A-Type Overdrive - What Car is it from?

[Dave Ashworth]

Hi Folks,

 

Can you please help me identify my A-type overdrive gearbox.

 

I think that it originally belonged to a 2.5 saloon car, but is there any way to tell this?

 

I was thinking that I might put it in the TR250 if it is suitable.

 

Thanks for any help.

 

Dave.

[peter clarke]

There will be a number on the gearbox which you can check to see which model car it is from. There is a web site with triumph model, engine and gearbox numbers listed. ........just google. Plenty info on forum re fitting to TR

[Alec Pringle]

The number on the o/d casing may or may not bear any relevance to the internals . . . . a lot can happen over 40 or 50 years, and several rebuilds !

 

Cheers

 

Alec

[Lebro]

The rear casing of the overdrive is different on a saloon. in particular the means of supporting it on the chassis.

A TR one has a horizontal surface on the underside to match up with the flat rear gearbox mount. The saloon type has two vertical mounts on the side of the casing. Also the solenoid is mounted verticaly on the TR, & almost horizontal on the saloon.

There are other differences inside, eg, operating pressures, number of return springs, & possibly size of accumulator.

Also, the speedo cable drive is at a different ratio (3.5:1 instead of TR's 2.5:1), so the speedo will read slow.

 

Bob.

Edited May 7, 2014 by Lebro

[westaj]

Dave,

 

I have a TR250 fitted with an A type overdrive from a 2500 saloon.

 

The o/d number is 22/61973/017142. I understand that, the 22 is the o/d % speed ratio; 61973 refers to a 2.5 PI Saloon 1968-1972. Final numbers are the Serial No.

 

Whereas I believe A 22/61971/etc refers to a TR5 or TR250 unit.

 

My ex-saloon unit is fits fine and has the original horizontal solenoid, I think that you can convert them to vertical at some cost. The rear o/d unit mounting is different and needs some simple mounting modification.

 

With my 185/80/15 tyres, the speedo over reads slightly and I will correct in due course by modification at the instrument.

 

Hope this helps.

 

Jerry

[Dave Ashworth]

Gentlemen,

 

Thank you very much for your input.

 

All the very best.

 

Dave.

[jthierry]

i have also a 22/61973/00139 on my tr 250, a home made mounting, and all works fine . Solenoid is horizontal as on the saloon car 2500

 

regards from Dinard, France

Edited August 4, 2014 by jthierry