Adrian Saunders Posted May 31, 2019 Report Share Posted May 31, 2019 Anyone else had issues with a new speedo cable for GT6 mk3 with overdrive? Please see attached picture, the black one is the new one. The end fittings are wrong: too small at the od 90 degree drive and too big at the rear of the speedo. Link to comment Share on other sites More sharing options...
Mad4classics Posted June 1, 2019 Report Share Posted June 1, 2019 Think the black one is actually a tachometer cable. Have you tried the fit on the distributor? David Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2019 Report Share Posted June 1, 2019 There is some evolution on cables over the years And the drive squares change size as the design gets younger therenis also a flattened end which drives from the diagonals Both speedo and rev counter use the same smiths drivehead the variance will be agism not whether its speedo or tacho Best place would be speedy cables , send it back as incorrect stock to model Pete Link to comment Share on other sites More sharing options...
NonMember Posted June 1, 2019 Report Share Posted June 1, 2019 This may sound like a really dumb question but... is it just the wrong way round? Tacho cables are the same fitting at both ends, I think. Later (1500 / Dolomite) speedo cables have completely different fittings. Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2019 Report Share Posted June 1, 2019 Donsnt the head end inner normally have a crimp on ferrule to control its position , so it only fits one way ?? IE you can only withdraw the inner from the head end ??? Or is that a dream Do make sure you have a 7/16" simple washer between angle drive and speedo pinion to make sure there is not pre load on the angledrive primary drive. Pete Link to comment Share on other sites More sharing options...
Mad4classics Posted June 1, 2019 Report Share Posted June 1, 2019 The tachometer cables I've got are a different size inner and fitting to the speedo; they're not interchangeable. Even though internally when you look at the frame head they're almost identical. The inner on the tachometer measures 0.1 " square and on the speedo 0.125" square. The Delco Remy drive is 0.1". Both have a crimp on ferrule at the head end. The tachometer in the picture is Triumph whilst the speedo head is Mini - but this has the same fitting as the Triumph speedo, got it out to check. David Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2019 Report Share Posted June 1, 2019 like the bungy and Zeus an always useful pocket bible Pete Link to comment Share on other sites More sharing options...
NonMember Posted June 1, 2019 Report Share Posted June 1, 2019 7 minutes ago, Mad4classics said: The tachometer cables I've got are a different size inner and fitting to the speedo; Ah, I see what you mean! So the black cable appears to have a smaller inner than the grey one, but both of them have two different knurled nuts, whereas the tacho cable on my Spitfire (the last one I changed) has large knurled nuts at both ends. I'm pretty sure I have seen the small inner on a speedo cable for a Mk2 Spitfire, so maybe that was something they changed in the mid-60s? Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2019 Report Share Posted June 1, 2019 before they went to clip on orrible things . my 2000 has a small knurled nut, head end an thats a mind of its own , long fingers no room, always add a tyrap to the outer so the nut doesnt slide all back down the cable just as you need to twiddle it Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted June 1, 2019 Report Share Posted June 1, 2019 32 minutes ago, Pete Lewis said: before they went to clip on orrible things . Very handy for fitting, as I found on the TR7 - just plug in, and no fumbling about trying to start threads and tighten things up under the dash. Removal is a completely different kettle of fish, but then I don't suppose they had that in mind at the start. Link to comment Share on other sites More sharing options...
Mad4classics Posted June 1, 2019 Report Share Posted June 1, 2019 47 minutes ago, Pete Lewis said: like the bungy and Zeus an always useful pocket bible Pete Pete, Have had the Zeus book a long time, one of the first things on the list I was given to buy before starting my apprenticeship. The companies whose logos are on the back are long gone. David Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 1, 2019 Report Share Posted June 1, 2019 mine too all aircraft logo's mine was in 1962 and still going and used much historic doodling but Im truck not aero. Pete Link to comment Share on other sites More sharing options...
