johny Posted May 18, 2020 Report Share Posted May 18, 2020 The 1600 had different ratios to the 2L especially 1st but I suspect that unit could be from a 1300 or 1500 Dolomite or similar. You could count the ratio if interested.... Link to comment Share on other sites More sharing options...
Nick Jones Posted May 18, 2020 Report Share Posted May 18, 2020 That is a single rail 1850 box built into a three rail casing. Will have the larger mainshaft tip and same ratios as Vitesse 2L/GT6. Only downside is it’s 1” longer meaning a shorter prop is needed (guess you have that) and it’s a very tight fit at the rear so a little chassis relief may be needed for the speedo drive. Nick Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2020 Report Share Posted May 18, 2020 I echo Nick , its not an unusual mix and match to get the best of the rest Pete Link to comment Share on other sites More sharing options...
KevinR Posted May 18, 2020 Report Share Posted May 18, 2020 I'm just wondering what the source of the actual gearbox housing is. The DC prefix is not one that was used on a Triumph, so what other BLMC cars used a 3 rail casing with the DC prefix. I suspect that the AAW stamping was put on by whoever built the box. The annoying thing is that I used to have a very similar gearbox in the garage, but I sold it with one of my GT6's about 4 years ago. I never got round to fitting it, so I never noted its serial number or prefix. If I recall correctly it was built by someone in East Anglia. Link to comment Share on other sites More sharing options...
NonMember Posted May 18, 2020 Report Share Posted May 18, 2020 1 hour ago, Nick Jones said: That is a single rail 1850 box built into a three rail casing. If that were the case it would have the fine spline input shaft. The last photo shows a coarse spline one. Link to comment Share on other sites More sharing options...
johny Posted May 18, 2020 Report Share Posted May 18, 2020 I'm wondering if that DC is really DG.... Link to comment Share on other sites More sharing options...
NonMember Posted May 18, 2020 Report Share Posted May 18, 2020 7 minutes ago, johny said: I'm wondering if that DC is really DG.... I wondered that but it doesn't look like a poorly stamped G, it really does look like a properly stamped C. Link to comment Share on other sites More sharing options...
ahebron Posted May 18, 2020 Report Share Posted May 18, 2020 This is great stuff. When I first fitted the gearbox many years ago I commented on a Triumph forum that the gearbox seemed to be too long but was firmly told it couldn't be so that is now sorted. And yes it is a bugger to get out, I had to cut a small section of floor by the solenoid to get it out and bend back the tunnel to clear the speedo drive. As it was built for a GT6/Vitesse as per the white marker pen then they would have fitted the correct input shaft. If I remember tomorrow I can take the cover off and get a photo of the internals if anyone is interested. Looking at the C stamped in the gearbox the bottom arc of it seems short so maybe it could be G but as this is a mongrel box does the housing number matter. I am building a new mount that will make it easier to remove as the one I made when I first fitted it does not allow easy removal with the body and exhaust fitted. Excuse the red paint that was when I had to remove powder coating that had spider rust underneath it. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2020 Report Share Posted May 18, 2020 the internals or 3 rail 4sync. and single rail all look the same its the mainshaft you cant see that has different spline and spigots the rest is of pretty much the same or very similar slight design changes what you dont get is the awful spool shuttle gear selector of the single rail design. it was good enough for Marina and MG/spit 1500 but not a real fan of Triumph who reverted to 3 rail on most remaining models of the type Pete Link to comment Share on other sites More sharing options...
Nick Jones Posted May 18, 2020 Report Share Posted May 18, 2020 2 hours ago, NonMember said: If that were the case it would have the fine spline input shaft. The last photo shows a coarse spline one. Well, it’s clearly using an 1850 mainshaft, OD adapter plate and OD. I suppose the same parts could also be sourced from a single rail Spit /Dolly 1500. The adapter housing is the giveaway, being visibly longer. Presumably the coarse splined input shaft has been machined out for the bigger bearing. Hopefully they also addressed the lubrication issue which is a big factor on the bearing failures IMO. Who knows about the rest of the gearset. Expecting case markings to give any reliable information about the content is optimistic. The youngest of the three rail boxes is 45 years old and as they were woefully under specified from the factory, almost all will have been through multiple rebuild cycles, and contain whatever the rebuilder was able to find. Nick Link to comment Share on other sites More sharing options...
Clive Posted May 18, 2020 Report Share Posted May 18, 2020 Makes me wonder.... did somebody make a special input shaft? I am not certain teh gear on that will mesh with single rail gears. Though no expert.... And a curveball. I know of a spitfire that for the last 100K has been driving around with a GT6 box, but the input shaft was chopped and a spit splined end welded on. Done by somebody who knows what they are doing, otherwise it would have died by now. Not sure it would last on a 6 cylinder, but you never know..... The point is, just enjoy the car when the box is back in. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2020 Report Share Posted May 18, 2020 mike papworth had some stem gears modified for 10 spline and 18mm spigot as we fitted one of his mainshafts and inputs to the Vit6 pete Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 18, 2020 Report Share Posted May 18, 2020 3 hours ago, Nick Jones said: all will have been through multiple rebuild cycles, and contain whatever the rebuilder was able to find. i got a box as a core unit think from ??? it had a brand new single rail 1st/2nd hub on 3 rail mainshaft and a reverse with more teeth than you could mesh this is where i found the hub only looks similar the splines are a rattling good fit on the mainshaft someone paid a lot of ££s for a non working hybrid mix and not match then i found its mainshaft spigot had been cut off and a nicely ground slug loosely fitted into a bored out mainshaft being loose had wrecked the input shaft bore so what you find inside can be more surprising than just wear and tear Pete Link to comment Share on other sites More sharing options...
