Information to Confirm When Sourcing Transmission Gears

The Short Answer

To source a transmission gear, you need to confirm three things: what it fits (the gearbox model or OEM part number), what it is (gear specifications such as tooth count and module), and what you need (quantity, destination, delivery date). Without the first two, no supplier can reliably identify the part.

Transmission gears are application-specific components. Two gears that look similar can differ in tooth profile, helix angle, or heat treatment — differences that only reference numbers and specifications can settle.

Fitment Information: Model and Part Number

The fastest identification path is the OEM part number plus the vehicle and gearbox model it serves. If the part number is unknown or worn off, the gearbox model designation and the gear's position in the transmission (which shaft, which speed) allow identification by comparison.

Photos of the actual part — tooth side, bore side, and any markings — are valuable supporting evidence, especially for older transmissions where documentation is scarce.

• OEM part number, where available.
• Vehicle model and gearbox model designation.
• The gear's position in the transmission.
• Photos and markings from the physical part as backup.

Gear Specifications to Provide

Where you can measure or where drawings exist, provide the gear's technical data: tooth count, module or diametral pitch, helix angle for helical gears, pressure angle where known, bore diameter, and overall dimensions. Any spline data on the bore matters for fitment.

Material and heat-treatment requirements — for example case hardening — affect durability and are specified per part. If you only have the old part, a sourcing partner can coordinate measurement and identification against the sample.

Commercial Information

Quantity changes the sourcing approach: single repair pieces, workshop batches, and distribution volumes are sourced differently. State your quantity honestly — a one-off repair gear and a recurring stock order lead to different supply arrangements.

Destination country and required delivery date determine freight method and whether the timeline is feasible. For repair scenarios where a vehicle is off the road, say so — urgency affects which supply route is proposed.

What Is Verified Per Order

Fitment confirmation, material and heat-treatment details, available quality documents, price, and lead time are all confirmed per order before production or shipment. Where the supplying factory can provide inspection or material documents, a sourcing partner coordinates them with the order.

For first orders of a given part number, receiving a sample or starting with a small batch is a prudent way to verify fitment before committing to volume. This approach is worth discussing at the inquiry stage.