Mk2 Chopper Posted April 29, 2019 Report Share Posted April 29, 2019 Hi guys, Hope those of you who got out for drive it day yesterday had fun. On the way home my speedometer stopped, I've just had a chance to look at it and pulled the speedo cable and it appears to me that the plastic bush has moved so that the square end can't engage with the speedo drive (I can't move this bush by hand). It looks chamfered like the opposite end and I can tell there isn't a snapped off end still in the speedo. Am I correct and if I need to order a new one can I just measure the inner cable length? Gareth Quote Link to post Share on other sites
harrytr5 Posted April 30, 2019 Report Share Posted April 30, 2019 External length of the cable would be the one to measure and then the internal would be the right length. There is a couple of **** repros out there so be careful. Regards Harry TR5 Nutter Quote Link to post Share on other sites
Mk2 Chopper Posted April 30, 2019 Author Report Share Posted April 30, 2019 My thinking was to leave the outer part and fit a new inner, I think the two lengths are something to do with if you have an over drive fitted or not. Anyhow I've managed to force the plastic part down with some effort so I'll see how that goes and keep an eye on a replacement. Gareth Quote Link to post Share on other sites
keith1948 Posted April 30, 2019 Report Share Posted April 30, 2019 Hello Gareth To me it looks like the plastic bush has jammed inside the knurled cap that holds it into back of speedo. The cable has continued to turn and 'unwound' the plastic bush. The plastic bush should fit inside the knurled cap but to get the position right first make sure the cable is properly pushed in as far as it will go (so it fully engages at the gearbox end). A thin smear of silicone grease on the plastic or a drop of thin 3 in 1 oil would be enough to stop it binding again. Also the knurled nut only needs to be finger tight. Your cable looks 'dry' compared to mine. Pull the cable out a couple of inches and if the inner cable doesn't spin easily by hand inside the outer then a touch of lubrication is required. People have their own views on what to use but I prefer a thin smear of a thin oil like 3 in 1 oil on the cable (withdraw cable carefully and make sure you don't get it near anything like the carpet where it will get covered in dust and fabric - don't ask how I know). Some oil on a bit of kitchen roll is enough to lubricate the innards. You should be able to turn it easily by hand as it is re-inserted. When it reaches the connection to the gearbox/overdrive, that end of the cable should then slot in and prevent you being able to turn it further. You should also aim to get the cable to run in a smooth arc alongside the gearbox and up through the engine bay, through the grommet hole nearest the back of the speedo and then into the speedo. I have seen cables routed in many twisted pathways and all this does is create friction points. If the cable gets hot because of friction then the plastic bush will heat up and expand (coefficient of expansion of plastic is quite high). This will cause it to jam. Hope this helps. Keith Quote Link to post Share on other sites
Mk2 Chopper Posted April 30, 2019 Author Report Share Posted April 30, 2019 Thanks for the info Keith, when I pulled the cable out there was lubrication a little further down, but I agree the plastic part could do with some. I had no problem re inserting the cable back down the outer housing, so I think your explanation of how it moved makes sense, I foundthe knurled part wasn't even finger tight so that may have caused it to jam against the plastic part. Cheers Gareth Quote Link to post Share on other sites
Mike C Posted April 30, 2019 Report Share Posted April 30, 2019 I'd leave the oil off the last 200mm or so of cable behind the speedo. I have a tacho that's a factory repair job because of excess lubricant . Quote Link to post Share on other sites
Mk2 Chopper Posted April 30, 2019 Author Report Share Posted April 30, 2019 Thanks that's how it is now, I think the plastic jammed cause of the loose knurled nut. Gareth Quote Link to post Share on other sites
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