Fitting a saloon gearbox to a TR3a

[Ian Vincent]

I have acquired a Triumph 2000 Type A gearbox with overdrive and want to fit it to my TR3a.

 

The Overdrive is off being converted to TR spec at ORS in Sheffield and I am now considering what to do with the gearbox itself.

 

I have whipped the top off and it looks pretty good and there was minimal detritus around the drain hole but my concern is the clutch. I have a new TR driven plate and a new Saloon driven plate - both are quality items with the full complement of rivets but I have to say the TR item looks a lot more 'meaty' than the Saloon one and is also 9 inches in dia as opposed to the saloon one being 8.5 inches.

 

So my question is, will the saloon clutch be man enough for the job, bearing in mind I don't drive like a lunatic and haven't had a clutch fail on me yet, or should I change the input shaft on the saloon gearbox. And if I do want to change the input shaft, is the input shaft out of the 3a box a drop in replacement to a saloon box? I wouldn't have thought so but who know knows?

 

I have done a search of the various threads on the forum and can't find anything conclusive, all I can find is a suggestion that there is a 9 inch Izuzu clutch that might fit but with two driven plates already - I didn't want to buy a third.

 

And a second question on the same theme, if I do keep with the saloon input shaft, the Moss catalogue suggests using the TR clutch fork, bearing and sleeve - which is going to leave an lot of space between the sleeve and the input shaft - does that matter?

 

Any help appreciated.

 

Thanks Ian

[Mk1PI]

Use the saloon input shaft and clutch bearing/carrier etc. Clutch will be lighter and more pleasant generally. I have 190lb ft of torque in my PI saloon and it copes just fine using the smaller input shaft and a paddle clutch plate... I have NEVER heard of one failing.

 

As for 9" -v- 8.5" I believe the clutch cover only has 8.5" of pressure plate anyway

Edited October 21, 2009 by Mk1PI

[Mk1PI]

Sorry just read the second part of your post in detail. I will check tomorrow at my friendly Triumph grage in Perth (the owner has a TR2,3,6,8,Spit6 ,Stag and 3.8 E-Type DHC) He has imported and converted a lot of TR's to overdrive (A and J) and knows the various Triumph 'Meccano' box of tricks better than most. I will check on clutch mechanisms but I suspect a saloon set up will be easiest and fit fine.

[BrianC]

Unfortunately I can't help, but just to avoid potential confusion/misunderstanding for those who may be able to (and anyone else contemplating a similar solution)can you confirm that you are referring to the original TR2-4 3-lever clutch rather than the diaphragm clutch introduced on the TR4A (and subsequently fitted by some owners of earlier cars with weak left legs )?

[John Morrison]

Ian,

 

use the saloon 8.5 inch driven plate with the TR housing, we have a Cumbria Group member did this 14 or 15 years ago, car has never missed a beat, bean all over, le mans , Monte Carlo, don't worry about it, and don't buy any more clutch bits you don't need them.

 

john.

[Ian Vincent]

Brian,

 

Yes I am planning to continue to use the original TR2-4 3-lever clutch and in view of the comments from John & Mk1 PI (many thanks by the way, will almost certainly retain the TR clutch thrust bearing and carrier and release fork. I am assuming that that to prevent the thrust bearing carrier 'slopping' around it is necessary to use the TR front cover (sleeve) but with an oil seal with an ID that fits the smaller saloon gearbox input shaft and an OD that fits the TR cover. Again I am assuming that such an item is available.

 

Any help on this latter point would be appreciated.

 

Rgds Ian

[John Morrison]

Ian, don't think you need to change the gearbox front cover at all.

 

I think that all the diameters i.e. input shaft , front cover Protrusion? etc are identical.

 

Only differenc on the saloon gearbox input shaft are the size/number of splines NOT the od.

 

Maybe someone can confirm this, if not I have both TR boxes and saloon boxes in teh garage and will hppily measure but will need to be the weekend.

 

john.

[Kiwifrog]

The TR3A 3 Synchro box input shaft will not fit in a saloon gearbox, you will need the later 4 Syncro box type as used on TR4A etc and getting hold of one of those is like finding rocking horse droppings

 

Cheers

 

Alan

[Ian Vincent]

Ian, don't think you need to change the gearbox front cover at all.

