construction projects (pipeline construction, arctic mining, winter road building), the G8’s low-temperature performance is essential for reliable daily start-up and operation.

★ Compatible with Typical Vehicle Oil Seals and Gaskets — Reduce Leakage and Pollution:
The G8 is formulated for full compatibility with the elastomeric seal materials used in axle housings, gear cases, and reduction gearboxes — including Viton (FKM), nitrile (NBR), polyacrylate, and silicone compounds. The oil does not cause excessive swelling, shrinking, hardening, or degradation of these seal materials, maintaining the sealing integrity that prevents oil leaks.

In excavator applications, oil leaks from travel drives and swing drives are particularly problematic because:

• Leaked oil contaminates the ground, creating environmental liability and regulatory compliance issues
• Oil loss reduces the lubricant volume in the gearbox, potentially leading to inadequate lubrication and component failure
• Oil on external surfaces attracts dust and dirt, creating abrasive contamination that accelerates external seal wear
• Visible oil leaks reduce machine resale value and create a negative impression of maintenance quality

The G8’s seal compatibility helps prevent these issues throughout extended service intervals.

Technical Specifications

Parameter	G8 GL-5
API Classification	GL-5
Performance Tier	G8 (Premium)
Base Oil Technology	Advanced Total Synthesis
EP (Extreme Pressure) Rating	High
Thermal Stability	Excellent
Oxidation Resistance	High Temperature
Low-Speed/High-Torque Protection	Outstanding
High-Speed Scratch Prevention	Outstanding
Load Capacity	High
Rust/Corrosion Protection	Excellent
Copper Corrosion Protection	Yes
Low-Temperature Fluidity	Excellent
Seal Compatibility	Full
Carbon Deposit Control	Excellent
Backward Compatibility	GL-4, GL-3, GL-2, GL-1
Available Packaging	4L Tin, 18L Bucket, 208L Drum
Shelf Life	5 Years

Application Areas and Compatible Vehicles/Equipment

Excavators (Primary Specialized Application)

Hydraulic Excavators — Swing Drive and Travel Drive Reduction Gearboxes:
The G8 is the recommended gear lubricant for the critical reduction gearboxes in hydraulic excavators of all sizes:

• Mini Excavators (1–8 ton): Caterpillar 301.5/303.5/305.5; Komatsu PC18/PC30/PC55/PC78; Kubota KX/U series; Yanmar ViO/SV series; Bobcat E20/E35/E50/E85; Takeuchi TB series; SANY SY16/SY26/SY35/SY55/SY75; XCMG XE15/XE35/XE55/XE75; Liugong CLG9035/CLG9055/CLG9075; Doosan DX27/DX35/DX55/DX80
• Medium Excavators (8–30 ton): Caterpillar 320/323/325/330; Komatsu PC130/PC200/PC210/PC228/PC240/PC270/PC300; Volvo EC140/EC200/EC220/EC250/EC300; Hitachi ZX130/ZX200/ZX210/ZX240/ZX270/ZX300; Kobelco SK130/SK200/SK210/SK260/SK300; SANY SY135/SY155/SY195/SY215/SY235/SY265/SY285/SY305; XCMG XE135/XE155/XE200/XE215/XE235/XE265/XE305; Liugong CLG913/CLG915/CLG920/CLG925/CLG930/CLG936; Doosan DX140/DX190/DX225/DX255/DX300; Hyundai HX140/HX220/HX260/HX300; Case CX130/CX210/CX250/CX300; Lonking CDM6150/CDM6225/CDM6240/CDM6285
• Large Excavators (30–100+ ton): Caterpillar 345/349/352/374/390; Komatsu PC350/PC400/PC450/PC490/PC700/PC800/PC1250/PC2000; Volvo EC350/EC380/EC480/EC750; Hitachi ZX350/ZX400/ZX470/ZX520/ZX650/ZX690/ZX870; Kobelco SK350/SK480/SK500/SK850; SANY SY365/SY395/SY465/SY485/SY500/SY750/SY870/SY980; XCMG XE370/XE380/XE470/XE490/XE700/XE900; Liebherr R944/R946/R950/R960/R966/R976/R984/R9100/R9150/R9200/R9250/R9350/R9400/R9800
• Wheeled Excavators: Caterpillar M315/M317/M320; Komatsu PW148/PW160/PW180; Volvo EWR150/EWR170; Doosan DX140W/DX170W/DX190W; Hyundai HW140/HW160/HW210; SANY SY155W/SY210W; XCMG XE150W/XE210W — hub reduction axles require GL-5 gear oil

