The Mk1, Mk2 and Mk2.5 MX5 was fitted with a number of different differentials, the type of differential AND the finnal drive ratios vary according to model, gearbox and market the car was sold in.

Differential Types

There were two types of differentials fitted to MX5s built between 1989 and 2005. These are:


  • Open Differential
  • Limited Slip Differential - LSD


As a general rule, imported cars had limited slip differentials except automatics which always have open differentials.

Limited Slip Differentials - LSDs

The MX5 (1989 to 2005) had three types of limited slip differentials fitted. These were:

  • Viscous
  • Torsen Type 1
  • Torsen Type 2

Final Drive or Differential Ratios

The final drive or differential ratio will depend on the market the car was originally sold in and the model of the car.


The ratios range from:

  • 3.636:1
  • 3.909:1
  • 4.100:1
  • 4.300:1

The ratio tells you how many times the prop shaft has to go around to turn one revolution of the wheels. So the highest gearing is the 3.6:1 ratio, a nice differential for the motorway.


The Crownwheel and Pinion determine the differential or final drive ratio.

This is a 4100:1 Crownwheel and Pinion.


You can change Crownwheels and Pinions (providing they match) between MX5 differentials (not 1.6 Mk1) but it takes skill and some time to set these up properly.

How do the LSD Actually Work

Viscous Differential - 1.6 Mk1 Cars Only


A viscous differential contains a silicone fluid. When a wheel spins, the fluid in the spiining side gets thicker and causes the transfer of motion to the other side.

Torsen Type Differentials


Torsen differentials provide lockability in a more mechanical way.


Type 1 or Type A - uses crossed axis helical gears to transfer torque across axle

Type 2 or Type B - uses parallel helical gears to do the same thing

4.655:1 Ratio

You can fit a 4.655:1 ratio crownwheel and pinion to a MX5 differential. We undertake this specialist work. This differential ratio is beneficial to those who require additional performance but it is produced for motorsport application only. Click here for more information.

Pictures coming soon

Call us today: 01489 896907



How to Find Us:

Workshop and Office

Unit 12, Woodmans Farm.

Curdridge Lane, Near Waltham Chase, Southampton. Hampshire SO32 2BH


My Three Words - ///loaders.spearhead.plenty

Contact us NOW:

If you have any queries or wish to make an appointment, please call us:


01489 896907


Or use our contact form.


We are open from 10:00 until 17:00 weekdays and 10:30 until 14:30 Saturdays.

Print | Sitemap
Copyright 2015 - DoctorMX5