Joe c Posted May 6, 2019 Report Share Posted May 6, 2019 Hello in the process of gt6 overdrive box to my vitesse mk2 ,now if I knew what I started so the main issue is gearbox approx 10cm longer had to cut propshaft tunnel back and possible trim sides slightly to get gearbox in but now in Now next issue is propshaft Or all over drive props the same or have to modify original or any issues I face has anybody done this thanks joe now Link to comment Share on other sites More sharing options...
Clive Posted May 6, 2019 Report Share Posted May 6, 2019 GT6 and vitesse overdrive boxes are identical (OK, some differences over the years and the last GT6 boxes were probably the best) But it means you just need the overdrive vitesse parts. So a vitesse overdrive prop (different to GT6) likewise vitesse overdrive cabe, and assume you have the angle drive for the cable? You must have the correct od rubber mount plus the overdrive mounting plate? And not sure what you are doing about switch, either the vitesse/early gt6 coulm switch, or the GT6 gearstick and switch depends on what is available and preference. My only concerns is that you have a proper vitesse/gt6 gearbox. It has the same gearchange mechanism as the one you took out? I hope so.... Link to comment Share on other sites More sharing options...
JohnD Posted May 6, 2019 Report Share Posted May 6, 2019 Shown this before, but it does away with the need for a column switch, by putting it on the steering wheel. The rocker switch shown later replaced by an ON-OFF-ON press switch and pilot light. Curlywhirly three core cable to the wheel, froma bracket under the dash. John Link to comment Share on other sites More sharing options...
johny Posted May 6, 2019 Report Share Posted May 6, 2019 Ive wondered about using one of those old triumph floor mounted switches you see so much on ebay to operate the overdrive. Would be pretty convenient if theres room next to the clutch pedal..... Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 45 minutes ago, clive said: GT6 and vitesse overdrive boxes are identical (OK, some differences over the years and the last GT6 boxes were probably the best) But it means you just need the overdrive vitesse parts. So a vitesse overdrive prop (different to GT6) likewise vitesse overdrive cabe, and assume you have the angle drive for the cable? You must have the correct od rubber mount plus the overdrive mounting plate? And not sure what you are doing about switch, either the vitesse/early gt6 coulm switch, or the GT6 gearstick and switch depends on what is available and preference. My only concerns is that you have a proper vitesse/gt6 gearbox. It has the same gearchange mechanism as the one you took out? I hope so.... Link to comment Share on other sites More sharing options...
thescrapman Posted May 6, 2019 Report Share Posted May 6, 2019 If you had said an inch longer, I would have said you have the long rear flange on a J-type or a single rail box from an 1850 Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 Yes changed mounting plate and rubber mount and angle drive for speedo only one concern with box it a 73 us spec don’t know any difference and overdrive solenoid on left hand side of car had a propshaft what measures up ok but flanges both end smaller don’t know if interchange flanges with original overdrive s/w just mount s/w under dash to test then make a decision Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 8 minutes ago, thescrapman said: If you had said an inch longer, I would have said you have the long rear flange on a J-type or a single rail box from an 1850 Hello I identify box as gt6 73 us spec basically 10 cm longer then original non overdrive now can any overdrive be bolted on see numbers but know J ,D or A type not j solenoid on left hand side of gearbox can u identify by numbers thanks joe Link to comment Share on other sites More sharing options...
johny Posted May 6, 2019 Report Share Posted May 6, 2019 Definitely not a D type overdrive but pics of the box and prop would be useful Link to comment Share on other sites More sharing options...
NonMember Posted May 6, 2019 Report Share Posted May 6, 2019 Solenoid on the left sounds like a J-type (I've not seen an A type on a GT6 box - is it even possible?) which should fit with a standard Vitesse OD prop, which is a couple of inches shorter than the non-OD one. But if the "new" box is 10cm (4 inches) longer than the old then that doesn't sound right at all. Could it be that the "GT6 73 US spec" box Joe has been sold is actually nothing of the sort but rather a Triumph 2000 saloon box? We can tell some of that from numbers. We can definitely identify it from a decent set of photos. Link to comment Share on other sites More sharing options...
