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Mystery gearbox


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The Hi, I have here more photos as requested. Sadly I doubt my box is anything special, very likely exchange. At one point in my career I worked for a main dealer where I had to rebuild a steering box with a new casing rather than simply fit a new box because it would save eight pounds! Maybe that happened with this box whilst under warranty? I will let you know if it turns out to have 5 gears and overdrive as well! Regards Alan.

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Hi, Thanks to you all for your feedback! I do have another question.... The missing isolater switch. I have seen pictures of a switch on a bracket on some saloons at the base of the gearstick for the reverse lights, is this one to prevent overdrive selection in reverse?. Also, by the way, I have the original non overdrive box, which has a switch either side on the gearbox top. Bearing in mind the car came back from the states, what is the second switch for? Regards Alan.

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To the best of my knowledge, there has never been a manual switch to lock out the O/D in reverse. My A type has two switches on the G/B operated by the selector rods. One locks out operation in reverse and the other in first  and second.

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Just for the record - a bit pedantic probably.

Mike, your switches are one which is switched on to allow O/D in 2nd, another to allow O/D in 3rd and 4th. 

If neither of the switches are 'on' you cannot engage overdrive so there is no need for an interlock switch on reverse because you never want it in that gear.  

 

 

Edited by RobH
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3 hours ago, RobH said:

Just for the record - a bit pedantic probably.

Mike, your switches are one which is switched on to allow O/D in 2nd, another to allow O/D in 3rd and 4th. 

If neither of the switches are 'on' you cannot engage overdrive so there is no need for an interlock switch on reverse because you never want it in that gear.  

 

 

Now I think my 'boys' book of rally cars' said the Triumph Barb & Innsbruck rally cars used o/d on all 4 forward gears.

Where as,  Dolomite Sprint had a CR gearbox ratios with o/d on 4th only to give a 5th gear.

How about....

Overdrive available on all 4 forward gears all the time that the reverse gear is not selected. 

Select the reverse gear and the reverse selector inhibit switch will energise a relay that disconnects the power between the od switch and its operating relay.  At the same time it will energise the power to turn the reverse lights on.

Peter W

Edited by BlueTR3A-5EKT
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7 minutes ago, BlueTR3A-5EKT said:

How about....

Overdrive on all 4 forward gears all the time that the reverse gear is not selected. 

Select the reverse gear and the reverse selector inhibit switch will energise a relay that disconnects the power between the od switch and its operating relay.  At the same time it will energise the power to turn the reverse lights on.

 

That is something of a digression from the topic under discussion Peter and apt to cause confusion but  ...... Fine if all you want is overdrive ratios and never straight drive........ I can't see any point in that, can you? 

 

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My O/D lockout switches now lock it out in reverse and 1st and 2nd. When I first got the car it was a survivor from the boys own hill climb races- the O/D switches were bypassed and I could engage O/D in any gear- jumping  when the O/D was accidentally left on in reverse prompted me to have a look at the wiring. Fortunately nothing seems to have been damaged.

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Coming back to the experimental 5 speed gearbox, I would like to show an image of the front of it. If you have

a close look to the front cover you see an extension downwards which covers another ball bearing beneath the

main bearing. This is one of the improvments: The layshaft does not have these weak needle bearings

any more but ball bearings. Dieter

IMG_20210505_131449.jpg

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  • 1 year later...
On 5/6/2021 at 8:58 PM, rcreweread said:

Certainly looks like a saloon box with the smaller input shaft and the crossmember in the background, and fitted with what looks like an A type overdrive - strange that there are no inhibitor switches on the top cover though it looks like the reversing light one on the side has been removed so maybe a top cover has been fitted from a non overdrive box. The only other thing which looks a bit strange is the adapter plate between the OD and the gearbox which is normally aluminium. I'm sure someone told me that the works rally cars changed this alloy plate for a steel one as they had a tendency to warp/bend - the adapter plate in the photo looks thicker than an alloy one and it looks rusty indicating that its steel/iron so maybe there is a bit of strange history going on?!

Cheers Rich

Hi rich, I have now cleaned and stripped this gearbox, and to my delight have discovered several items all of which seem to confirm your rally car theories! First of all, when I started to clean the exterior I discovered written on the top of the bellhousing written in yellow paint the words WORLD CUP . Then I noticed the bolts that secure the spigot shaft and lay shaft retaining plate are lock wired. I then dismantled the contents of the box and to my delight found a 3 bearing layshaft + needle bearing thrusts. Thanks for your help, without it, I would never have known! Regards Alan.

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We have a couple of these gearboxes here. They were indeed built for the World Cup PI's. There should be another in circulation that was robbed by a specialist from one of our customers cars many years ago (was substituted with a standard box).

They are basically Police spec in that they have Stag internals, but saloon size inputs. The overdrive adapter plate should be steel, and the A type has special accumulator spring. The overdrive comes in with a proper thump as a result, and I have to dip the clutch on the way down the box.