Heavy-Duty Truck Axles (On-Highway)

Drive Axles and Rear Axles (Hypoid Gear Type):

• Chinese Heavy Trucks: FAW Jiefang J7/J6P/J6L — Hande, FAW, and ATC axles; Dongfeng Tianlong/Tianjin — Dana, Dongfeng, and Hande axles; Sinotruk HOWO A7/T7H/T5G — MC/AC series axles; SHACMAN X6000/X3000/F3000 — Hande axles; Foton Auman EST/GTL — Meritor, Hande axles; Beiben V3/NG80 — North Benz axles; CAMC, JAC, Dayun — various axle suppliers
• European Trucks: Mercedes-Benz Actros/Arocs/Atego — HL/HR series axles; Volvo FH/FM — Volvo RT/RS axles; Scania R/S — Scania RP/RBP axles; MAN TGX/TGS — MAN HY/HP axles; DAF XF/CF — DAF axles; IVECO — IVECO axles; Renault Trucks
• American Trucks: Freightliner, Kenworth, Peterbilt, International, Mack, Volvo VNL — Dana Spicer, Meritor, ArvinMeritor, Eaton axles
• Japanese Trucks: Isuzu, Hino, Mitsubishi Fuso, UD Trucks — OEM axles
• Indian Trucks: Tata, Ashok Leyland, BharatBenz, Eicher, Mahindra — various axle types

Construction Equipment (Beyond Excavators)

Wheel Loaders — Axles and Differential:

• Caterpillar 950/962/966/972/980/988/990/992/994; Komatsu WA380/WA430/WA470/WA500/WA600/WA700/WA800/WA900/WA1200; Volvo L60/L90/L110/L120/L150/L180/L220/L260/L350; SDLG LG936/LG953/LG956/LG958/LG968; Liugong CLG835/CLG842/CLG856/CLG862/CLG870/CLG886/CLG8128; XCMG LW300/LW500/LW600/LW800/LW900/LW1200; Lonking CDM835/CDM855/CDM856/CDM858; Doosan DL250/DL300/DL420/DL550
• GL-5 gear oil serves the front and rear axle differentials, planetary hub reductions, and transfer case (where fitted)

Bulldozers — Final Drive Reduction Gearboxes:

• Caterpillar D3/D4/D5/D6/D7/D8/D9/D10/D11; Komatsu D31/D37/D39/D51/D61/D65/D85/D155/D275/D375/D475; Shantui SD08/SD13/SD16/SD22/SD23/SD32/SD42; HBXG TY160/TY220/TY320; Liugong B160/B161; XCMG TY160/TY230/TY320
• The final drive planetary reduction sets on each side of the undercarriage require GL-5 gear oil

Motor Graders — Tandem Drive Cases and Axles:

• Caterpillar 12M/14M/16M/18M/24M; Komatsu GD555/GD655/GD675; XCMG GR135/GR165/GR180/GR215/GR260/GR300; Liugong CLG414/CLG418/CLG425; SANY STG170/STG190/STG210; Shantui SG16/SG18/SG21

Drilling Rigs and Piling Equipment — Rotary Gearboxes:

• Rotary drilling rigs (SANY SR150/SR200/SR250/SR360/SR400; XCMG XR150/XR220/XR280/XR360/XR460; Bauer BG; Liebherr LB; Casagrande) — the rotary gearbox requires GL-5 gear oil

