Dolly 1850 single rail gearbox in to mk3 GT6

[ahebron]

1 hour ago, Graham C said:

I went this route Single rail with j type OD as I was told numerous times this was the better combination. It has been an interesting journey and hopefully near to completion. 

Sorry to cause confusion/ concern to anyone who read this thread.

Be nice to get the car back on the road.

Graham

No don't apologise. This has been great with everyone chipping in with various bits of information helps us all to learn more about these gear boxes.

[Graham C]

Colin,

"so I've been following the thread with great interest and like to think I've learned something too. "

I have learnt a lot, besides sorting cars out with mechanical probems, getting cars back on the road, general maintenance I have always kept them original. This is the first time I have actually fitted a non stnadard part to one of my cars and had to adapt things to fit, hence my numerous enquires over the previos year before starting.

The thing it has shown me is that the forum is very useful and there is good advice out there with good people providing help.

The secound thing even when you have done all your research they will be something that trips you up, for me the drive to the speedo. I assumed it would be OK and did not check, in hind sight I could have measured out the position and checked the gap.

I have ordered a GT6 plastic tunnel from Moss and fingers crossed I hope it fits, considering the extra length of the OD and gearbox.

Anyone interesested in a cardboard original tunnel which has been lined with fibre glass to stiffen it up. Free to a good home if usefull to someone. Was fitted when I had an the non OD box.

If interested then PM.

To good to throw out.

Graham

 

[ahebron]

Without us making mistake and admitting to them this forum would be a very quiet place😉

[Colin Lindsay]

7 hours ago, ahebron said:

Without us making mistake and admitting to them this forum would be a very quiet place😉

Have a look at the 'blonde moments' section..

The single-rail is not a conversion that I've ever done, but from following the thread I've noticed a few things that I wouldn't have thought of. With our gearbox parts becoming hard to find it's another option to consider.

[ahebron]

I also have a Type 9 box and Canley adaptor sitting on the shelf. I also managed to pickup a NOS V6 input shaft. 

Just in case this doesnt work for some reason

[Peter Truman]

Ref using the single rail box with a GT6 bell housing rather than cutting the bell housing, skimming the gear box case , and carving up the clutch lever I think I’d go the concentric and axial internal clutch slave cylinder mod. Then the only bellhousing mod would be the selector rod housing.

Peter T

[johny]

Don't understand Peter, surely a single rail in a Gt6 is just selector rod housing, propshaft and in Grahams case speedo angle drive?  No clutch or additional bell housing mods needed I think...

[Peter Truman]

Earlier in the topic it shows the clutch lever having to be modified (cut) to clear the extra height of the single rail box and if I remember the front right corner of the gearbox case trimmed to clear the lever.

whereas using a concentric clutch the lever aperature in the bell housing doesn’t need modifying as only the slave feed pipe and bleed pipe has to pass through the normal lever aperature.

Peter T

[Graham C]

Peter, you are correct I did modify the clutch lever and cut the corner of the gearbox, the corner was removed as a precaution as I was not sure how much travel I needed and I only wanted to put the gearbox in once. If I was younger then I may have carried out a trial run of fitting and foud out what I needed to cut or not.

Your idea of a concentric clutch sounds good and another way of solving the problem. Both ways have pros and cons. Any idea which concentric and axial internal clutch slave cylinder mod would you have used?

Also I need to mention that on using a GT6 clutch slave cylinder I had to insert washers between the cylinder and bell housing to move it slightly back, this was to enable me to change gears as they were catching when I did. I was lucky that the original bell housing came with a dolly slave cylinder and I noticed that it had thicker legs which the bolts went through into the bell housing.

Remember I was using a dolly clutch parts in a GT6 housing so this may have caused a problem, however now the gears change nicely. I may refurb the dolly Slave cylinder going forward and try that to see it works.

Graham

[johny]

Ok yes I can see the Dolomite bell housing looks like it has its slave cylinder mounting and aperture for the lever slightly further round to the horizontal so allowing what I believe is the same lever to be used without hitting anything. Interesting that the slave cylinders are different....

[johny]

In fact now, as Ive got an 1850 non OD single rail box I want to use in my Vitesse (not a great fan of overdrive), I think I should put the internals in a 3 rail case and carry out some drastic surgery to the tail casting. It should avoid the previous issues except for propshaft length (I'll need a standard OD prop), clutch friction plate, speedo cable (opposite side of gearbox and different fitting), and there'll be a hole in the top of the  rear casting that'll need sealing somehow....

