Rockape Posted September 9 Report Share Posted September 9 Greetings… if you have seen my recent TSSC Facebook posts, you will know that my speedo seized up. This resulted in the nylon drive pinion getting stripped and the cable tying itself into a knot. I now have all the components out of the car and have the following questions 1. I need to source a replacement drive unit (hoping/praying/wishing the drive gear in the gearbox extension is ok - I am thinking the steel gear would easily turn the nylon to mush (the car was 200 m from home when it all went pear-shaped) 2. I need to refit the drive cable which the FB community said is too long. Does anyone know the correct length. I may be able to reduce this one, or as above, find a replacement 3. the speedo needs to be refurbished or replaced 4. am thinking of beefing-up the instrument lighting with LEDs. 5. What are these terminals for on the back of the speedo? any advice/thoughts/suggestions on any of the above numbered points would be very welcome Link to comment Share on other sites More sharing options...
Gully Posted September 9 Report Share Posted September 9 Yes, I saw the post on Facebook. In terms of the speedo repair, I've used Speedy Cables (London) successfully for repair / recalibration work. They're based in Swansea, despite their name! https://www.speedycables.com/ The terminals / wiring on the back of the Speedo with the green cables - that's your voltage stabiliser for the feeds to the temperature and fuel gauges. LED instrument lights are a popular upgrade - they come in various colours, so you can replicate green etc. if the coloured insert into the gauge is missing. There are a few threads on here if you search LED lighting. I seem to recall the Club Shop sells the right bulbs, but not something I've done myself. Not sure on the replacement drive unit - my first port of call for most things is Canley Classics, as their parts diagrams are a great way of finding the right part numbers. I then tend to check their pricing against James Paddock. They should be able to confirm the correct length speedo cable too. Gully 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 9 Report Share Posted September 9 canley list the pinion but 119131 worm is N/A these are mostly plastic so may have suffered same as your pinion https://www.canleyclassics.com/?catalogue=triumph-spitfire-mkiii&diagram=triumph-spitfire-mkiii-gearbox-mainshaft Pete Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 That is all good info - thanks. what are your thoughts on the cable length issue? It seems relatively trivial to me - and the longer it is, the softwr the bends can be? Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 10 minutes ago, Pete Lewis said: canley list the pinion but 119131 worm is N/A these are mostly plastic so may have suffered same as your pinion https://www.canleyclassics.com/?catalogue=triumph-spitfire-mkiii&diagram=triumph-spitfire-mkiii-gearbox-mainshaft Pete That’s not good at all ! Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 You might be able to inspect the output shaft gear through t'hole - one of those camera thingys would be useful here. You dont want to put a new drive in and have that damaged as well☹️ I changed the oil, high beam and indicator repeater for LED with good effect. However didnt do back lights as I thought they would be too much for night driving so just repainted the white insides of the instrument cases and it works well. You have to be careful with light creep as the internal rubber shields disintegrate and then light from one bulb can make another look like its illuminated... Link to comment Share on other sites More sharing options...
trigolf Posted September 9 Report Share Posted September 9 1 hour ago, Rockape said: am thinking of beefing-up the instrument lighting with LEDs. I bought LEDS for the instrument lighting from Classic Car LEDS - see advert on back page of latest Courier mag. The difference in llumination levels was like night and day - no pun intended! Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 That is all good info - thanks. what are your thoughts on the cable length issue? It seems relatively trivial to me - and the longer it is, the softwr the bends can be? Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 Dumb question. How do you get the pinion out of the housing. I don’t see any circlips or similar holding it in🤔 Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 well yes to a certain extent but if too long you can have the opposite problem of where to lose the excess! Eh the drive is held in by that bolt showing in your previous photo... Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 oh I see what you mean now😁 Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 All in the free to download workshop manual Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 1 hour ago, johny said: well yes to a certain extent but if too long you can have the opposite problem of where to lose the excess! Eh the drive is held in by that bolt showing in your previous photo... 1 hour ago, johny said: You might be able to inspect the output shaft gear through t'hole - one of those camera thingys would be useful here. You dont want to put a new drive in and have that damaged as well☹️ I changed the oil, high beam and indicator repeater for LED with good effect. However didnt do back lights as I thought they would be too much for night driving so just repainted the white insides of the instrument cases and it works well. You have to be careful with light creep as the internal rubber shields disintegrate and then light from one bulb can make another look like its illuminated... Interesting comment from Classic Car LEDs…do not change the Ignition warning lamp as this could drain the battery over a long run - they recommend leaving the ignition warning lamp as an incandescent… Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 1 hour ago, johny said: All in the free to download workshop manual Yes - this all makes sense - but no indication how the pinion is held….nuat push fit? Link to comment Share on other sites More sharing options...
