Triumph Spitfire Overdrive Conversion

Triumph Spitfire Overdrive Conversion

Author
Discussion

peterjfox

Original Poster:

17 posts

46 months

Friday 26th February 2021
quotequote all
Anyone had a 1500 Spitfire Overdrive conversion recently?
Any idea of price recommendations?
Thanks

Spitfire2

1,933 posts

193 months

Saturday 27th February 2021
quotequote all
The price of exchange boxes and overdrive units has gone up a lot in recent years so I expect converting from a regular 4 speed will be a hefty price.

Might be looking for an exchange gearbox for mine soon as I've chipped a tooth in first. Although 2 gearboxes ago I lived with the same first gear tapping away for about 6 years .......

Yertis

18,652 posts

273 months

Sunday 28th February 2021
quotequote all
There’s the electrical side to consider too. I think if I was in your shoes I’d be exploring the five-speed ‘box alternatives, for simplicity and longevity.

hilly10

7,306 posts

235 months

Sunday 28th February 2021
quotequote all
Yertis said:
There’s the electrical side to consider too. I think if I was in your shoes I’d be exploring the five-speed ‘box alternatives, for simplicity and longevity.
Ditto that’s what I would do

//j17

4,612 posts

230 months

Monday 1st March 2021
quotequote all
A lot depends on if you can find a conversion kit/cheap 1500 O/D gearbox on eBay, etc.

None online at the moment but the £2,300 cost of a Frontline 5 speed kit gives you a good budget for a second hand box + other bits (rear mount, prop., Speedo cable and angle drive, some wire).

And with a 1500 Spitfire you're talking about a J-Type overdrive so the electrics are simple.

tapkaJohnD

1,992 posts

211 months

Monday 1st March 2021
quotequote all
Similar thread here, two years ago, found that Mike Papworth was the man to talk to: https://www.pistonheads.com/gassing/topic.asp?h=0&...

The other gearbox guru is Tony Lindsey-Dean. Bioth are so busy and sought-after that they don't bother with a website, but Mike's contac is on that other thread, and Tony appears on Facebook.

John

caziques

2,651 posts

175 months

Saturday 6th March 2021
quotequote all

In 1975, Triumph switched to single rail gearboxes for the Spitfire 1500 and Dolomite 1300/1500/1850.

Making an overdrive version of the single rail box was quite complex, there are all sorts of different parts, whereas a three rail gearbox is relatively straightforward to convert to overdrive.

A car fitted with overdrive is so much better than one without.

It looks like the three rail overdrive adaptor plate (part number 313085) is still available - a D or J type overdrive can use this plate.

//j17

4,612 posts

230 months

Tuesday 9th March 2021
quotequote all
caziques said:
Making an overdrive version of the single rail box was quite complex, there are all sorts of different parts, whereas a three rail gearbox is relatively straightforward to convert to overdrive.
...
It looks like the three rail overdrive adaptor plate (part number 313085) is still available - a D or J type overdrive can use this plate.
Umm, it's no more or less complicated to convert either a single or three rail gearbox to overdrive - but it's generally easier to get hold of a second hand single rail o/d box, which is the way to go - trying to convert your current 'box means laying your hands on everything from an o/d mainshaft rearwards (RKC767 for a single rail/TKC923 for a 3-rail with D-type/TKC899 for a 3-rail with J-type).