Colin Lindsay Posted September 21, 2021 Report Share Posted September 21, 2021 I've been given a Spitfire FK gearbox (US-spec 1300?) with J-type overdrive and am intending an overdrive conversion into the Herald 13/60 but am missing parts from around the speedo drive. I have an angle drive already, I know there's a bracket and a bolt missing but what does the bracket hold in place? I can't find a good diagram and my Workshop Manual only covers D-type. Link to comment Share on other sites More sharing options...
johny Posted September 21, 2021 Report Share Posted September 21, 2021 Have a look at the Canley or Rimmers diagrams Colin. The clamp plate holds a threaded boss for the cable to connect to.... Link to comment Share on other sites More sharing options...
DanMi Posted September 21, 2021 Report Share Posted September 21, 2021 A J type overdrive is a J type overdrive so look under spitfire 1500 https://www.canleyclassics.com/?catalogue=triumph-spitfire-mkiv/1500&diagram=triumph-spitfire-mkiv/1500-j-type-overdrive-unit-rear-case-speedo-gears-and-flange. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 21, 2021 Author Report Share Posted September 21, 2021 Canley's website is amazingly slow tonight; gave up after nearly ten minutes of waiting for the page to load, and checked their home page, too - no go. I'll check that tomorrow. Knowing my luck the required parts will be NLA and made from unobtanium. Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 21, 2021 Report Share Posted September 21, 2021 https://www.overdrive-repairs.co.uk/buy-spares.php?cat=J Type Spare Parts List ferule and clamp £8.50 Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 21, 2021 Author Report Share Posted September 21, 2021 Thanks Pete, good to know they're so cheap and more importantly available. I'll dismantle the entire speedo drive to see if anything else is required. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 22, 2021 Author Report Share Posted September 22, 2021 23 hours ago, Pete Lewis said: https://www.overdrive-repairs.co.uk/buy-spares.php?cat=J Type Spare Parts List Pete - any idea if the speedo drives need to be swapped over? I think mine is damaged at the end, so may as well replace it. It's an 18 tooth so from a US-spec Spitfire box. Were the gauges similarly adjusted for the US market, so if I fit a US drive with a cable to a UK speedo will it affect the accuracy? Would the drive gear on the output shaft need to be changed too, as any other number of teeth might not mesh? Here are the available options: Link to comment Share on other sites More sharing options...
DanMi Posted September 22, 2021 Report Share Posted September 22, 2021 18 tooth matches canleys for the mk4 Jtype. I believe on the 3 rail boxes it was the speedo head tpm that varied but on the single rail the drive varied and the speedo was always 1000tpm. The 3 rail j type is rare. Link to comment Share on other sites More sharing options...
Peter Truman Posted September 23, 2021 Report Share Posted September 23, 2021 For what it is worth an analysis I did a while ago trying to determine what speedo drive (No of teeth) to fit with Spit 1500 single rail internals into a 3 rail box with J type O/D with a std 4:11 diff. Oops how do I upload a Microsoft Excel spreadsheet? Link to comment Share on other sites More sharing options...
Clive Posted September 23, 2021 Report Share Posted September 23, 2021 5 hours ago, Peter Truman said: For what it is worth an analysis I did a while ago trying to determine what speedo drive (No of teeth) to fit with Spit 1500 single rail internals into a 3 rail box with J type O/D with a std 4:11 diff. Oops how do I upload a Microsoft Excel spreadsheet? Take a screenshot, pop that into "Paint" then post that as an image? Not everybody has MS office.... Link to comment Share on other sites More sharing options...
NonMember Posted September 23, 2021 Report Share Posted September 23, 2021 1 minute ago, clive said: Take a screenshot, pop that into "Paint" then post that as an image? Not everybody has MS office.... Better to print/export as PDF - it's then smaller (file size) and scalable. It may even be searchable, if you're really lucky. Link to comment Share on other sites More sharing options...
Peter Truman Posted September 23, 2021 Report Share Posted September 23, 2021 Not having a good day inserted the tables into the Spotted section so I've deleted it and will start again, Bu**er! Please let me know if there's any errors, & I must revisit and work out the best speedo gear for a Spit 1500 engine and single rail 1500 gearbox gears (fitted into a 3 rail case) with a J Type Overdrive mated into a Spit Mk2 with a std 4:11 diff, and speedo head. Peter T Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 23, 2021 Author Report Share Posted September 23, 2021 That hurt my neck, turning my head sideways so I just turned the monitor sideways and hurt my arms instead, before deciding that it was easier to just rotate the image. Interesting to note that if my box is FK, so Spitfire Mkiv for the US market, it has a blue 18 tooth drive; the one listed below appears to be blue 24 tooth? The 18s are all brown? Link to comment Share on other sites More sharing options...
DanMi Posted September 23, 2021 Report Share Posted September 23, 2021 I would phone overdrive repairs and have a chat, they were very friendly when I phoned in the past and should have all of the details but as the 3 rail J type was short lived they won't have the details listed on the website Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 23, 2021 Report Share Posted September 23, 2021 at least its easy to swap pinons you can calc the TPM if the car is mobile mark road and tyre , stick a card pointer on the speedo cable or its drive push car exactly 52.8ft count the needle turns divide 5280 by the turns and thats the TPM you are trying to match if the car is not mobile you need to dived 52.8ft by the rolling circumference of the tyre then turn the wheels exactly that amount which might be easier than pushing the car !!! sorry i only work in ft and ins. Pete 1 Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 24, 2021 Author Report Share Posted September 24, 2021 I've gone ahead and ordered the same as the original; I'll see how it performs once fitted and adjust as necessary. I'm just happy that the parts are available! Link to comment Share on other sites More sharing options...
Colin Lindsay Posted September 29, 2021 Author Report Share Posted September 29, 2021 Overdrive Spares of Sheffield have delivered the missing parts; very nice they are too. A few gaskets and seals and that gearbox will be ready to fit later in the year. 1 Link to comment Share on other sites More sharing options...
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