*** 5 SPEED MARINA GEARBOX CONVERSIONS FROM £30? ***

[The original northen boy]

OK so perhaps this sounds too goo to be true?

I was thinking just the other day has anyone investigated the possibilities of using spline adapters in the fitting of an alternative gearboxes to the Marina?,for those of you who are unaware of these little gems here what they do,in the most simple terms they step down (or step up) one splined shaft to another or in some case alter the number of splines from one to another number (either higher or lower) and can in many instances be used for gaining extra length to say a drive-shaft,input shaft or for a power take off unit.



The Marina gearbox uses a long input shaft,far longer than many other manufactures,a consequence of the very deep bell housing that the all cars use,so on the surface of things making many alternative choice impractical because their input shafts are simply too short,what the spline adapter could possibly do (and i say Possibly) is to give extra length and lengthen the shaft at a fractional cost simply by bolting straight on to the original gearboxes input shaft (with the addition a spot of Liquid adhesive thread glue) the only extra work required would be the Turing/grinding down of the spline adapter end to fit the back-plate spigot bearing.

The old bell housing could be used only with the addition of new gear box mounting holes being drilled,a simple gearbox support bracket could be formulated with strip steel (or channeled strap steel) and perhaps even use the existing gearbox mounting holes,the clutch could possibly be left standard as indeed the clutch mechanism of course you would need a viable gearbox to start with but the need to remove internal metal work by cutting could be drastically reduced or even made unnecessary as the most common cause for this measure is the use of an incompatible bell housing and as the correctly fitted standard unit is being reused making things far safer as this often dangerous practice of cutting out and weakening the cars structure can be eliminated completely.

Spline adapters start at the £30 mark (even cheaper for some) and can handle up to 100 BHP,so that old 5 speed box at the back of the garage could be of some use after all you just need the correct spline adapter to fit it and some spare time.And maybe making the choice for the "ultimate gearbox swap" The Toyota Supra.Well worth investigation i think!



Russ

Beckett Bros "i've seen the yellow lights go down the Mississippi" :roll:

[MarinaCoupe]

Interesting idea Russ, as you know Steve and I have a conversion plate for the V6 Sierra Type 9 gearbox to go into the Marina. The reason we use that is because the 4 cylinder Type 9 version of the gearbox, the input shaft isn't long enough. Can you email or PM me the website link for this company?

It might be possible to find an extension that will allow the use of the 4 cylinder Type 9 version, which are much more plentiful. However initial thoughts are that you would have to cut the spigot off the front of the gearbox input shaft and ensure that the new extension not only has a 1" diameter shaft with 23 splines, but also a spigot on the end of it. None of the ones in the pic have this.

One of our customers is currently looking to fit a long Ford input shaft into 4 cylinder Ford gearbox. However not all long shafts fit - standard 2.8/2.9 V6 shafts won't, but 2.3 V6 shafts will and possibly Transit Diesel shafts might, so time will tell for him, I will post the results here when we know.

[jiversteve]

Hmmm, thats an interesting option. But my first thought is NOT to take the box out of my Supra and put it in my Marlin complete with the twin turbo engine but boy would it shift if only it could be made to fit.!

I like the idea though but I can forsee all sorts of problems, none totally insurmountable.
Any adaptor would need to fit within the constraints of the clutch plate and flywheel but the biggest problem would be the clutch release bearing and carrier. The 1 1/2" ID of the release bearing that must slide over the adaptor limiting the design.

If there was sufficient demand then a custom input shaft to fit a standard Type 9 would be the best option though it would mean some work and would probably be an expensive item to have made in limited numbers. There would still be the need for an adaptor plate to fit the box to the bell housing.

If as Chris sugests the Transit input shaft option works then perhaps that is the best option.

[MarinaCoupe]

Russ,

I found the website that you got the picture from, they seem to be for Tractor power take off (PTO) auxilliary drives for add on equipment. Most are rated at only 75hp, although one or two are 100hp. I think that the principle is interesting, if one could be made to overcome the clutch release problem that Steve cited and came with 1" diameter and 23 splines like the Marina and Ford.

