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Sheared hub shaft, check the photo!

Discussion in '308/328' started by Corsa308, Aug 3, 2009.

  1. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
    Full Name:
    Steve D
    #1 Corsa308, Aug 3, 2009
    Last edited by a moderator: Sep 7, 2017
    So there I was, just after a full days practice and into qualifying. Only a couple of laps down, out of a 2nd gear corner and pedal to the metal and the engine spins up as if it has come out of gear. But it was more than that, no drive at all. I make the "lap of shame" behind the tow truck and thinking it was a broken drop gear ordered the tilt tray and took the car home. At least the engine seemed AOK.
    Drained the transfer case expecting a nice pile of metal bits, but no, all clean.
    Checked the gear selector, the clutch operation, all good. Damn, don't tell me it's the gearbox!
    I had the LHS rear wheel off and the inner fender to get access to the transfer case, I just happen to turn the LHS brake disk and noticed that the CV joints weren't turning at all. Strange I thought, don't these guys usually always turn together?
    So now I have it pretty much pinpointed, drive going into the back of the hub, no drive coming out the other side.
    It was either a stripped spline or sheared shaft.
    This was an area I hadn't been before. As would happen about the only area on the car I hadn't worked on or replaced any components.
    I won't bore you with the trouble I had getting the disk off, but it would'nt so I pulled the whole hub off the car, including the disk and got stuck into it on the bench.
    Yes I got the disk off and with a bit of gentle hammer work got the shaft out and this is what came out.
    Bloody amazing really. You can see that the fatigue has been going on for quite a while (dark coloured metal) and had got down to only about a third of the shaft being connected (bright metal).
    Obviously the energy of fullpower in 2nd gear was the last straw and it failed completely.
    Lucky in many aspects as I was only going about 60 or 70 kmh at the time. 20 secs before that it was 180kmh.
    Lucky in that it was a RH turn and hence keeping the weight onto the LHS and keeping the wheel pushed in towards the car.
    Lucky that the shaft was pretty hard to get out and hence wanted to stay with the bearing.
    Lucky in that I was just lucky.

    So I know people have discussed this before, but here is just another example of a hub shaft failure.
    No damage at all to my car accept for the failed component. Even the bearings are AOK. Again, bloody lucky.
    So what am I going to do now you ask! Well of course I may as well get stuck in and replace those wheel bearings while I am there.
    Even though the bearings are pretty much sealed, the separate oil/dust seals are knackered so they need replacing.
    And of course I now think about the other shaft and with body and wellbeing in mind I will do the RHS rear as well.
    I could either get the shaft tested, or I reckon I will just replace both with nice new hub shafts.
    Yes it will cost, but.

    So, I do have the part number, and I have sent out a few e-mails to the usual suspects about availability.
    Does anyone know if anyone has ever attempted to make new versions of these shafts?
    I am looking down the barrel of maybe $1200 a piece for replacements. Surely you could them made new for that price, and maybe you could get them made stronger with shot peening etc.
    Any suggestions welcome.
    I know you could get 2nd hand ones, but you don't know what they have gone through and really you would want to get them tested beforehand.

    Apart from that, and not trying to stir something up, but after 33 years, I reckon everyone should think about these somewhat vulnerable shafts and the strain they have had all these years. Looking for a project? Take yours out and get them tested and then do the bearings and seals while you are at it.
    Hopefully this won't happen to your car, but I reckon I have taken more than my share of the luck for the moment.

    I will let you know what the RHS shaft looks like when I take it out next weekend.

    Steve
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  3. enjoythemusic

    enjoythemusic F1 World Champ

    Apr 20, 2002
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    Steve,

    Ahh yes, the lap of shame at the track... :(

    No one i know makes alternatives and do not believe there is a drop in replacement (from Porsche, BMW, etc), though nowadays a guy with a scanner and appropriate fabrication machines should easily be able to reverse engineer them and make them out of better materials. Look at volume discount and sell them to others, as i have a feeling in a few years you will be able to sell more and more of these. The problem you had is normal, especially for guys who actually drive their Ferrari 308s at the track. It has been speculated (not proven) that it is the bolts that loosen, which then causes fatigue/problems. Frankly, virtually nothing in a car designed for lightness/racing/exotic cars under stress will last forever.