Commercial Vehicles — Axles and Manual Transmissions

Light and Medium-Duty Commercial Vehicles:

• Pickup trucks (Toyota Hilux, Nissan Navara, Ford Ranger, Isuzu D-Max, Mitsubishi L200) — rear differential
• Vans (Mercedes-Benz Sprinter, VW Crafter, Ford Transit, Iveco Daily) — rear differential
• Medium trucks (Isuzu Forward/FTR, Hino Ranger, Mitsubishi Fuso Fighter) — rear axle and transfer case (4WD models)

Buses and Coaches:

• Drive axle differentials and hub reductions on all bus and coach platforms requiring GL-5 gear oil

Mining Equipment

• Haul Trucks: Caterpillar 773/777/785/789/793/797; Komatsu HD605/HD785/HD985/HD1500; BelAZ 7513/7555/7571; Terex TR60/TR70/TR100; XCMG XDE110/XDE130/XDE200/XDE240; SANY SKT90S/SKT105S — final drive planetary reductions and differential assemblies
• Underground LHD (Load-Haul-Dump): Caterpillar R1700/R2900/R3000; Sandvik LH410/LH514/LH517/LH621; Epiroc ST14/ST18; XCMG — axle and differential lubrication

Agricultural Equipment

• Tractor Axles and Final Drives: Particularly for tractors with separate gear oil-lubricated axles (not shared with hydraulic/transmission oil)
• Self-Propelled Equipment: Front and rear axle differentials on self-propelled sprayers, forage harvesters, and combine harvesters

Target Customers and B2B Solutions

Excavator Fleet Operators and Rental Companies:
Companies operating fleets of excavators — construction contractors, demolition companies, landscaping companies, quarrying operators, and excavator rental companies — consume significant volumes of GL-5 gear oil for swing drive and travel drive gearbox maintenance. The G8 provides OEM-grade protection at competitive pricing, with the convenience of a single GL-5 product serving all excavator brands and sizes in the fleet.

Heavy-Duty Truck Fleet Operators:
Trucking companies and logistics providers maintaining large fleets of commercial vehicles require reliable GL-5 gear oil for scheduled axle and transmission maintenance. The G8 serves this need with consistent quality and competitive bulk pricing.

Construction Equipment Distributors and Service Providers:
Companies distributing construction equipment parts and consumables, as well as independent repair shops specializing in excavator and heavy equipment service, can stock the G8 as their primary GL-5 gear oil recommendation.

Mining Operations:
Mining companies operating large fleets of haul trucks, excavators, loaders, and underground equipment require GL-5 gear oil in significant volumes for final drive, axle, and differential maintenance.

OEM Service Networks:
Authorized dealers and service centers for major equipment brands (Caterpillar, Komatsu, Volvo CE, SANY, XCMG, Hitachi, Kobelco, etc.) can adopt the G8 as their service-fill GL-5 gear oil, particularly in emerging markets where OEM-branded products carry significant price premiums.

Why Choose G8 GL-5 for Your Business?

1. API GL-5 Certified — meets the highest gear oil performance classification for maximum protection of hypoid gears under extreme loads
2. Advanced Total Synthesis Technology — superior thermal stability and oxidation resistance compared to conventional mineral gear oils
3. Dual-Mode Wear Protection — outstanding performance against both low-speed/high-torque scuffing and high-speed scratching
4. Excavator-Optimized — specifically proven for the demanding swing drive and travel drive gearbox applications
5. Excellent Low-Temperature Fluidity — ensures reliable cold-start protection and reduced warm-up losses
6. Full Seal Compatibility — prevents leaks that cause environmental contamination and component damage
7. High-Load Capacity — provides critical safety margin above normal operating conditions for shock loads and overloading
8. Comprehensive Corrosion Protection — guards against moisture contamination common in construction and mining environments
9. Extended Drain Capability — reduces maintenance frequency for improved equipment availability and lower total cost
10. Universal GL-5 Applicability — one product serves excavators, truck axles, construction equipment drives, and all other GL-5 applications