Welcome to our resource for MG Car Information.



TR parts and Triumph parts, TR bits, Triumph Car Spares and accessories are available for TR2, TR3, TR3A, TR4, TR4A, TR5, TR6, TR7, TR8, Spitfire and Stag and other TR models are available from British car spares and parts company LBCarCo.

Triumph Spitfire - Spitfire 1500 Transmission with overdrive for a MIDGET 1500

Hi All,

I was wondering if I should try to replace the transmission in my 79 MIDGET with a Spitfire 1500 transmission with overdrive. I am considering this because it looks like there is not a good 5 speed conversion for the MIDGET 1500.

How much does the overdrive help? Is it like a 5th gear. My MIDGET really has to rev to get to high speeds like 65-70 MPH.

Thanks in advance for any help.

Also, are some years better than others when it comes to this transmission?

Pat Farrell

Hi Pat,

You must have what is referred to as the single-rail gearbox in your 1500 Midget. It was introduced in mid- to late- 1974. It had the option of J-type Laycock overdrive on 3rd and 4th gears.

I have a '73 that has the earlier type of transmission, and don't have an overdrive unit yet, but I know I need one.

Just be sure to get a single-rail 'box, as the earlier three-rail would need a different crankshaft due to a different size input shaft.

To give you a rough idea of the improvement you get with OD, the Brooklands "Spitfire Gold Portfolio" says that a late Spit is capable of doing 90mph at 4,200 rpm in overdrive 4th.

Hope this helps. Feel free to contact me if you have any other concerns.

Happy motoring,


This thread was discussed between 21/03/2001 and 28/03/2001

Triumph Spitfire index