BMW i4 gearbox: on this fully electric saloon, the term refers in practice to a single-speed transmission — known as a single-ratio drive — that connects the electric motor or motors to the wheels. On sale since 2021 and positioned as a direct rival to the Tesla Model 3, the i4 relies on a simplified drivetrain that nonetheless demands rigorous maintenance. In this guide, EDEN BOITES shares professional techniques to keep your i4's transmission in top condition and explains how to have it repaired.
Understanding the single-speed transmission of the BMW i4
The BMW i4 is fitted with a 1-speed automatic gearbox. Where a combustion transmission multiplies ratios, an electric motor delivers its torque across the entire rev range: a single ratio is therefore sufficient to manage all speeds. A member of the 4 Series family, the i4 is available in several versions:
- i4 eDrive35 with 286 hp: 210 kW sent to the rear axle, 0–100 km/h in 6 seconds.
- i4 eDrive40 with 340 hp: 250 kW, top speed of 190 km/h, 0–100 km/h in 5.7 seconds.
- i4 M50 with 544 hp: all-wheel drive, 400 kW combined, 0–100 km/h in 3.9 seconds and a top speed of 225 km/h.
The 2024 i4 xDrive40 builds on the eDrive40 platform by adding a second electric motor to deliver all-wheel drive.
Our professional techniques for maintaining the i4's gearbox
Don't believe anyone who claims that an electric automatic transmission requires no maintenance. Even in its simplified form, it is subject to wear and can suffer from misuse. A few good habits will extend its service life:
- follow the transmission fluid change intervals recommended by the manufacturer;
- check the level and condition of the gearbox oil regularly: a black colour or a suspicious smell should raise the alarm;
- maintain the cooling system, which is essential on an electric vehicle where the power electronics generate significant heat;
- only engage drive mode changes when the vehicle is at a complete standstill;
- limit towing of heavy loads and, when towing is necessary, follow the instructions in the owner's manual.
An annual transmission service is a useful complement to these good practices. To better understand the mechanical causes of a stubborn gearbox, read our article why is my gearbox stiff.
Repairing the transmission of a BMW i4: the steps
Despite your best efforts, the transmission may show signs of failure. Wheel spin indicates that the motor's power is no longer being correctly transferred to the wheels; a sudden jolt or a locked transmission should also give cause for concern. This electromechanical system requires specialist expertise: at the first sign of abnormal behaviour, contact your mechanic.
The professional will typically proceed as follows:
- reading fault codes with a diagnostic scanner;
- pressure tests or full disassembly of the gearbox if required;
- replacement of faulty components (sensors, seals, solenoids);
- draining and replacing the transmission oil and adjusting pressure;
- replacing the transmission when wear is too advanced.
Do you drive another electrified model from the brand? Also discover our advice for the BMW i8 gearbox and for the BMW i3 gearbox.
Frequently asked questions
Does the BMW i4 actually have a gearbox?
It has a single-speed automatic transmission. There is no gear changing as on a combustion model, but a mechanical reduction unit that transfers torque from the electric motor to the wheels.
Does the i4's transmission need an oil change?
Yes. Even with a single ratio, the transmission contains oil that lubricates the gears. Replacing it at the intervals recommended by the manufacturer preserves the reliability of the whole unit.
Why does my i4 spin its wheels under acceleration?
Wheel spin indicates that power is no longer being correctly transferred to the wheels. The cause may be low oil pressure or internal wear: an electronic diagnostic is essential.
Can the i4's transmission be replaced with a reconditioned unit?
Yes. The exchange basis allows you to fit a fully reconditioned and tested transmission — an economical and environmentally friendly alternative to a new part.
Why choose EDEN BOITES?
EDEN BOITES reconditions its transmissions on an exchange basis: every unit is stripped, inspected and tested before sale. You benefit from a warranty of up to 24 months and a satisfaction-or-refund guarantee on exchange units, subject to our Terms and Conditions. Payment can be spread over several instalments, in up to 10 instalments, and delivery covers France and the European Union, with lead times confirmed on quote. Browse our BMW gearbox catalogue or our full range of gearboxes to find the right reference for your i4.