If you need anymore info I have rebuilt a couple of them, and Dave at Overdrive Spares has the specs for the overdrive (Overdrive Spares founder Ernie Garbut was actually working on the World Cup rally servicing the things)

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On 5/7/2021 at 5:58 AM, rcreweread said:

Certainly looks like a saloon box with the smaller input shaft and the crossmember in the background, and fitted with what looks like an A type overdrive - strange that there are no inhibitor switches on the top cover though it looks like the reversing light one on the side has been removed so maybe a top cover has been fitted from a non overdrive box. The only other thing which looks a bit strange is the adapter plate between the OD and the gearbox which is normally aluminium. I'm sure someone told me that the works rally cars changed this alloy plate for a steel one as they had a tendency to warp/bend - the adapter plate in the photo looks thicker than an alloy one and it looks rusty indicating that its steel/iron so maybe there is a bit of strange history going on?!

Cheers Rich

It is an A type overdrive but why/how is the solenoid horizontal rather than vertical? I've never seen one like that.

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24 minutes ago, John McCormack said:

It is an A type overdrive but why/how is the solenoid horizontal rather than vertical? I've never seen one like that.

Saloon fitment is like that.

Stuart.

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As a treasonous colonialist, I am a bit confused. To recap, this is a works rally cup experimental 5 speed gearbox with stag internals and an overdrive that works on all forward gears (5)? And it seems that even though it was for a saloon? it had been fitted to a TR6? Holy cow. If Moss had put an overdrive unit on that bespoke Vitesse (Mazda) box, that would be a modern equivalent of this unicorn.

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11 hours ago, stuart said:

Saloon fitment is like that.

Stuart.

Thanks. I have a saloon box with J type od but haven't seen that before.

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Picture above of one of the gearboxes currently out of the WC car for some work. I can't get at the other one currently to see its number, but it's less than twenty. I suspect there were only twenty odd built for the WC cars, one each for the five cars, and a couple of spares each for the rally itself.

I'm keeping the number of the 'misappropriated' one close to my chest should it ever come up for sale!

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On 7/5/2022 at 8:58 AM, Tom Chatterley- Cox said:

I'd say its very likely to be an ex-works box wit the steel adaptor plate. They're quite the rarity! The rest of the box looks completely correct for saloon, the top cover may have been changed though by the looks of it. 

All the adaptor plates are aluminium A / J or D type as standard.

Tom

See my identification of them above! They were built specifically for the 1970 World Cup Rally 2.5PI saloons.

 

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From John Kipping.

https://www.canleyclassics.com/?archive=5-speed-gearbox

 

5 Speed Gearbox

This is one of the mythical Triumph 5 speed gearboxes, predating the later 77mm 5 speed that appeared in the TR7, Rover SD1, etc.

Looking like a normal Triumph saloon, TR 4-6 alloy gearbox with a bit tacked on the back, this is essentially what it is! Ours is numbered EX5SPD/1 (experimental 5 speed number 1), I know of another in Germany, and there was supposed to be another in a big saloon somewhere up North? Ray Henderson once told me on one of his visits here that 'it wern't nought to do with us' (Triumph)! He later rang me up and appologised, he had spoken to Triumphs chief gearbox guy at the time who had confirmed the project had indeed happened, prompted by the intervention of a certain Mr Kas Kastner. All the ones I have seen or heard of have had saloon input shafts, and have at one time or another been fitted in saloons, not TR's, unless anyone knows differantly? Why didn't they go into production with this instead of the incredibly heavy cast iron case, clunky old 77mm box I will never know?

 

image.png.f079c26e249943986c373e3c26fe1370.png

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22% or 28%? Whilst I have my overdrive in bits I have the opportunity to change the ratio. This is going into my import 6. I believe these have a lower ratio diff, so am I correct in thinking the 28% gearing is the right way to go in order to drop the revs on the motorway? Also, could someone please re- assure me I have marked up the gears correctly! The 22% set have much larger planet gears. Many thanks Coops.

E4E17831-4A4A-4C7D-9953-F0E0BFCCA0D9.jpeg

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25 minutes ago, Coops said:

22% or 28%? Whilst I have my overdrive in bits I have the opportunity to change the ratio. This is going into my import 6. I believe these have a lower ratio diff, so am I correct in thinking the 28% gearing is the right way to go in order to drop the revs on the motorway? Also, could someone please re- assure me I have marked up the gears correctly! The 22% set have much larger planet gears. Many thanks Coops.

E4E17831-4A4A-4C7D-9953-F0E0BFCCA0D9.jpeg

They look right to me - as you said the 22% has larger planet gears than the 28%. The easy way to tell is if you take the sun gear out, can you remove the brass thrust washer? If its stuck behind the planet gears its a 22%, if it easily comes out then its a 28%.

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Thanks guys, that’s all useful info, I hadn’t noticed the marks on the sun gears, presumably the idea is to avoid whining? As I’m not even sure I have put the same centre piece in I may have a singing gearbox! At least I’ll know why..... I’m glad to be sure I’m putting the right ratio in, am I right in assuming the 28% gives me lower revs when cruising? Regards Alan.

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