    PS: Am glad you finally got the brake rotor off and agree, while you are in there you may as well.... Welcome to racing :)

    PPS: what matters is that YOU are ok. Keep the rubber side down and have fun at the track :)
     
  4. mustardfj40

    mustardfj40 Formula 3

    Jun 17, 2004
    1,135
    Northen California
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    Ken
    My other hobby is off-road rock crawling and I often to see these axle studs breaks on the trails and I usually carry my own spare axles. To reduce the chance of breaking these axles, I swapped them out for chromoly axles which are much stronger than stock, there are couple places that make custom axles that you can contact. The shops will ask you to send in your shaft and give an estimate for cost and delivery, Here are some of them:

    http://www.moserengineering.com/Pages/Shop-Services/shopservices.html

    http://www.dutchmanms.com/4_axles.html

    Here's my favorite, he makes one of _the_ best axles for Toyota 4x4s, I am running these in my truck. You can try to contact him to see if he would custom make your shafts:

    http://www.longfieldsuperaxles.com/

    Btw, if you already broke one chances are you will break the other one, I would do both axles.
     
  5. pad

    pad Formula 3

    Sep 30, 2004
    1,409
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    Paul Delatush
    There is probably more demand that you think. I know I've been concerned about breaking the shafts, especially since I run slicks on the track. Please keep us posted.
     
  6. Newman

    Newman F1 World Champ
    Professional Ferrari Technician Consultant Owner

    Dec 26, 2001
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    Newman
    I would not run a 30 year old 308 on a track without new stub axles, seen this before! Show us pics of the car too!
     
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  8. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
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    Steve D
    #6 Corsa308, Aug 3, 2009
    Last edited by a moderator: Sep 7, 2017
  9. Newman

    Newman F1 World Champ
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    Newman
    Very nice, so when the wheel went off into the rhubarb and the suspension hit the road it didnt do any damage? Usually the rear lower quarter extension takes a hit from the wheel.
     
  10. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
    Full Name:
    Steve D
    Ken thanks for that.
    I know the car will be off the road for a while anyway so I am keen to see what the story is about getting new ones made.
    I will send these places an enquiry and see what they reckon.
    If we can get a newer, tougher shaft made so we don't have to worry about it agian, then that is a good thing.

    Steve
     
  11. Nuvolari

    Nuvolari F1 Veteran
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    Sep 3, 2002
    5,651
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    Rob C.
    Stub axle failures on 308's are common when tracking with rubber that produces more lateral grip than anything available when the car was new. This essentially means that all modern tires and especially R compound tires will place too much load through stub axles causing them to fail. This is not a design flaw but rather technology has overcome the 'safety' that was built into the original design. While older axles are more prone to failure the difference in track miles is minimal between an old and a new axle. That said, 308's that are being tracked should have the stub axles replaced regularily as part of preventative maintenance. Without a large re-design of the mounting there is not enough room to beef up the axles enough to withstand the load. I say run off a few axles and replace them every 10 track days or so. With an unbroken car this is a simple procedure and addresses one of the only weak points on the 308 when being tracked.
     
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  13. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
    Full Name:
    Steve D
    No nothing came off as such, thats why I reckon i was so lucky.
    Just lost drive and had to get towed back to the pit garage with everything intact.
    The break was between the two bearings and not at the flange, so the flange and it's remaining stub were still in the bearing in the hub.
    So even though it wouldn't of stayed in there forever it kept everything in place.
    Replacing the other shaft might seem a bit of overkill, but there could've been so much damage (cost) if the wheel did come off I may as well replace both shafts and sleep better at night. Or at least the night before the next meeting!

    BTW, how is that fabulous car of yours going? Is it finished?

    Steve
     
  14. f308jack

    f308jack F1 Rookie

    Jun 7, 2007
    4,267
    Cape Town, South Afr
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    Jack Verschuur
    You did what I have thought about many times: install the 208 Turbo ducts in the rear fenders. Looks very nice!

    Sorry to be off topic.
     
  15. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
    Full Name:
    Steve D
    Absolutely agree. I run Dunlop SD01's. They are fabulous tyres and you can get them in three different compounds. I also ran them on my Alfa 105 Targa car.
    Very sticky tyres.
    The ones on the black car are just about knackered but have lasted very well, and I have to say that the car looks after the rears very well indeed.
    I will probably go to the newer version of that Dunlop tyre very soon.

