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Anyone have an extra 308 speed sensor?

Discussion in 'Technical Q&A' started by PeterS, Jun 30, 2004.

  1. PeterS

    PeterS Three Time F1 World Champ
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    Jan 24, 2003
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    I need to pop in a speed sensor on my '77 308 to confirm that mine is in-op. Can anyone in the US help?
     
  2. magnesium

    magnesium Rookie

    Nov 15, 2003
    47
    You talking about the speedo sender on the gearbox? Very often the guilty component........ And you can check it out without a spare. Either use a waveform generator or if you don't have one, use a file and a screwdriver........ Disconnect the electrical plug onto the sender and connect 2 wires with crocodile clips onto the terminals leading to the speedo head. Connect one clip to a file and the other to an old screwdriver and with the ignition switched on, run the screwdriver very gently down the file. This will generate a (rough) sawtooth waveform that's good enough to see if the speedo works. No, it's not a factory approved method but it's free and it does work - I got the speedo up to 60mph with some practice using this method.
     
  3. PeterS

    PeterS Three Time F1 World Champ
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    Mag..Thanks..It is the sending unit. I had my speedometer checked out OK, so It can only be the sending unit. Expensive unit!
     
  4. Darolls

    Darolls F1 Veteran
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    Try Sodacom, he has the best prices I've seen.
     
  5. magnesium

    magnesium Rookie

    Nov 15, 2003
    47
    Expensive - certainly is when you see what's inside. You CAN actually repair them if you really feel like it. Very often the solder holding the components onto the circuit board cracks and you get a dry joint - all you have to do is resolder........ And sometimes water gets in there, corrodes them up and you have to clean them or even replace a component........ They're exposed to heat, vibration, splashes....... Repairing the speedo sender is another distinctly non-factory, non main-dealer procedure! Also worth bearing in mind that they are fitted to a number of other cars - lots of Fiats, some Lancias - but mostly the right-hand-drive versions only (where the awkward route for the cable might have made them unreliable!) So they put that really reliable electronic stuff in there.
     
  6. bernardo66

    bernardo66 The Crazy Cat Man
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    Dec 14, 2003
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    I've been looking for one. Sodacoms doesn't seem to have it and Ferrari UK seems to be out of stock. Any other hints??
     
  7. dm_n_stuff

    dm_n_stuff Global Moderator
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  8. Darolls

    Darolls F1 Veteran
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    Sodacom has them listed.

    Go to the Sodacom site. In the search box type in, Speedo Sensor.

    You'll see them at the bottom of the page.
     
  9. KurtK328

    KurtK328 Formula Junior

    Mar 6, 2001
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    There are two types of speedo sensors - an early and a late type.
    I believe your car is using the early type - the one you see at Sodacoms is the later type.
     
  10. Jay GT4

    Jay GT4 F1 Rookie

    Oct 16, 2001
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    I don't think it matters which one you use but don't quote me on it. I put the later one in my 308 GT4 and it works fine.
     
  11. bernardo66

    bernardo66 The Crazy Cat Man
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    Are you serious? The later one (for injected cars) doesn't seem to look at all like what I have on mine. Will it fit?

    Anybody out there ever swap these units?
     
  12. BigTex

    BigTex Seven Time F1 World Champ
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    Pinnacle Motorsports in Houston Texas had one on hand they put in to comfirm my speedo was dead..dead...dead.

    1977 308GTB
     
  13. Jay GT4

    Jay GT4 F1 Rookie

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    All I know is when I ordered the part the old number was superceeded by the new one. Ferrari UK would know better, look on the owners site.
     
  14. redhead

    redhead F1 Rookie
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  15. bernardo66

    bernardo66 The Crazy Cat Man
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    I got an e-mail from Ferrari UK. The part was out of stock, but they should be recieving some....oh yeah, and the price is now 150GBP, double of what is indicated on the owners site.
     
  16. KurtK328

    KurtK328 Formula Junior

    Mar 6, 2001
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    They cannot be swapped.
     
  17. KurtK328

    KurtK328 Formula Junior

    Mar 6, 2001
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    There is two diff numbers for the later one and the only diff. between them is the plug on the wire.
     
  18. bernardo66

    bernardo66 The Crazy Cat Man
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    First off, I want to thank DM-N-Stuff, Readhead and Darolls for your help in trying to locate a speedo-sensor. In the end, I was able to purchase one from Partsource (which is located not too far from Montreal).

    The real adventure was trying to install it. Apart from the sensor being located in an awkward place (had to remove the rear tire and wheel well), the pin that connencted the old sensor to the pinion gear was seized in the gear!!!! So...I took out the gear, tried to pry the pin out, only to have the bit that stuck out, break off. After much cursing...I took the gear to my local mechanic, who managed to dislodge the pin by heating the upper tip of the gear and immediately dunking it in water.

    I can only conclude that the engineers that designed the car....never had to work on them!!!

    Cordiali Saluti
     
  19. gerritv

    gerritv Formula 3

    Jun 18, 2001
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    Hi Bernie
    What might the part number be from Partsource? did they say what other car it was used on? I might need one for a 1976 308GT4.

    Mine might or might not be dead as well. It doesn't look like any of the ones on Sodacoms.

    Gerrit in Toronto
     
  20. bernardo66

    bernardo66 The Crazy Cat Man
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    Hey Gerrit,

    No he didn't mention if the part was the same for a 308GT4. However, looking at the parts catalogue on the owners site, it seems to be the same piece as for the carb GTS/B. As for the part at Sodacom's not looking quite like what you have, don't let it fool you. When I got my part delivered, I thought they had made a mistake and shipped me the wrong part. Upon closer inspection, only the outer casing was different and the rest of the inner and attaching mechanisms were the same. The part no. I used was 124146, but the chap at Partsouce was also able to locate it by description. Very knowledgable fellow. Good luck.
     

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