Buy 85W-90 Gear Oil

85W-90 is an axle oil for heavy duty: robust, load-bearing at high temperatures and correspondingly stiff on a cold start. You find it in truck axles, farm machinery and trailer axles, often with API GL-5 for hypoid gearing.

Where it is used

The difference from 80W-90 and 75W-90 lies in the cold behaviour: 85W is stiffer, which is less of a nuisance in a final drive than in a manual gearbox - there are no synchroniser rings to move there. At operating temperature all three behave much the same.

The grade is typical in:

  • final drives of trucks, trailers and semi-trailers
  • farm machinery and construction vehicles with their own axle specifications
  • applications in warm regions, where cold behaviour plays no part

GL-5 and limited-slip differentials

For hypoid axles, API GL-5 is the usual requirement: a high share of sulphur-based extreme-pressure additives so that the tooth flanks carry the load. This oil has no place in a manual gearbox with brass or bronze synchroniser rings - there the manufacturers require GL-4, see 75W-80.

Axles with a limited-slip differential also need an LS additive, otherwise the diff judders. In the commercial vehicle world, the axle makers' approvals come on top; in commercial use they are a condition, not a recommendation.

Quantities and pack sizes

Final drives take 1 to 3 litres depending on the vehicle, truck axles considerably more. Accordingly, 1-litre bottles suit a single change, and canisters or drums the workshop and the fleet. Larger quantities on request.

We take back waste oil up to the quantity purchased (waste oil disposal); gear oil is expressly included.

Frequently asked questions

Is 85W-90 the same as 80W-90?

At operating temperature they are practically identical; 85W-90 is stiffer on a cold start. Whether you may swap them is decided by the API category and the axle manufacturer's approval, not by how close the numbers look - 80W-90 is the more widespread of the two.

Can I put 85W-90 in a manual gearbox?

Only if the manufacturer names it, and then with the required API category. A GL-5 oil in a gearbox with brass or bronze synchroniser rings can attack the rings over time.

How often is axle oil changed on a commercial vehicle?

According to the maintenance schedule, often by operating hours, mileage or annually - unlike passenger cars, where the axle fill is usually declared a lifetime fill. On trailer and semi-trailer axles the change is part of routine maintenance.