Pete Lewis Posted September 9 Report Share Posted September 9 (edited) the pinion is a free fit the only resistance is its small oil seal so give it a pull it may be seized and you need both parts to make a runner a finger in the drive port will give you a clue if the worm is fine these re generally plastic and can suffer a chew up . for RHD Mk3 its common with other models but non overdrive is GSD111 with any speedo cable if the inner is a bit short or too long you can with some car screw the outer spiral wound sheath to make small inner /outer ,dimensional adjustments Pete Edited September 9 by Pete Lewis Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 3 minutes ago, Rockape said: Yes - this all makes sense - but no indication how the pinion is held….nuat push fit? Yes just push it out and inspect/change the end oil seal. Think youre more likely though to find a complete unit secondhand... Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 6 minutes ago, Pete Lewis said: the pinion is a free fit the only resistance is its small oil seal so give it a pull it may be seized and you need both parts to make a runner a finger in the drive port will give you a clue if the worm is fine these re generally plastic and can suffer a chew up . for RHD Mk3 its common with other models but non overdrive is GSD111 with any speedo cable if the inner is a bit short or too long you can with some car screw the outer spiral wound sheath to make small inner /outer ,dimensional adjustments Pete Seems incredible the worm would be plastic inside the gear box….i really don’t fancy taking the box out to get the speedo to work ! y Link to comment Share on other sites More sharing options...
trigolf Posted September 9 Report Share Posted September 9 15 minutes ago, Rockape said: Interesting comment from Classic Car LEDs…do not change the Ignition warning lamp as this could drain the battery over a long run - they recommend leaving the ignition warning lamp as an incandescent… Correct. An LED bulb fitted to the ignition warning lamp holder, does not draw enough current, compared to a tungsten bulb and so the charging regulation does not regulate the charge to the battery correctly. Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 35 minutes ago, Pete Lewis said: the pinion is a free fit the only resistance is its small oil seal so give it a pull it may be seized and you need both parts to make a runner a finger in the drive port will give you a clue if the worm is fine these re generally plastic and can suffer a chew up . for RHD Mk3 its common with other models but non overdrive is GSD111 with any speedo cable if the inner is a bit short or too long you can with some car screw the outer spiral wound sheath to make small inner /outer ,dimensional adjustments Pete Just ordered an endoscope to fit onto the phone….relatively inexpensive nit of kit that will be useful Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 53 minutes ago, Rockape said: Seems incredible the worm would be plastic inside the gear box….i really don’t fancy taking the box out to get the speedo to work ! To make you feel a bit better if necessary it should be possible to do it without removing the box as you remove the gearbox cover, jack the rear up so that the flange and gearbox rear casing can be removed, then tap the drive gear along and off the end of the mainshaft.... Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 53 minutes ago, trigolf said: Correct. An LED bulb fitted to the ignition warning lamp holder, does not draw enough current, compared to a tungsten bulb and so the charging regulation does not regulate the charge to the battery correctly. Also sometimes a filament bulb will just start to glow which a useful indicator of an emerging problem with the charging system - presumably a LED wouldnt do this... Link to comment Share on other sites More sharing options...
PeteH Posted September 9 Report Share Posted September 9 Theoretically, would a resistor in parallel with an LED provide the right conditions? Pete. Link to comment Share on other sites More sharing options...
johny Posted September 9 Report Share Posted September 9 Certainly cant get a LED to glow as its either on or off... Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 16 minutes ago, johny said: To make you feel a bit better if necessary it should be possible to do it without removing the box as you remove the gearbox cover, jack the rear up so that the flange and gearbox rear casing can be removed, then tap the drive gear along and off the end of the mainshaft.... Link to comment Share on other sites More sharing options...
Rockape Posted September 9 Author Report Share Posted September 9 Thanks ….when I look at the diagram in Moss am damned If I can locate the drive gear on any of the shafts…probably looking at the wrong gearbox. This is 4speed, no synchro on first unit - no overdrive Link to comment Share on other sites More sharing options...
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