 

I think that all the diameters i.e. input shaft , front cover Protrusion? etc are identical.

 

Only differenc on the saloon gearbox input shaft are the size/number of splines NOT the od.

 

Maybe someone can confirm this, if not I have both TR boxes and saloon boxes in teh garage and will hppily measure but will need to be the weekend.

 

john.

 

 

John,

 

I have just checked on my two boxes and the front cover sleeve OD is different on the saloon and TR box but I am reliably informed that once you take the cover off (which I haven't done yet on the saloon box) the diameter of section of the shaft on which the oil seal bears is the same for both boxes in which case there is no problem other than a possible need to reduce the length of the front cover sleeve by about 1/4 inch to make it the same length as the saloon one. Don't ask me why you would need to, it was just something mentioned by someone I talked to.

 

FWIW, if all else fails, ORS will cut down / re-machine a TR output shaft to make it fit an overdrive box for about £100.

 

And thanks for the advice about the TR4a shaft Alan and again I have been told that there are people around who will cut and shut the front end of a TR input shaft to the rear end of the saloon input shaft. One way or another, its going to fit!

 

Rgds Ian

[Mk1PI]

Spoke to David Markich aand he recommends redrilling the flywheel to use a 2000/2500 cover and use all saloon clutch mechanism components. You will get a smoother, lighter and stronger clutch.

Laycock covers are common NOS on ebay.

 

A 2000/GT6/Sprint one is fine for a TR3 torque wise but TR6/2500 covers also crop up. They are heavier in action though

 

http://cgi.ebay.co.uk/TRIUMPH-TR6-LAYCOCK-CLUTCH-COVER_W0QQitemZ180421612517QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item2a01f753e5

 

http://cgi.ebay.co.uk/TRIUMPH-VITESSE-GT6-DOLOMITE-SPRINT-LAYCOCK-CLUTCH-KIT_W0QQitemZ310167091669QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item48376639d5

 

http://cgi.ebay.co.uk/Clutch-cover-plate-Laycock-TR6_W0QQitemZ110444181181QQcmdZViewItemQQptZUK_CarsParts_Vehicles_CarParts_SM?hash=item19b6fc76bd

Edited October 22, 2009 by Mk1PI

[NickKerfoot]

Just a few more gems for this thread - if you use a saloon cover, the saloon release bearing must be used because the larger diameter TR item will touch the cover's operating levers in the wrong place. When I did a similar thing to my TR4, I obtained a TR4A flywheel. A saloon cover is the same as the diaphragm TR unit(apart from the operating levers!)and therefore bolts staight on. This will of course be complicated by which starter motor is currently fitted to your TR3A... a 4/4a one would be required.

 

Regards

Nick

[Ian Vincent]

Just a few more gems for this thread - if you use a saloon cover, the saloon release bearing must be used because the larger diameter TR item will touch the cover's operating levers in the wrong place. When I did a similar thing to my TR4, I obtained a TR4A flywheel. A saloon cover is the same as the diaphragm TR unit(apart from the operating levers!)and therefore bolts staight on. This will of course be complicated by which starter motor is currently fitted to your TR3A... a 4/4a one would be required.

 

Regards

Nick

 

 

Hi Nick,

 

That is one more obstacle to my taking up the eminently semsible suggestion of using a saloon cover because whilst I have a new saloon thrust bearing, I don't have the carrier. So to move to a complete saloon assembly, it would cost me about £45 for a new bearing carrier and £75 - £100 for the new cover.

 

I will keep my eye out for a deal until it gets to the point that I want to re-install the box in the chassis and then make a decision. I suspect I will opt to keep the old clutch mechanism - plenty of people drove them like that for many years - and still do!

 

Rgds Ian

[Mk1PI]

Hi Nick,

 

That is one more obstacle to my taking up the eminently semsible suggestion of using a saloon cover because whilst I have a new saloon thrust bearing, I don't have the carrier. So to move to a complete saloon assembly, it would cost me about £45 for a new bearing carrier and £75 - £100 for the new cover.

 

I will keep my eye out for a deal until it gets to the point that I want to re-install the box in the chassis and then make a decision. I suspect I will opt to keep the old clutch mechanism - plenty of people drove them like that for many years - and still do!