Spline Adaptors

To give you some idea of alternate costs, a suitable new Type 9 input shaft is £59.00 plus fitting. I think that your example of a Supra gearbox is good although they seem to go for £150 - £200 plus, a lot more than a Ford Type 9 box and approaching used Borg Warner/Tremec T5 Cosworth prices.

[The original northen boy]

Ay up Chris and Steve,

Glad you found the link to the web page where the initial photos for the spline adapters came from,indeed you are correct Chris the one show there are all for tractor PTOs to allow the addition of farm machinery

Typical applications include:
Running a water pump on a fire engine or water truck
Powering a blower system used to move dry materials such as cement
Raising and lowering a tipper truck bed
Operating the mechanical arm on a Cherry Picker used by electrical maintenance personnel or street light maintenance crews
Operating a winch on a tow truck
Operating the compactor on a refuge vehicle
Operating a Hiab/Grapple vehicle

It is also possible but less common to connect something other than a hydraulic pump directly to the PTO,such as grass cutters and cultivators,and perhaps as we speak even Marina gearboxes!

I believe that some spline converters do exist for automotive use albeit for the most the performance part of the market,below i'm informed is an example fitted to a Borg Warner T5 gearbox made the American Company Offenhauser (of a shaft sleeve and spline converter fitted using a sweat fit to the input shaft of the T5 gearbox) taking the original 26 splines down to 14 the T5 is a common up-grade for the 5.0 Ford Mustang and can amply accommodate 400 BHP,in theory therefore should the spline converter

please note i have not verified the authenticity of these photos





Russ

Beckett Bros "i've had a red light on mi wrist" :roll:

[Martec]

Bought and removed a late type 9 gearbox from a sierra in a scrap yard as a spare/next project engine arrangement for £50 + 12 scones!

Trouble is it has an electronic output for the speedo, not sure how to convert it yet.

Brian

[MarinaCoupe]

Hi Russ,

Interesting pics of T5 gearboxes, comparing the two housings, you can see that the ally casings are different, so I doubt if it is a conversion. The first one has "WC" written on it in pen which usually signifies "World Class" i.e. like a Cosworth or V8 Mustang etc. The second pic has "Non WC" which means "Non World Class" these can only handle 200 ft/lbs torque.

They all come with varying input shafts depending on their source, with different lengths, diameters and number of splines. T5s have been used by both Ford and Chevrolet in both cars and trucks, together with various other cars round the world. The English Cossies use a 1" diameter input shaft and 23 splines like the Type 9 and Marina boxes and would be a great conversion if they weren't so bl***y expensive.

I have a raft of research on them, awaiting the day when I dig out the Rover V8 engine and build a Marina V8 - very long term though. Speaking of V8s, does anyone know of what happened to the blac and pin-striped Marina pickup with the V8 in it? Sorry to hi-jack the string.

Brian, do you mean that you have bought an MT75 gearbox? I'm told that if you get a V6 4x4 version and a 2WD version, you can easily build a 200bhp and 200 ft/lb gearbox by swapping the 2WD output casing and tailshaft onto the 4WD box/bellhousing.

The 4WD boxes were setup for Cosworth V6 Scorpios - so bags of strength.

[The original northen boy]

Chris i concur with your assessment,and clearly the box casting are well and truly different,and yes to the World Class (WC) and Non World Class (NWC) designation is clearly visible,so from a conversion point of view of limited use,but it does show how a possible adaptation could be fabricated by a sleeve adapter and spline converter,or sleeve adaptor and section of an old input shaft.

Russ

Beckett Bros "I've seen the bridges of the world and they're for real" **out of sequence** " :roll:

[locost_bryan]

I have a raft of research on them, awaiting the day when I dig out the Rover V8 engine and build a Marina V8 - very long term though. Speaking of V8s, does anyone know of what happened to the blac and pin-striped Marina pickup with the V8 in it? Sorry to hi-jack the string.

