Can gearbox oil quantity be calculated from center distance and ratio?

Not reliably. Required quantity depends on the exact gearbox,options,mounting position and lubrication arrangement. Use the nameplate,order documentation or manufacturer manual and verify the prescribed level.

Does the calculated difference tell me how much oil to pour into a gearbox?

No. It is arithmetic between two documented quantities. Retained oil,temperature,level-check procedure and the installed position can make a drained or measured amount unsuitable as an inventory of oil inside the gearbox.

Manufacturer-documented quantity — no geometry estimate

Documented Gearbox Oil Quantity Converter

Convert the oil quantity specified for the exact gearbox and mounting position. Optionally compare it with a second documented quantity. This tool does not infer the required fill from ratio,center distance or number of stages.

Document-controlled inputExact unit factorsDifference only—not a fill instruction

Documented quantity conversion

Documented target

—

Target in litres

—

Target in millilitres

—

Target in US liquid gallons

—

Comparison quantity

Not supplied

Signed difference target−comparison

未计算

Difference relative to target

未计算

Arithmetic relation

Target conversion only

Implemented arithmetic

Vtarget,L = convert(documented target)
ΔV = Vtarget,L − Vcomparison,L
relative difference = 100ΔV / Vtarget,L

The sign is exact for parsed decimal inputs and the listed unit factors. Positive ΔV means the comparison number is below the target number;negative means it is above. That relationship is not an instruction to add or remove oil.

Exact unit factors

1L=1000mL exactly. One US liquid gallon is 231in³ and converts to3.785411784L using the current NIST Handbook44—2026 AppendixC values.

Why the geometry estimate was removed

The former page used V≈k(CD/100)^2.5×stages with k chosen only from whether ratio exceeded20. No primary source supported that equation,its coefficients,exponent or the assumption that ratio identifies gear type. It omitted housing geometry,gear immersion,options,mounting position,expansion volume and splash/pressure lubrication.

Manufacturer evidence

NORD service guidance directs users to the nameplate or order confirmation for the required oil type and quantity and warns that changing the version requires the quantity,level points and vent position to be adjusted. NORD technical information TI80_0042 states its table quantities are approximate and that the individual quantity is on the nameplate.

SEW-EURODRIVE Gear Units catalog,23577266/EN—02/2019 likewise labels listed fill quantities as guide values,states that exact values vary with stages and ratio,and requires checking the oil-level plug. It also requires the fill quantity to be adapted when mounting position changes.

No universal lubricant or interval

This page does not prescribe ISO VG220–320,PAG,EP additives or a universal change interval. Lubricant type,viscosity,compatibility,temperature and service interval are gearbox- and duty-specific. Follow the current order documentation,nameplate and manufacturer maintenance procedure. SEW-EURODRIVE’s current filling instructions require the order-specific oil grade and warn against mixing synthetic oils or mixing synthetic and mineral oils.