Crunchy 3->2 downshift | FerrariChat
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Crunchy 3->2 downshift

Discussion in '308/328' started by flyngti, Feb 22, 2010.

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  1. flyngti

    flyngti Formula 3

    Jul 16, 2009
    1,245
    Snohomish, WA
    Full Name:
    Eric L
    #1 flyngti, Feb 22, 2010
    After years of storage by a previous owner and months of work by me, I finally had a chance to drive my car on the road today. It was after work and I didn't go far, but I immediately noticed two Bad Things. One is that my clutch is slipping. It's not noticeable starting from a stop, but it's really pronounced when going up a hill. I can give it gas and watch the rpms go up without a corresponding acceleration of the car. The other thing, which is more alarming, is the fact that I can't seem to do a 3->2 downshift without crunching the gears. I've read all about the 2nd gear that doesn't like shift when cold, but I don't think this is my problem. I can shift up through all the gears smoothly. The only problem seems to be in the 3->2 shift on the way down.

    Any ideas here? I'll probably need to replace the clutch (unless an adjustment fixes the slipping) but what about the downshift? Am I looking at a rebuild?
     
  2. rizzo308

    rizzo308 F1 Rookie
    Silver Subscribed

    Sep 12, 2004
    2,776
    Perth, Australia
    Full Name:
    riggio
    #2 rizzo308, Feb 23, 2010
    i go the clutch, but worst case you may have to replace 2-3rd syncro.
     
  3. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
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    Sam
    #3 sammyb, Feb 23, 2010
    The 3-2 transition is a notoriously bad one. It will be very crunchy when cold, but better when warm.

    First things first -- address the slipping clutch. If it doesn't engage/disengage properly, you're going to crunch.

    Try adjusting the clutch (which is what I'm in the process of doing) and see if that fixes both problems. If you can fix the slipping without the crunch, you can always double clutch. (Shift from 3rd into neutral, let out the clutch, blip the throttle, then clutch in and put into second.) If you can double clutch, you don't need synchros. ;)
     
  4. Red 328 GTS

    Red 328 GTS Formula Junior

    Aug 27, 2007
    888
    Sydney, Australia
    #4 Red 328 GTS, Feb 23, 2010
    How long ago was the gear oil changed?

    I had the same issue with my E36 M3. I changed the transmission oil to Redline and the problem disappeared.

    Search Redline and you will find heaps on it to improve shifting.
    Cheers,

    Bob.
     
  5. ferrari 512 tr

    ferrari 512 tr F1 Rookie

    Nov 16, 2008
    4,179
    Australia
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    Paolo
    #5 ferrari 512 tr, Feb 23, 2010
    is redline good brother bob?
    ill have to try it
     
  6. Red 328 GTS

    Red 328 GTS Formula Junior

    Aug 27, 2007
    888
    Sydney, Australia
    #6 Red 328 GTS, Feb 23, 2010
  7. Difaz

    Difaz Karting

    Mar 30, 2005
    114
    Sydney Australia
    Full Name:
    Phill
    #7 Difaz, Feb 23, 2010
    Definitely try replacing the oil. I use a 75w90 mineral based oil.
    I have seen 308's that will not go up gears without crunching let alone down and the problem was completely cured by replacing with correct oil. (gearbox still working perfectly 8 years later).
    It seems that many modern and/or synthetic oils produced today are too slippery, that is they reduce internal friction levels so well, that the synchros on older ferrari cars at least, will not synchronise.

    This of course will not help the slipping clutch but a slipping clutch will not make gears crunch. A dragging clutch, one that is not disengaging properly will make gears crunch however.

    Difaz
     
  8. flyngti

    flyngti Formula 3

    Jul 16, 2009
    1,245
    Snohomish, WA
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    Eric L
    #8 flyngti, Feb 23, 2010
    Thanks for all the suggestions. As part of the resurrection of this car, I changed all the fluids, including the transmission oil. Right now, it's got Redline MTL in the gearbox. I know, I've read the Great Debate about which Redline gear oil to use. I chose MTL because 1) I've had good experience with it before and 2) I happen to have some in the shop from a previous car. I'll try the Redline 75w-90NS to see if it's any better. Hopefully, adjusting the clutch will cure the slippage.
     
  9. BigTex

    BigTex Seven Time F1 World Champ
    Owner Rossa Subscribed

    Dec 6, 2002
    79,368
    Houston, Texas
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    Bubba
    #9 BigTex, Feb 23, 2010
    You can adjust a slipping clutch once, if you catch it quickly...is my experience.

    OR, it may be gone, with final wear.

    Royal Purple 75-90W here.....it's local.
     
  10. hardtop

    hardtop F1 World Champ

    Jan 31, 2002
    11,294
    Colorado
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    Dave
    #10 hardtop, Feb 23, 2010
    Good chance your 2nd gear synchro is shot but you can drive it forever if you learn to do a good double clutch with blip. Not a bad idea with 3X8s actually even with good syncros.

    Dave
     
  11. Beta Scorpion

    Beta Scorpion Formula 3

    Jun 22, 2006
    1,379
    #11 Beta Scorpion, Feb 23, 2010
    Yes, I always try to not use the synchros.
     
  12. flyngti

    flyngti Formula 3

    Jul 16, 2009
    1,245
    Snohomish, WA
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    Eric L
    #12 flyngti, Feb 23, 2010
    Ok, I think I've got a plan of attack. Since the clutch is slipping pretty badly, I'm going to go ahead and replace it. I have my doubts anyway that any amount of adjustment is going to make a difference. Even if it does, it'll be a temporary fix as this slipping clutch is going to get worse, not better. Birdman has kindly agreed to loan me his Baum ring nut tool and I just placed an order for a clutch kit.

    After the new clutch is in, I'll try a different gearbox oil to see how much of a difference that makes in my 2nd gear issue. Difference or no, I'll work on my double clutch technique for smoother shifts. If it does turn out to be a synchro issue...well, I'll deal with that down the road.
     
  13. Davvinci

    Davvinci Karting

    Dec 11, 2009
    162
    California
    Full Name:
    DavidoSpeedo
    #13 Davvinci, Feb 24, 2010
    When i first got my 308, I had read about the 2nd gear dilemma when cold. Some people had raved about Swepco 201. I have never had the problem, even cold. FWIW, I feel fortunate to have tried this first. I don't think I will ever use anything else after reading some of the threads. Just a thought.
     

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