 

Rgds Ian

 

 

I have several old carriers in good nick... much cheapness.. postage would be about 10 quid

Edited October 23, 2009 by Mk1PI

[BrianC]

I hope someone is going to write this up as a technical article for TRAction. Given the number of people desperately seeking A-type overdrives this could help (although perhaps not a good idea as it will devalue my spare )

[Ian Vincent]

I hope someone is going to write this up as a technical article for TRAction. Given the number of people desperately seeking A-type overdrives this could help (although perhaps not a good idea as it will devalue my spare )

 

 

Maybe when I have finished Brian. I have to say the help you get on this forum is really excellent. Life was a lot more difficult before the internet was invented.

 

Rgds Ian

[2SwissTriumphs]

Hi Ian,

 

I was just wondering if you managed to get the saloon box into your TR3 ?

 

I will soon have my dream car (TR3) on the road but the one I agreed to buy is a non-overdrive model. Living in the middle of Europe presents many chances for touring holidays or short weekend trips where an overdrive would be most practical. Through my dealings with 2000 and 2500 saloons I have 2 spare saloon boxes with A-type overdrives so this conversion would make sense for me.

 

Hopefully you can tell me how you did it !

 

Best Regards,

Martin.

[Ian Vincent]

Hi Martin,

 

Yep the saloon box has now been fitted. It took a bit of persuading because of the thicker flange on the bell housing (I had to open out the rear fixing holes) but it is all working. I haven't been able to try it in anger yet because of my slow progress in finishing the car off. However on that front, I retired last Friday so maybe now with a bit more time I will be able to get it on the road for next spring. There isn't a huge amount left to do.

 

Rgds Ian

[2SwissTriumphs]

Firstly, many congratulations on your retirement Ian. I hope this will mean many more happy hours for you and TR3 !

 

Secondly, thanks for the info on the gearbox conversion. I don´t wish to trespass too much on your time, but could you possibly write a short specification list of the parts sources used ?

I am lucky to have good access to most spares at work but knowing which clutch assembly, input shaft, bearing carrier and nose extension etc. would be superb.

[billg]

Hi there

 

I'm at the same stage so will keep a close eye on this thread. Will post some of the ideas I have thought about

 

Regards

 

Bill G @ NB 1959 TR3A

[billg]

Just picked up the OD gearbox today.

 

It's from Triumph 2000 and was missing the gearstick, but it did have the thrust bearing carrier and the cross shaft and fork.

 

Like all 2000's it has a 10 splined input shaft which needs a 2000 /Vitesse/GT6 plate, easily got on EBay. A TR plate will not do as it has a different no of splines.

 

A saloon OD box has a horizontally located solenoid and I think the right mounting plate to create a vertical alignment to suit a TR can be got from Overdrive Repair Services, plus also a new solenoid?

 

Still trying to figure out the rear mounting and if a right angle speedo adaptor is needed and the effect on the speedo head.

 

Hope to post some pics later.

 

The box I bought was supposedly working great and came out of a daily driver that had rust problems. A friend has a test rig so that will be the first move, plus picking up the basic bits I need

 

Bill G @ NB

[billg]

Just picked up the OD gearbox today.

 

It's from Triumph 2000 and was missing the gearstick, but it did have the thrust bearing carrier and the cross shaft and fork.

 

Like all 2000's it has a 10 splined input shaft which needs a 2000 /Vitesse/GT6 plate, easily got on EBay. A TR plate will not do as it has a different no of splines.

 

A saloon OD box has a horizontally located solenoid and I think the right mounting plate to create a vertical alignment to suit a TR can be got from Overdrive Repair Services, plus also a new solenoid?

 

Still trying to figure out the rear mounting and if a right angle speedo adaptor is needed and the effect on the speedo head.

 

Hope to post some pics later.

 

The box I bought was supposedly working great and came out of a daily driver that had rust problems. A friend has a test rig so that will be the first move, plus picking up the basic bits I need

 

Bill G @ NB

[ianc]

A thought: what is the ratio in a saloon's overdrive unit?

 

I ask because the unit normally fitted to a TR2/3/4 has the designation 22/xxxx, which means that it provides a percentage of 22 and hence a ratio of 0.82, the relationship between percentage and ratio being:

Percentage = 100 x (1-R)/R where R is the ratio.

