MGA Gearbox Conversion Kit 5 Speed Mazda


Prices are exclusive of VAT

Available - Despatched 1-2 business days after order receipt
Product code VITMGA255

Vitesse Gearbox Conversion kit, designed to perfectly replace your existing MGA gearbox, using the proven Mazda MX-5 Mk3 5 Speed Transmission.

MGA gearbox fitting service available.

Due to the variations in the traditional MGA multi coil spring clutch, we now include a new diaphragm spring clutch cover assembly in all MGA 1500 and 1600 kits.

Our MGA gearbox 1500 kit includes a new aluminium backplate and the Twin Cam / Deluxe kit includes a new clutch master cylinder.

"With lifting equipment, the easiest way to fit our MGA new 5-speed replacement gearbox kit is to remove the old gearbox with the engine. Should the floorboards have been removed in the last 10 years, an alternative way is via the cockpit, leaving the engine in-situ.

Any competent Fitter can undertake this work. If your kit does not fit easily we suggest you seek professional help. Remember all MGA’s are in the region of 60 years old. It is not necessary to bodge your pride and joy to fit our kit."

Alec Poole, Vitesse Ltd Sales Manager, Sixties MG Engineering Apprentice and Works Race Driver

Suitable for all MGAs, including 1800 conversions.

Now with a gear knob that perfectly complements your vehicle's interior.






Our kit includes the following:

  • NEW Mazda MX-5 5 Speed Transmission:
    • Vitesse Gearbox Case
    • Vitesse Bellhousing
    • Vitesse Machined Billet Front Plate
    • Modified rear case with Mazda mechanical Speedo Drive Assembly
  • Mazda MX-5 OE Clutch Friction Plate
  • Bespoke Shift Lever and Shift Knob kept in original position
  • Concentric Slave Cylinder Assembly
  • Braided Clutch Pipe and remote Bleed Pipe for easy bleeding
  • Prop Shaft
  • Spigot Bush with Mazda OE needle roller bearing assembly
  • Speedo Drive Cable
  • Gearbox Rear Mount Bracket Assembly and Isolator
  • Complete UNF fixings kit
  • Clutch Alignment Tool


The gearbox comes fully assembled including the clutch slave cylinder assembly so the fitting is only as complicated as replacing an original gearbox. We even include a Mazda clutch alignment tool to assist with assembly!

We use all OE Mazda components where possible, ensuring parts quality and also serviceability.

All brackets are electrocoated ensuring maximum resistance to corrosion.


The all alloy case means significant weight savings can be achieved with this kit, up to 13.5kg compared to the MGB Overdrive box! 

MGA gearbox kit weights

Gear Ratios: 

Gear Ratio - Mazda Transmission 
1 3.136
2 1.888
3 1.330
4 1.000
5 0.814


The standard MGA differential has a ratio of 4.1:1, similar to the MX-5 differential, so the gear ratios work perfectly in the MG. Furthermore, the standard gear ratios of the Mazda gearbox are similar to the Ford Type 9 close ratio gear set, which attracts a significant premium over the standard Ford Type 9 gearbox!


12 months manufacturing defect warranty offered on all parts.

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