8 Weird Gearboxes That Defy Convention

Hyundai iMT

Serving as inspiration for our list, Hyundai recently revealed a new version of its ‘intelligent Manual Transmission’ or ‘iMT’. This gearbox normally uses a by-wire-operated clutch that disengages the engine when you’re coasting, but in the Indian-market Kappa, the iMT does away with the clutch pedal entirely.

Each time the driver shifts, an ‘Intention Sensor’ triggers a hydraulic actuator. An increase in hydraulic pressure then operates the slave cylinder, in turn controlling the clutch and pressure plate. Hey presto, the clutch engages and disengages at just the right moment.

Hyundai dubbed this an “industry first,” but there have been similar systems before, and some other downright weird transmissions.

Alfa Romeo Q System

Already offering certain versions of its gorgeous 156 with an optional (and not especially good) robotised manual five-speed ‘Selespeed’ gearbox, Alfa Romeo clearly thought more transmission weirdness was needed. And so, the 2.5-litre V6 derivative of the car could be specced with something called ‘Q-system’.

This four-speed automatic operates like any other when left to its own devices, but flop the selector over to the left-hand side, and it’s possible to row through the ratios in a traditional manual H-pattern.

Toyota GR HV

Want to know something interesting about the Q-System? It was supplied by Japanese company Aisin, which is majority-owned by Toyota. Perhaps Toyota rolling out the GR HV concept years later with a similar gearbox concept is related.

The GT86 upon which the GR HV is based uses an Aisin automatic gearbox, and low and behold, the 2017 Tokyo Motor Show concept had a slushbox that could be shifted in an H-pattern. It goes one better than Q-System (well, two better) with six ratios instead of four, which can be played with in manual style after a button under a flap on the gear knob is pressed.

VW Autostick

VW had something like Hyundai’s two-pedal iMT way back in 1968. First used on the Beetle and Karmann Ghia, ‘Autostick’ was in production for eight years. The three-speed system works via a button on top of the gear knob which is pressed by the driver’s hand when they go for a shift. The button triggers a 12-volt solenoid which then operates a vacuum clutch. When the driver takes their hand away again, the clutch re-engages.

Saab Sensonic

Arriving several decades later, Saab’s crack at the two-pedal manual took advantage of technology advances for a more sophisticated take on the niche transmission genre. A microprocessor senses when the shift is about to happen, triggering an electronic motor to actuate the master cylinder at the key moment.

It wasn’t a popular option, and it didn’t stay around long - Sensonic had only been available for a few years when it was killed off in 1998.

Abarth 695 Biposto 'dog ring' gearbox

The already hilariously expensive Abarth 695 Biposto had an optional ‘dog-ring’ gearbox costing £8500. We can see why buyers might want to have specced it, though - it’s a racing gearbox lifted straight from the 695 Assetto Corse racing car. Oh, and the exposed lever is a thing of beauty.

It does without the synchromesh you’d find in most transmissions - instead, each cog has a series of ‘teeth’ allowing the gears to ‘bite’ together. It’s not the smoothest way to swap cogs, as you might imagine, but it can be sensationally quick. Although the Biposto still has a clutch pedal which still needs to be used most of the time, if the engine speed is right, it’s possible to bang the next gear in without dipping the clutch at all.

Honda i-MMD

Since it could be described as having no gearbox at all, you might wonder why Honda’s snappily-named Intelligent Multi-Mode Drive hybrid powertrain is here at all. But in a sense, it does.

At lower speeds, a 181bhp electric motor powers the wheels, draining a 1kWh battery which is then topped up by an inline-four acting as a generator. At higher speeds, this petrol engine then powers the wheels via a locked up clutch and a single gear. So in a way, it’s just like a Koenigsegg Regera…

If you think the dual-clutch only setup of the C8 Chevrolet Corvette is eyebrow-raising, just pause for a moment and consider this example of transmission weirdness from the C4 era. The optional ‘Doug Nash’ (named after the hot-rodder) 4+3 gearbox is a four-speed manual, but with an overdrive unit attached to the transmission’s output shaft.

The overdrive is available in second, third and fourth - hence the ‘4+3’ designation - and activated via a button on top of the gear knob. This is all in the name of efficiency, which was vital at a time when sports car makers were struggling to come to terms with tightening emissions regulations in the USA.

It’s a fantastically complex setup under the skin, and if you have a quick Google, you see lots of complaints from owners about the transmissions going wrong. It was part of the C4 range for four years until Chevrolet replaced it in 1988 in favour of a regular six-speed manual.

What other odd gearboxes can you think of?