Just to add a few more options to the mix. Leyland in Australia used the Rover V8 bolt pattern on the OHC E6, so that they could use the same bellhousing in 6-cylinder and V8 versions of their early '70s P76 saloon. When they fitted the E6 to the Marina 262, it got the Borg Warner 3-speed as standard. The Borg Warner 4-speed is a direct replacement (with a shortened driveshaft). The good news is that there are bellhousing adaptors available from the likes of Dellow Automotive and Castlemaine Rod Shop to fit a variety of 5-speeds to the P76 V8 (and therefore the Rover V8) 8) . Toyota Supra and T5 (Ford or GM Holden) are the most common choices.

[Alan The Exocet]

What an interesting reply Bryan,surly it cant be that hard to find replacement off the shelf parts to adapt other gearboxes to it to the Marina,the MGB has been around forever so there must be more than one 5 speed gearbox conversion to use,apart from from the obvious MGB overdrive option.

Alan

[The original northen boy]

On reflection surly the the best replacement 5 speed gearbox should in theory be the LT77 either from the Rover 2000 SDL which had the 2.0 litre O" series engine (of which only just over 20,000 were built) the 2300,2600,3500 SD1,or TR7,Range Rover and Land Rover Discovery all used them in different ratio specification.Freight Rover vans are also the same, but with far lower ratios, indeed the same as the 2.0 litre "O" series models.

The Rover 2000 SD1 and Leyland/LDV both have a ratio of 3.9:1 and the same bell housing needed to fit them to a Marina i believe.

The Rover LT77 gearbox.

Russ

Beckett Bros "this is the station" :roll:

[jiversteve]

Isn't the holy grail here a 1.8 Diesel Sherpa van??
IIRC that was a B series block with a LT77 box attached.
With a little luck, that would mean stripping off the back plate from the Sherpa block and bolting it all back onto a Marina. I dont know what clutch and flywheel might be involved.
If a backplate could be found it may be possible to get some pattern laser cut for those wanting to try this route.

[MarinaCoupe]

Early 1.8 Sherpas used the Marina 4 speed box, although I believe some got the LT77. I think Crashbang did the LT77 conversion on a Marina or Ital, so if you really need the details, hopefully he'll post some notes here.

The thing about the LT77 is that it is 'kin heavy, some say 40Kg more than Marina and 30kg more than Type 9, T5s are about the same as Type 9.

I am sure that there are other options, but the Type 9 V6 takes a lot of beating - but then again I would say that wouldn't I?

[Alan The Exocet]

Just to go back to the first post is a spline adaptor a easy way and cheap way to match a five speed box to your Marina or could you use a shaft sleeve and the end of a old marina input shaft?
And if the Lt77 gear box has been fitted to the o series Fright Rovers that has to be the best option to fit to the Marina hasn't it? There is a commercial breakers not too far from me i might give them a phone to see what they have in stock,can there be that many people after them.

So what what is need to fit a Lt77 then? engine back plate or is that the same for b and o series engines and of course the gear box but will that fit without cutting?

Ta Alan

[jiversteve]

Going back to LT77 boxes, and Chris touched on this, one of the problems with the LT77 is its weight and size. It was principally used on larger powered vehicles and it's mechanical design is physically larger to take the greater power and torque of V8 engines. Carting around an extra 30Kg all day, everyday, will effect performance and fuel economy, all for the benefit of a 5th gear .

The V6 Type 9 is at its design limit when used in 2.8 cars. The weak link is the lay shaft bearings and there is a standard upgrade that beefs these up to take the power more reliably. Infact there are some Ford modified ones out there that use a modified bell housing with a cut out for the larger layshaft bearing housing.

Stating the obvious, the problem with any gearbox swap, is that so many modern cars are FWD. Gearboxes for modern RWD cars tend to be designed for higher powers and are therefore larger and heavier. Finding an appropriate box that is readily available, not too heavy and will fit under a different car without too much body modification is a matter of trial and error. Perhaps the best source of modern gearboxes that might fit would be BMW's, who generally seem to like RWD only vehicles.

Certainly one of the advantages of a Type 9 is that it was common to so many cars and that they have, and continue to be in demand by many Kit car builders and car modders. Even today, you can buy brand new alloy castings of the gearbox body, and all the internal parts continue to be manufactured by specialists.

There cannot be many mass produced items, like the Type 9, that continue to recieve that sort of support some 17 years after the OEM stopped production.