Trying to fix three annoying leaks (oil temp probe & speedo angle drive) | FerrariChat
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Trying to fix three annoying leaks (oil temp probe & speedo angle drive)

Discussion in '365 GT4 2+2/400/412' started by raemin, Oct 5, 2025.

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  1. raemin

    raemin Formula 3

    Jan 16, 2007
    2,397
    Lyon (FR)
    Full Name:
    R. Emin
    #1 raemin, Oct 5, 2025
    I just came across three annoying leaks on the car.

    1) The brand new oil temperature probe we installed during the rebuild is apparently leaking. Cannot say of this is the washer of it the oil leaks through the probe, but how would you address such an issue.

    2) the speedo angle drive is even more leaky which is quite unfortunate given how difficult it is to source one. Oil seems to leak through the swivel nut, but as with all oil leaks, one never knows for sure. Do you have any hint on how to service these?

    3) The last one is the vacuum modulator of the gearbox. Seems like the oil is leaking all round the round "capsule". I replaced the gearbox but did nit service it, so cannot say if the modulators is somehow sealed against the case.

    Any help greatly appreciated!
     
  2. 360modena2003

    360modena2003 Formula 3

    Jul 11, 2009
    2,469
    #2 360modena2003, Oct 5, 2025
    1) I had a similar issue - you need to drain the oil and the add a small amount of Febi silicon to the thread and a felt washer. If you continue to see oil, then it is from the body of the sensor and needs to be replaced.

    2) No experience

    3) They are cheap to replace, buy a new one.
     
  3. Theruse

    Theruse Karting

    Jan 17, 2014
    196
    Maryland
    Full Name:
    Prescott Russo
    #3 Theruse, Oct 11, 2025 at 7:49 PM
    Have had the same problem on the right angle speedo drive. If you drop the pan, the gear can be taken out from the inside. There is an O-ring on the inside and on the outside a much smaller O-ring. On my right angle drive the end cap was leaking and we resealed it, but still have some leaking. but not as prevalent as before. If someone knows another solution would be glad to know.
     

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