[Clive]

4 minutes ago, johny said:

In fact now, as Ive got an 1850 non OD single rail box I want to use in my Vitesse (not a great fan of overdrive), I think I should put the internals in a 3 rail case and carry out some drastic surgery to the tail casting. It should avoid the previous issues except for propshaft length (I'll need a standard OD prop), clutch friction plate, speedo cable (opposite side of gearbox and different fitting), and there'll be a hole in the top of the  rear casting that'll need sealing somehow....

Have I missed something? Just swap the bellhousing, use a top-hat tube thingy for the selector shaft, and an OD prop should fit? Or are you a fan of the 3 rail selectors? 

(afraid I can't help with your aversion to OD.... best thing to do to a triumph is my experience!)

[johny]

Have a look at the additional issues Graham had above. Turns out the dolomite clutch slave is in a different position on its bell housing than the 3 rail one....

[Clive]

10 minutes ago, johny said:

Have a look at the additional issues Graham had above. Turns out the dolomite clutch slave is in a different position on its bell housing than the 3 rail one....

But if the vitesse bellhousing is used, it should work perfectly. I don't really understand the clutch fork issue, on the pothers I have seen I don't remember any problems. The clutch fork is the same on the gt6/vitesse as both flavors of dolly 1850 box. 

[johny]

I think the 1850 bell housing was different to move the clutch fork further away from the selector rod area and possibly give sufficient clearance for the extra height of the main casing which would explain why the mods are necessary.

[Peter Truman]

Graham I tried responding late last night our time via my iPhone, but it went thro to the webmaster so I'll repeat part of it.

"Graham excellent work, ref the concentric clutch slave I think the US boys went into it "Line & Verse" on the Triumph Experience Forum, which one, how to mount, reqd throw, where available etc. If you want I can try and search for it & advise, I think I might have some reference data filed".

Again a great job, everyone now has a better understanding of what's required, what the options are and indeed the pitfalls.

The obvious easy solution if you can find it is to use the early Dolly 1850 3 rail J Type overdrive box, a shoe in except the clutch plate!! BUT who last saw one of those in captivity!

Even the most recent posts re the Dolly slave cylinder location and its different throw to the Vitesse's has made me realise the slave I have probably isn't suitable if I do the 3 rail conversion, and the standard single rail OD adapter plate can be used & seals with the 3 rail box conversion and will avoid that additional 1inch annulus I used on my daughters Mk2 single rail internals into the 3 rail case using the Spit IV adapter plate won't be required!

This thread has been a wealth of information for ALL & shows the advantage of the clubs Forum to all and sundry.

Thanks again Graham.

Peter T

[Clive]

 

I fitted a concentric slave to my spitfire (type 9 gearbox, zetec engine) so so little different, but not much.

I initially used a Mondeo cylinder, made the mounting plate. Getting the trow is tricky, as you MUST allow for wear in the clutch plate, and I don't think the guide/instructions suggest enough. They all say 3-4mm, which looks like the thickness of the linings, but the cover fingers will move much more. I need to mock up a worn clutch plate....

In the end, as time was tight, my home made adaptor was not accurate enough and the bearing squealed after a few test runs (my plate was made using a holesaw and grinder ) As I was about to do 3K in a few days all over europe, I bit the bullet and bought a  CSC (saab copy I believe) and mounting plate kit from Rally Design, only to discover the spacers were only available from Burton. Anyway, that has worked fine, but the aftermarket nature of it worries me.

If I had the time and a friendly machine shop, I would rather use an OEM cylinder. Need to find one where the bearing face shape matched the existing, so rounded. Below is a link to another type 9 setup, but with picture to explain how to measure up etc.

 

http://www.rwdmotorsport.com/downloads/hydraulic_release_bearing_kit_instructions.pdf

 

 

[Peter Truman]

Graham C as indicated here are some info/photos of  GT6 installed Tilton Concentric clutch slave cylinder type 62-806 installed on a 3 rail due to the original lever failing. Info from the Triumph Experience Forum, there were other installs there too.

The install was by an Sydney Australian enthusiast some years ago, and comment was still working well years later, I have seen other installation photo's where the bellhousing wasn't grooved for the bleed fitting, maybe a 90 degree bend rather than 45.

Peter T

[rlubikey]

Thank you for posting that information about Concentric Clutch Release, or Concentric Slave Cylinder (CSC)  installations Peter & Clive. I'm now watching this thread with interest as I'd quite like to do something like that on my Spit.

Cheers, Richard

[Pete Lewis]

is it possible to make up a concentric base adaptor by making /moulding some resin to puddle on the hsg face and make /mould  to accept whatever slave you pick 

even our of a plastic block or even hard wood   it only takes compressive load . 

