Speedo modification / rebuild

Discussion in 'Modified Shizzle' started by stirlingmoz, Nov 19, 2018.

  1. So I’ve got myself a winter project I can fiddle with in the warm and dry.

    A speedo upgrade / rebuild.

    My crewcab came with a KPH speedo

    [​IMG]

    I have just recently bought a MPH speedo face from another forum member (thanks Mark). My original plan was just to swap the faces over and not worry about the odometer reading.

    Then I scored this KPH trip speedo off eBay for a bargainous £60

    [​IMG]

    The KPH face is a bit dented, the speedo needle is broken off, the trip reset knob is in 2 pieces and the nylon gear has a split (3 o’clock position in photo below) but it all seems to work.

    [​IMG]

    So now the plan is to keep the original KPH speedo as part of the history and fit the MPH speedo gears (and needle) from this

    [​IMG]

    I’ve made a start and drilled the MPH speedo face for the trip reset button. The trip button has been superglued together and is now in one piece.

    [​IMG]

    I need to work out :

    1. How to reset the odometer reading to match the reading of the original speedo.

    2. How to cut the extra holes in the MPH speedo face so I can actually read the trip info.

    I’m currently thinking Dremel ?

    It seems that trip speedo’s particularly in MPH are quite hard to find so while this won’t be original, it will at least do the job.

    Any speedo gurus on here ?

    Stirlingmoz
     
    Last edited: Nov 19, 2018
  2. When I reset mine I disconnected the drive cog and flicked the numbers round.
     
  3. You have to remove the long pin to clock it
     
  4. The long pin with the multiple small cogs or the long pin with the numerals on ?

    Stirlingmoz
     
  5. I can`t remember I`d need to see a pic
     
  6. You can remove the long pin with the cogs on and then spin the numbers around how you wish.

    I wouldnt cut the holes with a dremel - it wont be an accurate enough job (i.e. rounded corners etc) - and as you stare at it every time you drive you'll get very annoyed by it. I would suggest taking it along to a company who can do CNC cutting and seeing what they would charge for a saturday afternoon job on it?

    ...or do as I have and just leave it as KPH, I like the "on-the-fly" maths of working out how fast I'm going :)
     
  7. Thanks for the reply. I will google local cnc engineering companies and see what’s out there.

    I hear what you say about Dremel accuracy.

    I was going to bolt the two speedo faces together (back to back) to act as a guide and finish off with a small file.

    Stirlingmoz
     
  8. You could probably get someone to do a vinyl to stick over the kph, just trip the square holes out of it then
     
  9. You mean this one with the grey cogs ?

    [​IMG]

    Stirlingmoz
     
  10. Another good idea.

    Given the number of imports I’m surprised that someone isn’t already doing that.

    There’s plenty of printers round here but I’m gonna keep that as plan ‘B’ for the moment.

    Stirlingmoz
     
  11. So pulled that pin and got the little gears out.

    The odo numerals then spin freely

    [​IMG]

    Got the speedo needle off but sadly it’s looks different to it’s late bay equivalent -

    Also got the MPH worm drive gear out

    [​IMG]

    Sadly the MPH odo drive looks brass and it’s not budging.
    Wonder why the later drive gears were nylon - a bit of cost cutting by VDO ?

    [​IMG]

    Getting it back together and getting all the numerals to line up neatly is proving challenging at the moment.
    Just got to find a method.

    Stirlingmoz
     
    Last edited: Mar 26, 2019
    Rez likes this.
  12. Have you marked the 'drag cup' position before you pulled the needle off?
    Tony
     
  13. So at the end of a fiddly few hours we have this..

    KPH drive gears replaced with MPH. Sadly the old speedo had to die as I was forced to cut the shaft with the brass gear. Once free it was easy to tap the shaft out. Put the whole thing in the vice and nervously pressed it onto this one using some 1/4” drive sockets as spacers. I considered a nylon gear but these are notorious for cracking so it seemed a logical solution.

    [​IMG]

    And I managed to reset the odometer to the correct mileage.

    [​IMG]

    To finish it off I need to source a late bay speedo needle (different id to the late bay) and cut the holes for the trip display

    Stirlingmoz
     
    Last edited: Nov 24, 2018
  14. Luckily I did. I marked the cup with a sharpie and took a photo (2nd picture) of where the needle was in its ‘resting’ position.

    Stirlingmoz
     
  15. Well done that man!
    I figured out how to do it, (which is obvious), offered to show my resto man what to do, but they were 'experts', didn't listen to me, now I have a speedo that over reads 7 mph.:mad:
    Tony
     
  16. They are the same as T25 speedos.
     
    paradox likes this.
  17. Hi, guess you missed this one
    eBay item number:
    143036811887 you'll have to search under sold listings
     

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