Reconditioned SEAT Altea Gearbox

BGU, BSE, CAYC, BKD… which engine code takes which gearbox on the Altea?

On the Altea (2004–2015), it is the engine code stamped on the block — not the engine capacity shown on the spec sheet — that determines the compatible gearbox. A 1.6 petrol can carry the codes BGU, BSE or BSF, all three paired with a 5-speed manual, but the bell housings and shafts differ depending on the code. The 1.6 TDI code CAYC is the only diesel in the range to be offered with either a 5-speed manual or a DSG 6 or DSG 7: three distinct architectures behind a single code, which makes reading the original gearbox reference absolutely essential. The two 2.0 TDI variants share the codes BKD and CFHC, both paired with a 6-speed manual, but these two codes belong to different engine generations and their gearboxes are not interchangeable references. The 1.4 TSI code CAXC is fitted exclusively with a 6-speed manual.

DSG on the Altea 1.6 TDI: what the reference must specify

The presence of a DSG 6 or DSG 7 behind the CAYC is not a trivial detail: both dual-clutch gearboxes are sold with a new dual clutch, without mechatronic unit. The exact DSG generation — 6 or 7 speeds — is read from the plate on the original gearbox, not from the engine code. Confusing the two results in incompatible mounting and control interfaces. For the 5- and 6-speed manuals fitted to the other Altea engines, the main risk is ordering a gearbox with the correct number of ratios but with a final drive ratio that does not suit the vehicle's specification.

Diesel and petrol: two transmission logics on the Altea

The Altea's petrol engines (BGU, BSE, BSF on the 1.6; CAXC on the 1.4 TSI) are paired exclusively with manual gearboxes. On the diesel side, the 2.0 TDI also remains manual, whereas the 1.6 TDI CAYC is the only diesel engine in the Altea range to have been offered with a dual-clutch gearbox. If your diesel Altea is fitted with an automated gearbox, it is therefore necessarily a 1.6 TDI — a useful point when the engine label is illegible or missing.