News

F430 - rear main seal leak ?

Discussion in 'Technical Q&A' started by PaulCr, Oct 5, 2020.

  1. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    F430 F1 2008 23kkm - noticed oil pool under car early this year and finally got around to investigating at the weekend. Removed bottom tray (a lot of oil) and obvious leak is at junction of main crankcase and clutch housing. Cleaned it up - returned few hours later to see oil drips collecting again on the engine block under side. Almost certain its the main crankshaft seal, but why does it continually drip if the engine is off for several days - is there a gravity feed of the oil to the main bearing ? Other possibilities ? ......and yes, my fault for leaving the car too static for months on end. Cheers, Paul
     
  2. To remove this ad click here.

  3. windsock

    windsock Formula Junior
    Rossa Subscribed

    Nov 29, 2006
    536
    Arlington, Washington
    This is really common. The clutch dust eats the rear main seal over time. As the car is a dry sump system they will not leak while running because the oil in the engine is minimum and it is being pumped to the sump in the gearbox. Once you turn the engine off the oil will eventually equalize between the engine and the sump. This puts the rear main under the level of the oil and they leak. Easy fix is to replace the rear main seal and inspect the clutch components while your in there.
     
  4. Ferrari Tech

    Ferrari Tech Formula Junior

    Mar 5, 2010
    639
    Georgia
    Full Name:
    Wade Williams
    If you put a rear main seal in, it is not an option to reseal the throw out bearing. It has to be done. Once you slide the gear box back, the throw out bearing then extends to the end of stroke. The clutch diaphram fingers have been holding it, so now it slides onto all of the clutch dust that is on the flange. It will leak if not addressed. I always allow my customer to have the option of replacing the clutch and ALL associated components. No need going in again for something you actually have apart now.
     
    2NA and JL350 like this.
  5. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,521
    San Carlos, CA
    Full Name:
    Mitchell Le
    This is not an "easy" job.

    Excellent point.
     
    2NA likes this.
  6. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    Thanks guys, really solid explanation and advice. So until I get it repaired I should park on a hill to keep the oil in the gearbox - just joking. I heard that the leak is also assocaited with lack of use - but the abrasive dust seems to be the main killer - yes ? Out of interest, the flow of oil back into the engine crank case with the engine off, what route does the oil flow take - via the pumps or are there other oil channels ? Cheers, Paul
     
  7. To remove this ad click here.

  8. Ferrari Tech

    Ferrari Tech Formula Junior

    Mar 5, 2010
    639
    Georgia
    Full Name:
    Wade Williams
    The oil is from the oil pan, not the trans, so park facing downhill. ;)
    The oil gravitates from the tank (clutch housing) into the oil pan through the oil pump.

    I am a big believer in driving these cars. I tell clients all the time that just starting and moving it around won't do it. I also remind them that everything in the car should be turned on or off or adjusted and messed with. Every knob, button, switch, lever, handle, or whatever. Move it, or adjust it. Keep it all working The Italian tune up is a real thing. I have left HUGE black clouds of crap behind cars on test drives that just never get run hard. The rev limiter is there for a reason, you should know where it is and what it feels like. The oil temp need to get fully up as well to steam off the moisture in the engine. I have come back from test drives with the oil fully hot and just let the engine run with the cap off the tank and watch the steam roll out just to help get the moisture out. You won't get it all but try anyway.
    Sorry for running off a bit, rant over.
     
    JL350 and unreelviper like this.
  9. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    Thanks Merlin - yes, and the smile gets bigger as the engine starts to scream. Concerning the leaking oil seal, what's your view - simple ageing, becoming too dry when parked up, dust from the clutch, other? - ever heard of cases where the seal recovers once the car get used regularly.....well I have to ask.
     
  10. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,521
    San Carlos, CA
    Full Name:
    Mitchell Le
    Never heard of that one, but ... one can always reach for the stars. Not!
     
  11. Manda racing

    Manda racing Formula 3
    Silver Subscribed

    Feb 25, 2015
    1,118
    Bakersfield, Ca
    Full Name:
    Mark
    You could mess up the clutch if it gets oil on it. Right?
     
  12. To remove this ad click here.

  13. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    Yes, tis reaching for the stars but was a half serious question. I work with vacuum system - needs very good tightness with elastomer seals - but all the seals are static. A leaking vacuum seal can sometimes be recovered by adding silicon oil or grease. So if a dynamic seal like the main bearing becomes dry, then perhaps the presence of oil could reset - eg by driving out contaminants at the sealing line due to the positive pressure in the crankcase or simply softening the seal. If the seal is damaged due to cracking/scoring then its impossible to regain tightness.
     
  14. Ferrari Tech

    Ferrari Tech Formula Junior

    Mar 5, 2010
    639
    Georgia
    Full Name:
    Wade Williams
    I am not sure there is a definitive answer as to why. Clutch dust doesn't really go inward behind the flywheel, I think not running is more likely or it just doesn't want to do its job. As for getting better, I don't think it will get better. Then again, it isn't really hurting anything except making a mess. Again, the oil comes from beck of the flywheel and doesn't get on the clutch so no harm there. Drive it until you can't stand it and then get it fixed.
     
    2NA likes this.
  15. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    Thanks MerlinTech. I'm at ~ 50% clutch wear so would be good to get a bit more life out of it before doing the big job. I'll keep you updated if any miracles happen. Cheers, Paul
     
    Ferrari Tech likes this.
  16. PaulCr

    PaulCr Rookie

    Jan 15, 2018
    6
    Geneva, Switzerland
    Full Name:
    Paul Cruikshank
    Update: sent car to R&D Automotive in Manchester, UK - privately owned Ferrari repair specialists (ex-Ferrari mechanics - ask for Nick). They inspected clutch and flywheel - neither required replacement (just the release bearing), so total was ~2000 GBP - great job, would highly recommend.
     
    Ferrari Tech likes this.

Share This Page