The BC-series manual transmissions are a range of manual transaxles produced by Ford in Europe for its front-wheel-drive automobiles from 1976 onwards. Originally debuting in the Mk.1 Ford Fiesta, the unit was later used in Ford's other front-wheel-drive vehicles, most notably the Ford Escort and Orion.
The unit features a 20mm x 17 spline input shaft, uses a rod-based shift linkage and was originally only available in 4-speed format, designated as BC4, and designed to mate either with the Valencia version of the OHV Ford Kent engine, or the CVH unit. The 5-speed BC5 version appeared in 1982 on the Escort as a standard fitment on 1.6 litre cars, and as an option on 1.3 models, and became available on the Fiesta Mk2 in 1983.
A completely revised version of the transaxle was introduced in 1995 and was designated iB5, and was initially introduced for the Mk.4 Fiesta. The major difference being an improved cable-operated shift mechanism and the introduction of a hydraulically operated clutch. The ultimate version is IB5+, manufactured only in Brazil, that fits engines as big as 2.0 litre.