 

Percentage figures of 25, 28 and 32 can be found in the version of the Laycock manual which I have here - none of these figures could be described as 'sporty', especially 32!.

 

If the saloon offers a higher percentage - and it would not surprise me were it to do so since many saloons had such - the performance of the TR in overdrive would be more sluggish and it's possible that the maximum speed would be lower than with direct top, which was a problem with the early Spitfire.

 

Looking at my manual, which I bought in 1972, but seems to cover only as late as TR4 and Squealey 3000, solely the big Squealey, TRs, Ferrari 250GT, Aston DB4 and Standard Ensign (which I seem to recollect packed no punch!) used 22% - all the rest are higher, with the XK150, big Ferraris, Humber Super Snipe, Rovers, Vanguard and Vauxhalls at 28%, and the Rootes' saloons at 32% (perhaps a lower rear axle ratio was specified in this case, for I cannot imagine these 1725cc cars being capable of moving otherwise!

 

Ian Cornish

[Guest ntc]

A thought: what is the ratio in a saloon's overdrive unit?

 

I ask because the unit normally fitted to a TR2/3/4 has the designation 22/xxxx, which means that it provides a percentage of 22 and hence a ratio of 0.82, the relationship between percentage and ratio being:

Percentage = 100 x (1-R)/R where R is the ratio.

 

Percentage figures of 25, 28 and 32 can be found in the version of the Laycock manual which I have here - none of these figures could be described as 'sporty', especially 32!.

 

If the saloon offers a higher percentage - and it would not surprise me were it to do so since many saloons had such - the performance of the TR in overdrive would be more sluggish and it's possible that the maximum speed would be lower than with direct top, which was a problem with the early Spitfire.

 

Looking at my manual, which I bought in 1972, but seems to cover only as late as TR4 and Squealey 3000, solely the big Squealey, TRs, Ferrari 250GT, Aston DB4 and Standard Ensign (which I seem to recollect packed no punch!) used 22% - all the rest are higher, with the XK150, big Ferraris, Humber Super Snipe, Rovers, Vanguard and Vauxhalls at 28%, and the Rootes' saloons at 32% (perhaps a lower rear axle ratio was specified in this case, for I cannot imagine these 1725cc cars being capable of moving otherwise!

 

Ian Cornish

 

 

Yep and you also need check the propshaft length it can be sometimes to tight

[Alec Pringle]

Hi Ian,

 

2000, 2.5, 2500 saloon overdrive was generally 22% A-type and 25% J-type, although a 28% A-type was utilised as an option for at least some export markets.

 

The later Ensign De Luxe with the 2138cc engine was not slow, unlike its 1670cc predecessor . . . . a tad lighter and more powerful than the (by then defunct) Vanguard and it could justify the overdrive.

 

1592/1725cc Rootesmobiles were another story, D-type overdrives until 1972ish, then J-type, but the overdrive ratios varied by model and year - along with gearbox and rear axle ratios. As you rightly suspect, the tall o/d ratio was fitted with a low ratio axle, typically 4.22 but sometimes as low as 4.875. Rootes catalogued various permutations purely for rally homologation purposes - the potential variations of gearbox ratios, overdrive ratios and axle ratios were almost infinite.

 

Any Rootes Arrow fitted with a Holbay H120 lump could give the average TR more than a run for its money, and the Holbay engine could be made to go very quickly indeed. You may recall my having owned a few Arrows as daily drivers in years gone by.

 

Cheers,

 

Alec

[Tr4Tony]

Ian

 

Given the amount of messing about in this process and the high failure rate once its all screwed together, is this really worth doing ? Or should you just get a TR unit ?

 

I've done all this many times and have now arrived at a good solution. My experience is that if you start with a Late gearbox and an 8 spring unit (from all sorts of sources as Alec notes above) it works, but a four spring unit or an early gearbox or a mixture of driveline and geartrain parts usually results in a quick failure. This is with both a standard car and more recently with a higher power and torque car.

 

I have no doubt that mixing and matching saloon and TR bits is possible and can be made to work eventually, but do be aware that its not as easy as some would make out and a great deal of knowledge needs to be acquired to come to a successful conclusion. That is why many TR owners just pay a decent business to do this and as a consequence get something that works well and has some sort of service life.

 

Regards

 

Tony