RobinTR6 Posted September 14, 2014 Report Share Posted September 14, 2014 Silly it may seem but which way does the speedo drive cable rotate when viewed from inside the car (my speedo has seized and broken the angle drive cable; I've got an old spare angle drive which seem fine but sticks if it drives the speedo cable anti-clickwise; I'm assuming that this is because the drive is clockwise; but dont want to reassemble to discover I'm wrong), as ever thanks. Quote Link to post Share on other sites
AlanT Posted September 14, 2014 Report Share Posted September 14, 2014 (edited) If you just flick the end of the cable round in the right direction a bit, you will see the gauge jump up. I am repairing four right angled drives at this moment. I know all about them now. There are lots of marginal design features with the speedo cables and drives. Miracle it ever works really. I just found a way to make replacement stub-cables. Please post a picture of yours. Or tell me if its an original Smiths one. Remember that the drive is spurred from the prop shaft and so the right-angle drive goes the other way when you reverse. It's no good if it jams in reverse because this will break the stub cable. Lots of pictures of the inside of drives and other stuff in this topic: http://www.tr-register.co.uk/forums/index.php?/topic/47968-pesky-right-angled-drives/ Edited September 14, 2014 by AlanT Quote Link to post Share on other sites
AlanT Posted September 14, 2014 Report Share Posted September 14, 2014 Here is a new stub-cable for a Smiths drive: https://flic.kr/p/oVF5XH There will be a new topic on this matter in a while but this is a "taster'. Cable material appears by courtesy of "Lebro". Quote Link to post Share on other sites
peejay4A Posted September 14, 2014 Report Share Posted September 14, 2014 Robin, If you imagine how the cable has to drag the needle round you can work out that it should go clockwise when viewed from the drivers seat. Quote Link to post Share on other sites
AlanT Posted September 14, 2014 Report Share Posted September 14, 2014 You may like this: http://www.ebay.co.uk/itm/TRIUMPH-GT6-VITESSE-SPITFIRE-DOLOMITE-OVERDRIVE-ANGLE-DRIVE-SPEEDOMETER-SPEEDO-/390874823689?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5b01f47c09 Quote Link to post Share on other sites
RobinTR6 Posted September 14, 2014 Author Report Share Posted September 14, 2014 (edited) Alan, you probably didnt notice my speedo is jammed solid so cant rotate the cable once located in it, this is why the angle drive cable broke (I assume). I have 2 angle drives, the broken one and the one that doesnt go anticlockwise. The drive pinion from one doesnt seem to fit in the other so I'm a bit stumped. heres some pics Edited September 14, 2014 by RobinTR6 Quote Link to post Share on other sites
AlanT Posted September 14, 2014 Report Share Posted September 14, 2014 Makes no difference. They must work in both directions. So you need to fix 'em or get another. I would not bother with repros. The original Smiths ones are vastly better than the two repro ones I've dismantled. The Bastuck one was especially poor. It's OK now though!! New main bearing shells required, 35 thou play: https://flic.kr/p/oVHDxX Quote Link to post Share on other sites
RobinTR6 Posted September 14, 2014 Author Report Share Posted September 14, 2014 Ok , neither of mine says Bastuck but thers no markings on either so cant tell. I'm not equipped to repair them. You said you were fixing 4 of these would you consider fixing mine ? (obviously I'll be happy to pay for the work etc), then I'd have a spare. My only concern is that if the drive gear from the unbroken one doesnt fit in the broken one does this mean that the unbroken one wont drive the speedo accurately ? Quote Link to post Share on other sites
AlanT Posted September 14, 2014 Report Share Posted September 14, 2014 Can't tell a lot from these pictures. The one on the left looks as if it may be an original for a TR6. If it has a true "cheese-head" screw then it probably is. A 4A original has a brass knurled nut. I think the original Smiths ones were all made without circlips. Did you have to remove peening to dismantle one of these? None of the gears of these interchange between different manufacturers. There are always minor variations in diameter and length which result in a bad fit. But I think they all have the same "gear ratio". So probably any one you buy will fit and read the same speed. Quote Link to post Share on other sites
RobinTR6 Posted September 16, 2014 Author Report Share Posted September 16, 2014 Thanks all, Alan you have a PM response and thanks. Quote Link to post Share on other sites
RogerH Posted September 16, 2014 Report Share Posted September 16, 2014 Hi Robin, this will not help you but will give you something to read during a stress break!!! When I had my gearbox out the other week I also had a problem that the speedo had stopped working (or bouncing). I found that the speedo end of the cable was a fraction short and only just locating in the speedo square hole. This put excess pressure on the small area of contact and had become rounded. The new cable was apprx 1/16" longer and gave better engagement. By chance I noticed that the input to the angle drive could be pushed in and pulled out quite a lot. When pulled it gave very good engagement of the bevel gear. When pushed in it would miss the odd tooth. Off with the end cap and a packing washer inserted. The speedo now works perfectly (unlike the rev counter) Roger Quote Link to post Share on other sites
AlanT Posted September 16, 2014 Report Share Posted September 16, 2014 No control of pinion end-float. Typical repro problem. Quote Link to post Share on other sites
AlanT Posted September 25, 2014 Report Share Posted September 25, 2014 (edited) These two drives arrived this morning. One had a broken wire and is otherwise a good quality part. Not the best but useful. Its fixed now: https://flic.kr/p/poywQQ The one that only turns one way interested me. How can this be? Well this is the bevel-gear: https://flic.kr/p/p765WS The teeth of this have not been produced by grinding! The this is just a casting. This makes teeth with way too much friction for proper turning. This is really cheap "repro engineering" because production gear hobbing on a part like this is quite quick. I will try to smooth this and make it useful. An original Smiths one looks like this: https://flic.kr/p/pjAjsN and is so smooth it will turn in the breeze. Edited September 25, 2014 by AlanT Quote Link to post Share on other sites
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