Nine Questions to Ask Before Buying a Used Gearbox

A gearbox is the second most expensive thing you will buy from a breaker, and unlike an engine it gives you very little visual warning that something is wrong. You cannot see wear inside a casing. So the protection is in the questions you ask, not in the photographs you look at.

1. What is the gearbox code?

Same principle as an engine code: the gearbox code is the only reliable identifier. The same car, in the same year, with the same engine can carry different gearboxes depending on drivetrain and trim. Get the code in writing before you pay, and check it against your own. If you cannot find yours, send your registration.

2. What was the donor vehicle, and what happened to it?

Mileage matters, but the reason for scrapping matters more. A rear-end shunt tells you nothing bad about the gearbox. A fire, a flood, or a car scrapped because the transmission failed tells you a great deal. Ask directly.

3. Has it been turned over or tested?

Some sellers bench test, some turn the input shaft by hand and check the box selects through the gears, and some do neither. None of those is automatically wrong — but you should know which one you are buying. A supplier who answers this precisely is a supplier who inspected the unit.

4. What does the oil look like?

Ask for a photo of the drained oil, or at least a description. Metallic glitter suggests internal wear. A burnt smell on an automatic suggests overheating. Clean oil proves nothing on its own, but bad oil is one of the few genuinely reliable warnings you can get from outside a sealed casing.

5. What is included?

Clutch, flywheel, slave cylinder, mounts, selector linkage — on a manual, none of these can be assumed. On an automatic, ask specifically about the torque converter, and on modern units the valve body and mechatronic unit. Assume anything not stated and not photographed is not in the box.

6. Automatic, DSG or CVT?

These are not simply “automatics”. Dual-clutch and CVT units are more expensive, more model-specific and more sensitive to being paired with the wrong control software. If yours is one of these, say so early — it changes what will fit.

7. What is the warranty, and what does it actually cover?

Ask for the length, what voids it, and crucially who pays return freight if the unit is faulty. On a domestic sale that is an inconvenience. On an export order the return cost can exceed the value of the gearbox, which is why a guarantee matters more the further the part is travelling.

8. How will it be packed?

Fluids drained, the unit palletised or crated, openings blanked so nothing gets in during transit. A gearbox that arrives with a cracked bellhousing because it was shipped loose is nobody’s idea of a bargain.

9. Would the matched engine be cheaper?

If the donor’s engine is still available, buying both is often cheaper than sourcing them separately and removes all pairing risk. For volume buyers, a half cut takes the same logic further and brings the loom and ancillaries with it. Browse our current used gearboxes, or send us your code and we will check stock.