Mondial 3.2 trans noise | FerrariChat

Mondial 3.2 trans noise

Discussion in 'Mondial' started by Cadillacbart, Dec 17, 2016.

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  1. Cadillacbart

    Cadillacbart Formula Junior

    Nov 26, 2013
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    Denver, CO
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    John
    #1 Cadillacbart, Dec 17, 2016
    I have this posted in the tech forum for a few days. Posting here as well as I've had no luck finding anyone over there that recognized the condition. I'm probably not doing a great job of describing what I'm hearing.

    1988 Mondial 3.2

    In October, I replaced the shift shaft seals (Verell's version- terrific!) and pan gaskets, and obviously replaced the motor oil and gear oil at the same time. I used Mobil1 75W-90 synthetic gear oil, which may have been a mistake as I am now reading it's not great for the metals in my trans. That's probably a different thread.

    The job went well, all has been leak free and shifting well in the past 150-200 miles since the change. Only one thing that I have noticed "different" in a negative way. Cruising in 4th gear, off throttle, there's a noticeable "ringing noise" that sounds like its coming from the shifter itself, but I'm sure its just transference from the gearbox as there's no rotating parts under the shift tunnel. That's what it sounds like though- almost as if you held a screwdriver lightly to a rotating driveshaft. That's the best way I can think of to describe it. When on the gas in gear, the sound goes away. No issues in any other gear, car shifts well through all gears.
    Other notes:
    I did replace the silent blocks in the shift shaft too (also Verell's).
    I did have to adjust the shift forks slightly upon reassembly.
    I did have to adjust the shaft at the turnbuckle slightly upon reassembly.

    Overall the project went really well. I hate to have to open it up again, unless there's something going on here that's causing damage.

    Sorry for the long post, just trying to provide context. Perhaps someone has seen this symptom before?

    Thanks,

    John
     
  2. Russ Gould

    Russ Gould Formula 3

    Nov 8, 2004
    1,073
    #2 Russ Gould, Dec 17, 2016
    Look for a socket resting between chassis and driveshaft.
     
  3. BOKelley

    BOKelley Formula 3
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    #3 BOKelley, Dec 17, 2016
    I will preface by stating that I haven't yet made any adjustments to the tranny in my 3.2 so I am unfamiliar with the procedure. However, one thing you point out is that you had to adjust shift forks and shaft turnbuckle which gets me to thinking that you might have adjusted some slack out of the system...perhaps too much. So let me ask...when in 4th and off throttle, have you tried putting slight pressure on the shift lever (in all directions) to see if the noise goes away?

    Brock
     
  4. Cadillacbart

    Cadillacbart Formula Junior

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    #4 Cadillacbart, Dec 17, 2016
    Thanks Russ,
    I'll check that out.
     
  5. Cadillacbart

    Cadillacbart Formula Junior

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    #5 Cadillacbart, Dec 17, 2016
    Thanks Brock,

    I feel like I may have done that, but there's very little/ no play in the shifter now, so that's a really good thought. Could be an adjustment is necessary.
    As you are aware, it's 4 degrees in Denver today, but as soon as I have a chance to get back out to test this, I will.
     
  6. mike32

    mike32 F1 Veteran

    May 13, 2016
    5,835
    Isle of man- uk
    #6 mike32, Dec 17, 2016
    If i am reading this correctly you rejointed the gearbox sump joint ? I take it you got the spacers back in the correct holes when you refitted it. I cannot remember what they do but worth asking.
     
  7. BOKelley

    BOKelley Formula 3
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    #7 BOKelley, Dec 17, 2016
    Yep, tis a bit chilly, made it to 1 deg here today. The only engine i had running was on the snowblower!
     
  8. Cadillacbart

    Cadillacbart Formula Junior

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    #8 Cadillacbart, Dec 17, 2016
    Thanks Mike. Yes I accounted for the spacers balls and springs back there.
     
  9. Wade

    Wade Three Time F1 World Champ
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    #9 Wade, Dec 17, 2016
  10. Cadillacbart

    Cadillacbart Formula Junior

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    #10 Cadillacbart, Dec 17, 2016
    Hi Wade,

    Yes, that's the Mobil1 gear oil that's in thee now.

    The thread is really helpful. Based on what I read there, I'll likely do a change to Redline.
     
  11. mike32

    mike32 F1 Veteran

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    #11 mike32, Dec 18, 2016
    I took mine off not knowing about them and they all dropped on the floor, anyone know the purpose ?
     
  12. BOKelley

    BOKelley Formula 3
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    #12 BOKelley, Dec 18, 2016
    I changed mine out to Redline as well. A bit easier shifting from 1st to 2nd when cold so it does help but won't completely eliminate the problem...there are other threads that have what seems to be a logical explanation to the problem and a viable cure that involve drilling pressure relief holes. The fact that the Redline is a lower weight oil explains why it is effective in reducing the problem and it isn't a big enough issue for me now to start playing dentist.

    I did wonder whether or not my box might become noisier by using a lower wt. oil but that didn't happen for me. That is why I reasoned that some of the adjustments you made are now causing the noise you hear...ie, maybe there is now pressure on a fork that causes rotational friction and noise that wasn't there prior.

    Brock
     
  13. Cadillacbart

    Cadillacbart Formula Junior

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    #13 Cadillacbart, Dec 28, 2016
    Done.
    Mobil1 out. Redline in. 4 70W-90NS + 1 70w-90.

    Hoping I feel difference when I take it out for a drive tomorrow. At any rate, good to have the Mobil1 out of there.
     
  14. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #14 Rifledriver, Dec 29, 2016
    Last edited: Dec 29, 2016
    Not a big difference between the Mobile 1 and the Redline.

    If you side loaded one of the forks or mis adjusted the selectors it could make the noise you speak of.
     
  15. Cadillacbart

    Cadillacbart Formula Junior

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    #15 Cadillacbart, Dec 29, 2016
    So I got to drive the car about 50 miles today. I did notice that if I move the shifter forward while in fourth gear the sound will subside. So I will need to figure out what adjustment I can make to adjust the throw ever so slightly forward. It feels like only a couple of mm at the shifter will do it. Skipping fourth gear for now to avoid wearing anything.
     
  16. BOKelley

    BOKelley Formula 3
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    #16 BOKelley, Dec 30, 2016
    Good deal...sounds like you are zeroing in on the cause, unfortunately my sense of what is needed resides in the gearbox and not in the shifter as adjusting the shifter seems to be treating the symptom and not the cause. Perhaps it is in an adjustment that affected the positioning of the 4th gear shaft. In my view, adjusting the shifter would reposition all of the gear settings.

    Food for thought...I could be wrong.

    Brock
     
  17. Rifledriver

    Rifledriver Three Time F1 World Champ

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    #17 Rifledriver, Dec 30, 2016
    I agree. Nothing good will come of it if there is an internal adjustment causing this noise and it is not fixed properly.
     
  18. blownfuse

    blownfuse Karting

    Jul 16, 2012
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    Campbell, California
    #18 blownfuse, Jan 5, 2017
    They're spring loaded detents, used to hold the transmission in gear. Here's your study guide: Shift Linkage and Shift Rails
     

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