Transmission & Gear
Gear oil fails differently from engine oil. It is not oxidation that kills a differential but shock loading — the moment a loaded axle takes a hit and the film between two…
Formulated to meet
API CI-4/SLACEA E7API SLAPI GL-5API GL-4ISO VG 10 / 46 / 68DOT 4ASTM D3306 & BS 658001 / Overview
Gear oil fails differently from engine oil. It is not oxidation that kills a differential but shock loading — the moment a loaded axle takes a hit and the film between two tooth flanks has to survive it.
The range covers API GL-5 for hypoid axles, in SAE 85W-140 and a monograde SAE 140, and API GL-4 for manual gearboxes and axles, in SAE 85W-90 and a monograde SAE 90. Four-litre bottles for workshops, twenty-litre pails for fleets. We do not currently carry automatic transmission fluid or a universal tractor fluid.
Every batch is released by AG Lubricants FZE against a certificate of analysis, with a retained sample kept on file so any pack in the field can be traced back. How it is tested
02 / The range
Transmission & Gear
High-performance extreme-pressure (EP) gear oil formulated from high-quality base oils and advanced additives to provide outstanding load-carrying capacity, excellent wear, rust and corrosion protection, ensuring smooth gear operation and extended service life.
Transmission & Gear
Heavy-duty gear oil manufactured from high-quality base oils and high levels of extreme-pressure additives to provide outstanding wear protection. Recommended for a wide variety of manual gear applications including synchroniser-fitted passenger and commercial vehicles.
Transmission & Gear
Premium-quality extreme-pressure (EP) gear oil formulated from high-quality base oils and advanced additives to provide outstanding load-carrying capacity in gear applications where API GL-4 performance is required. Excellent protection against wear, rust and corrosion.
Transmission & Gear
Automotive gear oil for applications where the OEM specifies API GL-5 performance. Silicate and phosphate free with long-life protection, giving excellent wear and load protection, superior oxidation and thermal stability, and smooth gear operation.
03 / Questions
GL-5 carries far more extreme-pressure additive, which is what a hypoid differential needs. That same sulphur-phosphorus chemistry can attack the yellow metals in some synchromesh gearboxes, so where a manual box specifies GL-4, do not substitute a GL-5 on the assumption that more is better.
Use the lighter grade unless the builder allows heavier. Ours are SAE 85W-90 and SAE 90, both API GL-4; where a builder specifies 80W-90, confirm 85W-90 is acceptable before substituting, because the cold-end number differs. Step up to 85W-140 to API GL-5 for heavily loaded truck and trailer axles, off-highway final drives, and axles that run hot for hours on gradients. Too heavy a gear oil costs fuel and slows cold-morning engagement.
No. Automatic transmissions need a friction-controlled fluid so the clutch packs engage predictably. Gear oil in an automatic will cause harsh or slipping shifts and damage the unit.
Universal Tractor Transmission Oil serves a tractor's transmission, final drive, wet brakes and hydraulics from one fluid. It is worth using because it removes the risk of putting the wrong fluid in the wrong port, and because wet brakes chatter badly on an oil that is not friction-matched to them.
04 / Before you buy
How to read an API or ACEA performance level, and which part of it your machine actually needs.
Read the handbook first, then the label. What actually decides the grade for a vehicle working here.
05 / Other families
Send us the machines you run and the volumes you need. Our technical team will confirm the grade, the pack size and an indicative price — usually within one working day.
