Section : Overdrive

will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

Posted By : Tom Broome, 21-Dec-2004, 01:28pm

• will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

  Posted By : Van Hamlin, 21-Dec-2004, 01:43pm

  Not straight on but possible.
  
  1500 input shaft will not fit Mk2 clutch plate, and you can't use the 1500 clutch plate as it is bigger.
  
  According to the Triumphtune book you need 1500 rear crank bush and clutch, dolly 1300/1500 flywheel, Mk2 ring gear and starter.
  
  I think, although I'm not sure, you could probably do it by putting the Mk2 input shaft into the 1500 box. Not as hard as it sounds as you don't actually need to dismantle the box much to do it.
  
  You'll also need 1500 OD prop (or get yours shortened by Dave Mac in Coventry - I had GT6 prop shortened there).
  
  Van
  
  

  • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

    Posted By : Colin Wake, 21-Dec-2004, 04:16pm

    You can't change the input shafts over, different helix angle on the gears.
    
    You need a 1300 dolomite (or late 1300 Toledo) clutch friction plate and it will fit straight on inside the mk2 cover.
    
    You need to change the flange on the rear of the 1500 overdrive prop to match your diff, or get the non-od prop shortened and the front flange changed to match the gearbox.
    
    All easy stuff!!!
    
    Don't forget to work out what you will do about a gearstick and OD switch, especially if the gearbox came from a 1500 dolomite.
    
    I always think the top of the gearstick switch looks wrong in a 'roundtail'
    
    Colin
    
    

    • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

      Posted By : Tom Broome, 21-Dec-2004, 06:16pm

      
      Thanks Colin for the excellent information it has really helped me.
      
      I agree, the switch looks wrong on the gearstick so i am going to use the original overdrive switch on the steering colum.
      
      If anyone else has any more information please submit.
      
      cheers
      
      Tom Broome
      

      • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

        Posted By : Chris Taylor, 21-Dec-2004, 06:48pm

        Before purchasing a clutch plate, you need to know whether your Mk2 has a coil spring clutch (early cars, 6.25" diameter) or a later diaphragm spring clutch (6.5" diameter).
        
        There are suitable fine spline clutch plates available to suit the 1500 gearbox input shaft and 6.5" clutch (not sure whether it's a standard Triumph clutch, as I thought Toledos etc used the 3 rail gearbox and coarse spline input shaft, and the 1500cc cars used single rail gearbox with fine splines but a 7.25" clutch plate) but Canley Classics DO sell a suitable clutch plate for just this conversion. However I'm not sure that there is a plate available for the 6.25" coil spring clutch.
        On the Herald the change happened late 65 or early 66, but I have not seen definitive commission number or engine numbers quoted for a changeover, so you may have to take it apart to see.
        Although the flywheels for both clutches have the same bolts for both clutches, you cannot simply swap one for the other as they have different alignment dowels. So IF you have a diaphragm spring clutch, just buy a suitable clutch plate, and change propshaft as already explained.
        
        IF you have a coil spring clutch, you either need to get a later flywheel suitable for the 6.5" clutch (any later 1147 or 1296cc engine probably) and buy special clutch as above, or change direct to a 1500cc flywheel and use the standard Spitfire 1500 clutch which will match the 1500 gearbox with no problems. The larger diameter clutch will probably wear a little less, take more abuse etc, but the 1500 flywheel MAY be a little heavier (I'm not sure).
        IF YOU ARE CHANGING FROM COIL SPRING TO EITHER TYPE OF DIAPHRAGM SPRING CLUTCH, YOU WILL NEED TO CHANGE THE RELEASE BEARING AND THE SLAVE CYLINDER. The travel needed to release the two clutches are different.

        • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

          Posted By : William Davies, 21-Dec-2004, 07:57pm

          According to factory literature, the diaphragm clutch was introduced "from first production" of the Mk2 Spitfire, which I have to say surprised me.
          The "special" clutch plate to match the 1200/1300 engine with a single rail gearbox is GCP244, readily available for around £50.
          Cheers,
          Bill.
          

          • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

            Posted By : Jason Chinn, 21-Dec-2004, 09:09pm

            This all sounds like a chat to Karl or Dave at Canley Classics will get you the right answer - having done a couple of gearbox jobs with their bits I can honestly say that if it can fir, they will have done it and can supply you with the parts to complete the job - that includes my own 13/60 with single rail and J type overdrive and now the GT6 convertible change from coarse spline and D type to fines spline and J type. Both involved a change of clutch plate. The 13/60 plate is the same as a Marina 1300 item I think.

        • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

          Posted By : Van Hamlin, 21-Dec-2004, 08:01pm

          Sorry Tom, I had thought the input shafts might be interchangeable cos I have seen the same countershaft gears for both single and 3 rail boxes.
          
          Looking in the books it seems this only applies to late (MkIV spit) 3 rail boxes so Colin's probably right about them not being interchangeable.
          
          I also thought MkII's all had the diaphragm clutch?
          
          The 6.5" fine spline clutch plate might be a Canley special, because according to the TT book there was never such a clutch!
          
          Always remember what everyone (including me) says here assumes your car is still standard, but in a car nearly 40 years old there may well be some different bits you come across that have been changed along the way. So beware! but all this stuff is part of the challenge.
          
          Good luck
          Van
          

          • Found the DRIVEN PLATE 6 1/2 FINE SPLINE which is £49.50 for gearbox!!!!

            Posted By : Tom Broome, 21-Dec-2004, 08:39pm

            I think I have found the right Clutch plate availible at Canley Classics
            
            
            DRIVEN PLATE 6 1/2 FINE SPLINE which is £49.50
            
            This should hopefully work>
            
            Cheers
            
            Tom Broome
            
            
            Any more info would be great.
            

            • Found the DRIVEN PLATE 6 1/2 FINE SPLINE which is £49.50 for gearbox!!!!

              Posted By : Tim Willis, 22-Dec-2004, 06:18pm

              I'm sure this plate is the same as found on 1098cc Morris Minors and MG Midgets, so it might be worth trying suppliers for those as it isn't anything special for them.
              
              Tim
              
              WillowTriumph
              

        • will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

          Posted By : Colin Wake, 21-Dec-2004, 11:06pm

          Thanks Chris for the mention of the coil spring clutch, I had forgotten that early Mk2's had those, despite removing a couple in the last year from cars I have dismantled!
          
          Very late (p-reg) toledo's do have 6.5 inch clutches and single rail boxes, in fact I have a whole P-reg Toledo (with its single rail box) looking for a home if anyone is interested!!! Very Cheap!!!
          
          Colin

    • Where can i get clutch friction plate to fit inside the mk2 cover.

      Posted By : Tom Broome, 21-Dec-2004, 07:33pm

      Where can i get clutch friction plate to fit inside the mk2 cover.
      
      Does anyone know
      
      Cheers
      
      Tom Broome

• will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

  Posted By : Tom Broome, 21-Dec-2004, 04:09pm

  Thanks for the help.
  
  I'm going to have a go at changing the imput shaft over from the Mk2 Gearbox.
  
  many thanks
  
  Tom Broome
  
  If anyone else knows a way of doing it please send information

• will a 1500 spitfire gearbox and overdrive fit a Mk2 spitfire

  Posted By : Roger Owen, 24-Oct-2005, 10:34pm

  Hi Tom,
  
  Yes, they will fit - BUT........... You'll have to fit the appropriate shorter propshaft, and gearbox mounting plate (1500 type, with a little bit of re-drilling and welding). Also, if your are considering keeping the orig MkII 4.11 diff you will need to change the rear prop shaft flange to fit. Drop me a line, and I'll give you all the gen - as I'm actually in the process of same operation!!!
  
  Cheers,
  
  Roger Owen