Adrian Saunders Posted June 1, 2019 Author Report Share Posted June 1, 2019 13 hours ago, Mad4classics said: Think the black one is actually a tachometer cable. Have you tried the fit on the distributor? David Top marks to you David. It is indeed a tacho cable. I’ll keep it anyway as I’ve already fitted the grommet for the bulkhead. Link to comment Share on other sites More sharing options...
Adrian Saunders Posted February 7, 2020 Author Report Share Posted February 7, 2020 On 01/06/2019 at 09:47, Pete Lewis said: Donsnt the head end inner normally have a crimp on ferrule to control its position , so it only fits one way ?? IE you can only withdraw the inner from the head end ??? Or is that a dream Do make sure you have a 7/16" simple washer between angle drive and speedo pinion to make sure there is not pre load on the angledrive primary drive. Pete Just a standard thickness, plain washer? Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 7, 2020 Report Share Posted February 7, 2020 yes even a fibre will work , if you read on rimmers they offer no warranty if no washer but find it listed if you can, there is a BL tech note advising this must be fitted ( on here somewhere) or the primary input gets pre loaded and the drive fails, Pete Link to comment Share on other sites More sharing options...
Adrian Saunders Posted February 7, 2020 Author Report Share Posted February 7, 2020 Thanks Pete. Max protrusion of square section is 3/4” on new cable and 15/16” on one that I’m replacing. The difference is greater than a washer? Pictures attached, on seat is new, on tunnel is old. Link to comment Share on other sites More sharing options...
Peter Truman Posted February 7, 2020 Report Share Posted February 7, 2020 Pete Lewis has just given great info on how to reduce or extend the inner cables protrusion by shortening or stretching the outer cable refer "Engine-New Noise- Pete Lewis post today". The method is to grip the outer and twist the spiral winding clockwise or anticlockwise to achieve the inner protrusion required. Buried that one in the back of my memory Pete to be shared with other club members, thanks. Peter T Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 7, 2020 Report Share Posted February 7, 2020 strangely this fix came about on the production line , cabs would be hoisted across from the cab line and if not hooked out the way the speedo cable could get caught on the conveyor track and by the time the chassis caught up with the cab ready to drop on the cable got pulled and stretched ended up with insufficient inner to drive the instruments , the twist the case rectification came from all this a better fix than route a replacement . simple really pete Link to comment Share on other sites More sharing options...
Adrian Saunders Posted February 7, 2020 Author Report Share Posted February 7, 2020 Fantastic. Sounds like a solution. If we could ascertain the ideal protrusion/engagement then we could all have perfect installations. I have 3/4” & 15/16” protrusion which feels ok, what do others have? Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 8, 2020 Report Share Posted February 8, 2020 thread drift off to the dark side seems inevitable 10 hours ago, Adrian Saunders said: 3/4” & 15/16” protrusion which feels ok, what do others have? Link to comment Share on other sites More sharing options...
dougbgt6 Posted February 8, 2020 Report Share Posted February 8, 2020 “thread drift off to the dark side seems inevitable” I don’t have protrusions, I did think about instaling a new unit, but those days are gone. (will that do?) db Link to comment Share on other sites More sharing options...
Pete Lewis Posted February 8, 2020 Report Share Posted February 8, 2020 you can new ones ....tell us more Pete Link to comment Share on other sites More sharing options...
johny Posted February 8, 2020 Report Share Posted February 8, 2020 yes but you have to be careful the surgeon puts it in the right place... Link to comment Share on other sites More sharing options...
Colin Lindsay Posted February 8, 2020 Report Share Posted February 8, 2020 7 hours ago, Pete Lewis said: thread drift off to the dark side seems inevitable I must admit I looked at that post and thought: 15 or 16 inch protrusion.... hmmmm. I reckon it would probably feel okay. Not offering, though. Link to comment Share on other sites More sharing options...
Adrian Saunders Posted February 8, 2020 Author Report Share Posted February 8, 2020 Link to comment Share on other sites More sharing options...
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