Clive Posted May 6, 2019 Report Share Posted May 6, 2019 Indeed a picture is needed. Did teh GT6 box ever get the J type OD?? I know the early dolly 1850 is identical to GT6/vitesse box but with J type, and rebuilds can swap cases etc about. Pictures will definitely help. Link to comment Share on other sites More sharing options...
NonMember Posted May 6, 2019 Report Share Posted May 6, 2019 I'm pretty sure the J-type was never fitted on GT6 by the factory but, as @clive rightly says, the early 1850 box is identical so there are a lot of GT6 boxes out there with J-type now. Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 Hello here some pics of overdrive hope someone can identify it Link to comment Share on other sites More sharing options...
johny Posted May 6, 2019 Report Share Posted May 6, 2019 Yes that's a J type OD but I can't understand why it's so much longer than the original box when normally you would expect no more than 1" difference compared to the standard D type gearbox. The serial number stamped on the top RH side of the cast iron gear case would be useful to know as well.... Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 6, 2019 Report Share Posted May 6, 2019 Yes def 3 rail + J type , Please post the serial prefix on the top face of the main cast case. Pete Link to comment Share on other sites More sharing options...
johny Posted May 6, 2019 Report Share Posted May 6, 2019 Sorry just reread your previous post and see that this box is 10cm longer than original non OD box which of course is perfectly possible. So yes that gearbox looks like it's going to be the same length as a standard Vitesse OD one.... Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 6, 2019 Report Share Posted May 6, 2019 You will have to cut 4" off the prop tunnel to access the rear coupling bolts on a overdrive box in a herald/vitesse Guess same applies to GT6 and Spit. Pete Link to comment Share on other sites More sharing options...
thescrapman Posted May 6, 2019 Report Share Posted May 6, 2019 Very last GT6 had the J type I think, Same as last few Mk4 Spitfire got them. there are 2 different rear flanges available, 1 an inch longer. Also 2 different size OD to gearbox plates, again an inch longer. i think you got the longer rear flange if you got the shorter adaptor on an 1850, but if you fit the short flange to the short adaptor the normal OD prop will fit. Certainly did on my Spitfire. Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 Hello the d mounting plate doesn’t fit also the Propshaft measure 43 half inch fully in to tight to fit so checking overdrive definitely j type so now need j mounting plate also j propshaft which is shorter I hope or have to get propshaft cut only glad had propshaft only bought d mounting plate Link to comment Share on other sites More sharing options...
johny Posted May 6, 2019 Report Share Posted May 6, 2019 No Joe, as Scrapman says you just need the shorter rear coupling flange to get a standard OD propshaft to fit. In fact you should be able to use the one off your non OD gearbox and it's an easy job which should make your new box 1" shorter..... Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 Ok thanks I will try that tomorrow Link to comment Share on other sites More sharing options...
Joe c Posted May 6, 2019 Author Report Share Posted May 6, 2019 3 hours ago, thescrapman said: Very last GT6 had the J type I think, Same as last few Mk4 Spitfire got them. there are 2 different rear flanges available, 1 an inch longer. Also 2 different size OD to gearbox plates, again an inch longer. i think you got the longer rear flange if you got the shorter adaptor on an 1850, but if you fit the short flange to the short adaptor the normal OD prop will fit. Certainly did on my Spitfire. Ok thanks Link to comment Share on other sites More sharing options...
johny Posted May 7, 2019 Report Share Posted May 7, 2019 Please let us know if it works as these things are good to know🤓 Link to comment Share on other sites More sharing options...
Joe c Posted May 7, 2019 Author Report Share Posted May 7, 2019 2 hours ago, johny said: Please let us know if it works as these things are good to know🤓 hello see what u mean ,I was thinking maybe not enough clearance on mainshaft but looking at pics this could resolve it Link to comment Share on other sites More sharing options...
johny Posted May 7, 2019 Report Share Posted May 7, 2019 It should be a good gearbox as it incorporates almost all the improvements that Triumph made during the production of these cars👍 Link to comment Share on other sites More sharing options...
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