Pete

 

[Graham C]

Thank you for taking the trouble in posting this information, very interesting. It looks a very neat engineering solution. It does avoid using the clutch lever which pivots on a ball and held in place by a spring which does not seem very secure. On fitting the fork the spring did seem brittle.

If I have to pull the gearbox out in the future, I would seriously consider this as a project.

It is good that people are adding to this thread with more information. When I started it the idea was to bring together as much information/learnings on this project to help others.

Graham

[GT6M]

Why any body would want t,use a single rail is beyond me,

its bigger, heavier, totally numb t,work on, and no as good a shift

Bung yer bits into a 3 rail case

 

M

[johny]

Surely thats when you get the problems of the single rail mainshaft being longer though?

[GT6M]

Nope,  If ye got a single rail mainshaft, use a single rail OD adaptor,                                              slightly modded so 1 inch longer shaft will fit simples.

And, ive seen adaptors that no need a wee mod, as longer / thickerr than Dolly 3 rail, but same shape, so nee mod to top bit needed

[Peter Truman]

Firstly Pete re using a resin adapter as the concentric slave is in compression, remember when the clutch is engaged the rotation of the clutch release bearing will put a frictional rotational force on the slave housing so it should be positively held, also the slave needs to be accurately positioned so the circumferential gap to the input shaft is equal all the way around. I think I'd prefer a positive restraint as per the fabricated adapter plate,

Marcus I agree on adding up the pros an cons when I convert my Mk2 Vitesse to a J type (ex Dolly 1850 single rail donor) I'll go the same route as I did for my daughters Mk2 Spit J type OD conversion where I used a Spit 1500 single rail internals into a GT6 3 rail case, but I've learnt some do's and don'ts on that journey.

1.On the Mk2 Spit I used the Spit MkIV J type adapter plate 313085 (used with a small tip mainshaft TKC899), which required an additional 1in wide annulus to get the overdrive to mate to the gearbox, in retrospect I should have used the standard Spit1500/Dolomite 1850 single rail to J type adapter RKC634 as it is the right length & it will mate/seal to the rear of the gearbox case, but there will be an overhang at the top above the 3 rail case, remember the single rail gearbox is a lot taller than the 3 rail.

2. Remember there are two spacers required on the MkIV 3 rail selector shafts that have to be fitted to any Spit 1-3, Single to 3 rail conversion, these are to stop selecting two gears simultaneously, first is the reverse selector shaft washer 158585 (NLA, ex UK, but I got one out of the USA), & 1st/2nd selector sleeve UKC0706 (can't remember that one!). 

3. The Spit MkIV 3 Rail box with a 21 tooth reverse idler is the same as an early Spit 1500 Single Rail & uses the same layshaft 154829, but the later Spit 1500/Dolly 1850 I think used a bigger tooth reverse idler with 17 teeth, this had a different bigger toothed layshaft UKC8750. Where am I going with this ie the 3 rail reverse selector lever needed significant modification to adapt to the single rail reverse idler and engage the reverse selector shaft, with Marcus's advice at the time I had to belt the hell out of it to get it to engage the reverse idler and upper selector shaft, in fact I half cut thro it aligned it and welded it back up. The issue was I used the Single Rail Reverse Distance Piece 22G1435 which came with the Single Rail box, where I should have used the Spit MkIV 3 Rail Distance Piece 137687 which I believe is shorter and would let the Reverse Lever throw more! As the Spit MkIV 3 Rail & earlier Single Rail Spit 1500/Dolly 1850) Reverse Idler (21 teeth 144580) and Layshaft (154829) are the same gear selection/meshing should have been OK.

4. Then there's the issue of the speedo drive gearing using the std early Spit 4:11 diff ratio, I'll have to look at my records up I found a little referred to J Type OD US specific pinion that I think should be pretty accurate? Who looks at the Speedo anyway, I drive by the revs & know their respective speeds.

Oh re the suitable 3 Rail Gearbox Cases for the conversion, on the Spit I used a GT6 one, but I've been told all the cases are actually basically the same the only difference being the later Spit MkIV and GT6/Vitesse/Dolly Cases have 3 tension springs (113532) to preload the front Layshaft Thrust Washer (113229). Question, is this the case "are all the 3 Rail Cases basically the same?? If they are it will save me money and time for the Vitesse conversion.

Oh I do wish I could find the earlier Dolly 1850 3 Rail J Type OD Gearbox, what an easy replacement for the Vitesse that would be, just the clutch, speedo pinion & gearbox mounting to sort, I have spare Bellhousings! Dream On!

Please tell me where you think I'm wrong or stuffed up, or what I've forgotten.

 

Peter T