MarkB Posted March 28, 2011 Share Posted March 28, 2011 About three years ago I sourced what I thought were the parts needed to fit a 1500 J type box onto a 1300 small crank engine I've had sat in my garage for about 20 years. I found a 6.5 clutch plate at an auto jumble with the fine spline that matched that of the 1500 box. I can't remember where the pressure plate came from but it was new and I am sure must be a 1300 spit Item? Anyway mated the two together and then got side tracked on Vitesse and GT6 projects. The other day I whipped out the engine and box from my MK3 Spit and put this combo in place. I had a feeling that the clutch may have stuck after sitting for three years so before bolting everything up I connected the slave cylinder and tried the clutch pedal. It went down half an inch and then went solid. Both cylinders were working fine so pulled out the engine and removed the box and clutch which had rusted itself to the cover plate and flywheel. Cleaned up perfectly as was only surface rust. When I first saw the cover plate I noticed that the diaphragm segments where flat, and I always thought they pointed out slightly away from the flywheel, and only went flat or pressed in when you depressed the clutch and the release bearing pressed the segments in. As I unbolted the cover, which was under tension the segments sprung out. After cleaning it all up bolting the clutch and cover back onto the flywheel as soon as the bots were tightened the cover plate segments started to move in again. Engine and gearbox back in car press the clutch pedal which moves a little and then goes rock solid. I can only thing the clutch plate is to thick, so effecting the cover plate when bolted up tight, so when I press the clutch pedal the segments on the clutch cover has nowhere to go. From memory I think the clutch plate was from a marina, and am sure I would have compared it for thickness at the time. If any of this makes sense what do you think?CheersBlue Link to comment Share on other sites More sharing options...
Howard81 Posted March 28, 2011 Share Posted March 28, 2011 Two clutches sizes were used on Spitfires:6.5" = 1300 engine7.5" = 1500 engineTwo different splines were used on three and single-rail gearboxes:10-splines = three-rail gearbox20-splines = single-rail gearboxSpitfire IV (1300) had the three-rail gearbox, so the clutch would be a 6.5" / 10-spline unit.The Spitfire 1500 had the single-rail gearbox, so the clutch would be a 7.5" / 20-spline unit.Yours is a hybrid of both of the above! This is for UK spec cars - in the US they had the 1500 engine few years before us combined with the three-rail gearbox.You need a 6.5"/20 spline clutch.. which was used on the following cars:1975-1980 Triumph Dolomite 13001975 Triumph Toledo1970-1971 Morris Marina 1300Part number is GCP244. Link to comment Share on other sites More sharing options...
MarkB Posted March 29, 2011 Author Share Posted March 29, 2011 Thanks for the infoThe plate I used is 6.5"/20 spline clutch, and believe it was for a marina, thats why I didn't expect any problems, but somethings not right.Cheers Link to comment Share on other sites More sharing options...
sparky_spit Posted March 29, 2011 Share Posted March 29, 2011 Blue - I have the same setup as you at present - 1500 single rail box and 1300 FD engine. I use a Toledo clutch and it works fine. Looking at your picture, as you say, it seems like the plate is too thick, or not seating properly. When you look closely, I assume the plate is in contact with the flywheel surface? It's not something silly like the plate being put in back to front? Link to comment Share on other sites More sharing options...
Nick Jones Posted March 29, 2011 Share Posted March 29, 2011 Do you still have the coarse splined clutch plate so you can compare the thicknesses? Or even try it in there so you can check all works? If the original plate is not new, bear in mind it may be worn down.Normally you can get away with swapping plates around but I do agree that those clutch fingers look a bit too flat. Probably doesn't need the friction lining thickness to be much greater to cause problems. May be more of a problem of mixing and matching parts from different clutch manufacturers than anything else. Certainly I have successfully mixed Herald/Spitfire covers with 1300 Dolly friction plates in the past.Nick Link to comment Share on other sites More sharing options...
Richard B Posted March 29, 2011 Share Posted March 29, 2011 Yes you want the 1300 Dolomite friction plate, and yes something looks wrong! Link to comment Share on other sites More sharing options...
MarkB Posted March 29, 2011 Author Share Posted March 29, 2011 Removed the engine and gearbox for the third time and compared clutch plate and cover with the ones from the large crank 1300. There where differences with the cover plate, and when I measured the depth the marina clutch plate with another I had, the centre part of the clutch was 25mm, 3mm deeper than the other, the 22mm deep marina plate matched the depth of the original Spitfire one. This new marina clutch plate wouldn't fit in the centre of the new clutch cover so I used the part worn Spitfire. The clutch now operates. Can't pin point the exact cause but probably due to the overall depth of the spline being 3mm to deep.CheersBlue Link to comment Share on other sites More sharing options...
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