Nick Jones Posted May 18, 2020 Report Share Posted May 18, 2020 5 hours ago, Pete Lewis said: mike papworth had some stem gears modified for 10 spline and 18mm spigot as we fitted one of his mainshafts and inputs to the Vit6 pete I got one bored out for the GT6 last year to go with one of Mr Papworth’s large tip mainshafts. The bore was knackered anyway. Put a sleeve and a roller bearing in it. Also got a hole drilled through the root of the gear to the back of the bearing so the meshing gears will force feed oil through. Bit on the gearbox rebuild here. http://sideways-technologies.co.uk/forums/index.php?/topic/7535-nick-chriss-gt6-mk-3/page/7/#comments One of the boxes I took apart looking for usable parts had a loose slug as a mainshaft tip. It hadn’t failed..... but I don’t think it had had much use. Nick Link to comment Share on other sites More sharing options...
ahebron Posted May 21, 2020 Report Share Posted May 21, 2020 Cleaned the gearbox inside and out and took the sump off the overdrive to give that a clean. It looks like the gearbox has been used but as I bought it along time ago I cannot complain. Some fine metal on the magnetic drain plug but no bronze or big pieces of metal came out so fingers crossed, all the teeth are where they should be and look ok. I made a new mount out of 25mm box section along the chassis using the original bolt holes and I welded compression tubes for the bolts. Across the rear end I bolted a 50mm x 10mm plate with a slot in it underneath the box section. I also bolted a 25mm box section under the gearbox mount to do this I welded a 10mm deep plate across the inside and drilled and tapped it. On the underside of this I welded another 10mm plate with a drilled and tapped hole in the middle so removal of the rear mount is easier than fiddling with the two mount bolts. That extra length makes things a bit challenging! To refit I also cut out more of the tunnel to get the rear of the gearbox down to line up with the engine. The reason for making the mount like this is I didn't have an original mount and I can access the whole length of the gearbox and overdrive underside without having to remove the mount plate Started bolting up the box to the engine and got the passenger side done but will need to move the car sideways and up to do the rest. The car is stored tight to my garage shelves and is on wheel jacks so I pull it out then use my scissor hoist to lift it. Then I went 'bugger' as I stripped the threads on the clutch slave cylinder mount. Tomorrow I will look into possibly helicoil-ing the holes but drilling looks a bit tight due to the clutch arm being in the way. Plenty of ways to skin a cat. Adrian Link to comment Share on other sites More sharing options...
Graham C Posted May 21, 2020 Author Report Share Posted May 21, 2020 Adrian, have you checked the length of the slave cylinder, as these may be shorter than the depth of the bolt hole, so with a longer bolt you can pick up on good thread. Just an idea, May save you an extra job. Graham Link to comment Share on other sites More sharing options...
ahebron Posted May 21, 2020 Report Share Posted May 21, 2020 8 minutes ago, Graham C said: Adrian, have you checked the length of the slave cylinder, as these may be shorter than the depth of the bolt hole, so with a longer bolt you can pick up on good thread. Just an idea, May save you an extra job. Graham Thanks Graham but yes all I see is clean holes, I could drill the holes out and tap it with UNC or maybe make some stepped studs. I am used to doing extra jobs on this car so hopefully when I do my Mk2 Convertible I will have made all the mistakes on this one and the last one. And to be honest its more fun than working😉 Adrian Link to comment Share on other sites More sharing options...
Graham C Posted May 21, 2020 Author Report Share Posted May 21, 2020 NOOOOOOO, everyone says that I as sit at the dining room table tapping away on a laptop look out at lovely weather and people walking around. Graham Link to comment Share on other sites More sharing options...
ahebron Posted May 22, 2020 Report Share Posted May 22, 2020 Got the clutch slave cylinder mounts helicoiled today. To make the holes an appropriate size I used a dremel flexi drive with engraving cutter tool and gently took the metal out till I could snugly fit the helicoil drill into as a reference. Tap, fit the helicoil and bolt up. Nick I didnt need to trim the chassis but I did cut more out of the transmission tunnel to clear the speedo drive on the right and the solenoid on the left, that extra inch in length is a bugger. Oh err missus. Link to comment Share on other sites More sharing options...
ahebron Posted June 3, 2020 Report Share Posted June 3, 2020 Photo of my gearbox mount Adrian Link to comment Share on other sites More sharing options...
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