    Steve
     
  16. Corsa308

    Corsa308 Formula Junior

    Apr 22, 2007
    281
    Sydney, Australia
    Full Name:
    Steve D
     
  17. Newman

    Newman F1 World Champ
    Professional Ferrari Technician Consultant Owner

    Dec 26, 2001
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    Newman
    Wow you're lucky, I probably should have read your entire first post too lol. My 308 is finally done, what a relief. Ive been to one FCA meet with it this year and been too busy to do any more. The car is a blast to drive. When I saw your side ducts it reminded me of my boxer ducts, didnt think of the 208Turbo but that makes more sense. Shouldnt cost too much to have some super strong ones made, make some extras and sell them so your two are free.
     
  18. luckydynes

    luckydynes F1 Rookie

    Jan 25, 2004
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    pit bull
    Frank Capo/Modena Engineering in Australia told me he'd made 'em and would make up some more back when I was exploring this. He's made everything for these cars.

    I'm running "later generation" used models that I had sonic checked and get magnafluxed whenver I have things apart back there.

    If I don't want to make something for my 308's I just call Frank :). Check with him. I have his contact info if it's not on here somewhere.


    cheers
     
  19. luckydynes

    luckydynes F1 Rookie

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    If someone is really passionate there's a much better design that can be incorporated.
     
  20. luckydynes

    luckydynes F1 Rookie

    Jan 25, 2004
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    http://www.youtube.com/watch?v=C9dNg-dAEBw&feature=channel

    Hossier R6 :)

    I think it's time for another tear down ... I got a track day coming up :)
     
  21. Aircon

    Aircon Eight Time F1 World Champ

    Jun 23, 2003
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    caused by accident damage maybe? the hard hit of a curb perhaps?
     
  22. enjoythemusic

    enjoythemusic F1 World Champ

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    Nice driving and WOW those Hoosiers on the 308 give nice stick! Would love to see a G circle, looks like just over 1G of grip.
     
  23. davehelms

    davehelms F1 Rookie

    Jan 3, 2004
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    Dave Helms
    Good write up Steve.

    Those with the 2v small diameter shafts need to look very closely at this.
     
  24. Nuvolari

    Nuvolari F1 Veteran
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    Sep 3, 2002
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    Rob C.
    The OP was very lucky to have it break where it did causing only a loss of drive. I know someone who had the same type of failure and only first noticed it when his rear wheel overtook him on the track. He continued to notice it as he hit the guardrail though.
     
  25. luckydynes

    luckydynes F1 Rookie

    Jan 25, 2004
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    Thanks Steven especially coming from you sir :)!

    Definitely over 1G 'cause I was seeing that with worn street tires on the street.

    How many hours of track time did you put on your car between inspections?

    Cheers,

    Sean
     
  26. enjoythemusic

    enjoythemusic F1 World Champ

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    {Blushing}


    Looks like maybe 1.1G or so, but hard to tell for sure. MUCH better grip than the Mich PS2 (wet/damp) or the Pilot CUps is the dry.


    Define inspection. ALWAYS gave her a good look over (after each run) and bolt check (each day) plus various fluid changes (each event). Was fortunate to have a few engineers/mechanics who KNEW the car and about tracking Fcars and what to look for. Trust me, no one here really wants to know the costs involved INCLUDING myself. The new owner was given a VERY thick book of ALL service records rom the day this Euro-spec car reached US shores and SPECIFICALLY told to NEVER add it up my 'donations' and tell me the costs. Seriously, i DO NOT ever want to know though let it be said the car was well-prepped and parts re-engineered or replaced for non-Ferrari better bits.

    PS: the car passed inspection at an event yet afterwards i found a near fatal flaw while doing my own checks (a cracked coolant hose). Was 20 minutes to my run group and fixed her and lost only 5 minutes of the 20 minute run group. Had she let go on the track, the mess would have been highly dangerous to others on track as am sure i'd see the flaggers and thus caused no engine damage due to said coolant loss (was the small hose on the upper part of engine/driver's side). So sometimes even after inspection it is ALWAYS good to trust... but verify.
     
  27. luckydynes

    luckydynes F1 Rookie

    Jan 25, 2004
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  28. enjoythemusic

    enjoythemusic F1 World Champ

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    The PO did A LOT to the car. The shafts were checked and i did replace the boots and had it all inspected by a guy who KNOWS these cars. On a side note, he used aero-grade grease/lubbricant and not ordinary automobile stuff.

    Maybe i was lucky at not cracking a shaft as she was a Euro 1985? Still, great guy Aussie racer Steve really could make a nice go at it selling better shafts as these cars are getting long in the tooth. Better anti-sways are also nice as the 308 really rolls with stock bits.
     

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