NDP

Actually the retro fitting of a post 20k diff to a Roto GT6 could quite possibly be the exact problem here. I know the 3.27 diff has 6 stud holes. Does that definitely make it a post 20K diff? If so my GT6 (1972) is a pre 20K vehicle. Johny seems adamant that the 3.27 diff for a Rotoflex should have six holes. Looks like this problem is set to rumble on. Any more input chaps?

Would it be problematic to fit a six stud case to a rotoflex car?. Why I ask is because prior to owning the car the original 3.27 was replaced by a 3.66 I believe. I am in the process to installing a 3.27 taking it back to originality and then came across the two types. Hence the issue I have. Advise from anyone with any knowledge in this are would be much appreciated (including where I may be able to contact you directly for a chat about the issue). Kind regards.

Hopefully someone from the technical side can help me with this. Some time ago I purchased a 3.27 diff for my Triumph GT6. I was going to get it refurbished and put onto my car, which would bring it back to original. However, I now realise the diffs fall into two categories, up to KE/KF200000 and above. My GT6 fits into the "up to KE/KF 200000" category but I have no idea which category my purchased diff belongs to. So my questions are: 1). Is there an easy way to identify which category my diff belongs to? 2). Would it cause problems if the diff was a KE/KF 2000001+ diff and I had it fit to the car? Any help / pointers much appreciated.

Thread closed, I have now found one, thanks to Dick Twitchen.

Great news, Dick has one in his shed, deal done. A little job of refurbishment over the Autumn and hopefully all up and running for next Spring.

Pete, unfortunately, I think the grease nipples on my trunnions have also been pumped full of grease by the chap at the local garage (I must admit I would probably have done the same). What do you suggest I do now? Should I have them taken off and stripped down, degreased and refilled with oil, or don't you think it will cause any serious damage?

I would take an old scrap part or a fully refurbished part. If it is fully refurbished, I would need photographs and guarantees. If it is a spare / scrap part I would take it in any condition as long as the case was not cracked or damaged in any way. Please pm me. Regards NDP.

Thank you all for your input. If anyone comes across a lead that may uncover a 3.27 I would appreciate a heads up. Once again, thanks to all.

I just know somebody somewhere will have one laid in the back of a shed / workshop and would rather get a couple of hundred for it in the knowledge that it is going to make an old Triumph back to its original spec again, than let it rust away where it is! Fingers crossed.

Chris, yes I have seen it but lets be honest it needs a full referb and the price that is being asked is way too high to make it economically viable. For something in that condition I would only go up to £200.

Nigel, thanks for the info and link to 2Spec.

Cheers Pete. This confirms my fears that I have to go back to my search for a 3.27.

Having a horrible job tracking down a 3.27 diff (at a reasonable price if it need rebuilding), so I was wondering if a 3.89 diff could be converted to 3.27 by exchanging the crown and pinion wheels? Something tells me this probably isn't possible otherwise more people would do it rather than search for a complete diff. Second part of my enquiry is: If adding a LSD unit into the diff, does it replace everything apart from the crown and pinion wheels?

Gents, thank you for all the information / suggestions. I have had my gearbox refurbished so am reluctant to now exchange that out for an OD unit (plus the car didn't originally have one). The thing that worries me is all the talk of 3.27 diffs failing. I would hate to spend a bucket full of money and then discover that it failed. However, I would be surprised if it did fail because I don't exactly thrash the car when driving it and I never take it to track meetings etc. Is there some inbuilt known faults with the 3.27 that cause it to fail with normal use? If I bought one that needed refurbishing what are the views of having a LSD incorporated into it? (MLR or Quaife). Would this cure any weak points in the diff? Cheers, Neil.

Thanks Rob, that is a relief. All I need now is to trasck down a 3.27 diff! Cheers, Neil.

Hello, I have a 1972 Triumph GT6 MKIII non-overdrive. Prior to my ownership someone has exchanged the 3.27 diff for a 3.89 one. I am in the process of trying to change it back. I have removed the prop shaft and sent it for reconditioning but then I have had a worrying thought. Presuming that both diff's were original Triumph diffs (and not altered in any way from the original specification) would the prop shaft be the same for both differentials?. The gearbox has not been changed and remains a non-overdrive box with original specification. I would also be interested in hearing from anyone who has a 3.27 diff for sale. Cheers, Neil.

Excellent gents. Confirmation that my routing is incorrect and by re-routing it another snag should be sorted. Many thanks, NDP.

Thank you for that posting. I see you also have the bracket for the drivers side ignition illumination light. I have been trying to get hold of one of those for years. I'm now green with envy! So, from what you are telling me both my speedo and tacho are routed incorrectly. This is frustrating but great to know. This may well solve the issue, but no doubt will lead to many hours of fiddling around behind the dash! Once again thank you all for your suggestions and illumination. Back to grovelling under the GT for me. Cheers, NDP. PS. Are any of you chaps going to the Stratford show in August? I have never been but thinking of driving the car down there for the weekend.

I have been looking at a few engine bay photos online and they seem to be routed differently to mine. All are RHD, the same as mine but the tacho cable appears to be going through the bulkhead at the battery side, not routed behind the engine and then through the bulkhead behind the airbox. If the routing on mine is correct then I can only think that the cable is too short and it is back to finding out what length the original cable was. Pete, I understand that your suggestion would solve the issue but I would prefer to try to keep the dial layout original if I can. Regards,

Pete - The tacho is in the right hand side of the RHD dashboard. Standard I think for a 1972 MKIII GT6? Jim - This is where the tacho cable goes through the bulkhead. Hopefully these pictures show the route. Regards,

Hello, I wonder if anyone can help with this. During a rebuild of my GT6 MKIII I had an electronic ignition system put in. It is in exactly the same position as my old manual system but the cable to the rev counter was also replaced. Subsequently trying to get the advance / retard on the car has been a problem because the cable seems to be very tight and the distributor cannot be moved much. My question is this: What length should the tacho cable be? I ask this because I am a little suspicious that aftermarket replacements may be a bit shorter or they may have fit the wrong cable by some chance? Any guidance much appreciated. NDP

I thought I would post a final update on this topic because of how frustrating it has been for me to find a cure and hopefully this helps someone else short cut the problem. Since my last post I did the following: 1). Get a 3mm gasket (has to have one made but cost was negligible). Didn't cure the issue but it did make a difference when I measured the fuel pressure with a gauge I bought. 2). Had a 2mm gasket made and connected together with the 3mm gasket ( For those of you asking why I didn't get a 5mm gasket made, they only make the "Unigraph Unimetal sheets in 1, 2 or 3mm that the gasket was cut from). When fit this cured the problem. Fuel pressure was reduced to 2psi (but only when up to running temperature, prior to this it hardly registered on the psi scale). Once again for all of those that put forward suggestions, thank you. The full rebuild of my GT6 is ongoing and I have a few more questions / issues for which I will open new threads. Kind regards and keep motoring!

Cheers Jim!

Thanks one again chaps. Stratton, when you said extra space between the pump and block, just how much extra space are you talking about and did you have specific gaskets in mind?