PST Carbon Fibre Tailshaft Failure

Discussion in 'Technical' started by rob260, Oct 4, 2010.

  1. rob260

    rob260 Administrator Staff Member

    Yeah I will keep everyone posted!

    I will also email the vendor whom I purchased it from but we are not the best of friends so not expecting much joy there either.......
     
  2. rob260

    rob260 Administrator Staff Member

    I emailed Mark@pstds.com on Monday and just now sent an email via the "contact us" form on their website.

    Is there another email that you know of?

    I hit up street to strip aka street to track whom I bought the shaft from but he said couple of years ago and out of warranty. I'm not actually sure what the warranty is on these and can't find anything on the website? Either way couple of years yes but the shaft would not have done 5000kms so not an acceptable lifespan in my opinion...
     
  3. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    thats the right email.

    Yeah problem with warranty when building a car is by the time you fit it on warranty is over :(..1year from memory ..
    I bought mine directly from PST.
     
  4. beaver

    beaver southern zeds

    The only

    thing thats lighter now is your pocket rob, CFTS= expensive rubbish.
     
  5. mungyz

    mungyz Well-Known Member

    Sticking screws/rivets/bolts/pins etc through carbon fibre will just create high stress points & create a failure point.

    Correct design & correct manufacturing process's will prevent the shafts from failing - have a hunt around & see how many 350Zs have had shafts fail.

    Your neighbour needs to do a little more research on composites, he's a little off the mark.
     
  6. Boost Junkie

    Boost Junkie Member

    isn't this the second CF shaft thats failed on this forum?
     
  7. rob260

    rob260 Administrator Staff Member

    Update

    OK so a little update for interested parties...

    After the local distributor who sold me the shaft was decidedly unhelpful I did manage to get in contact with Mark Veldhuis at PST who offered to repair and test if I returned the shaft.

    I have to say despite the frustrating circumstances of the initial failure PST have been very good about the whole thing. They repaired the shaft, replaced the yoke and flange that I butchered to use with my current steel shaft, rebalanced and torqued up the shaft to check for slippage. I don't know what torque it was tested to but they do shafts for bigger motors than mine so I can only assume torque specs are sufficient.

    I paid for freight both ways and the cost for components that needed replacing. PST covered the cost of labour and repairing the original fault. I thought that was pretty fair.

    They did mention that the shaft should be kept away from heat at all times, so I will be looking at heat shields etc before I think about refitting it. I don't know how practical this will be given the design of a Z32 -probably goes some way to explaining why c/f shafts work well in OEM applications but can be something of a compromise when used as an upgrade.

    Will keep you all posted
     
  8. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    hey Rob

    thats good that they fixed it ..

    I still think your issue with heat is due to your dumps /exhaust running in the trans tunnel which makes it very close to the yoke on the c/f shaft .

    I'll see how mine holds up ... even though my exhaust will be further away I may still look at putting an alloy shield where the yoke/unis are
     
  9. Martin Williams

    Martin Williams Well-Known Member

    I have a CFTS in my track car and its been good so far. I had stock turbos and aftermarket dumps. I am at this time fitted an upgraded engine turbos and CES will be making the dumps, I will ensure that they design them well away from the TS. This thread has been very useful to me. Thanks all
     
  10. rob260

    rob260 Administrator Staff Member

    Bit more of an update for anyone interested....

    Yesterday Andrew at ASR modded and extended the factory heat shield to help insulate the shaft more against heat. Excuse the iphone pics...

    [​IMG]

    [​IMG]

    All in all it's a very simple setup but surprisingly time consuming! The factory shield has had some fibre based heat mat riveted to it, and has been extended using some ACL dimpled heat shield which has been secured to the gearbox mount. The fibre heat mat is all one pice, and Andrew has used riv nuts to secure it to the ACL shield. We left the overhang at the back to further prevent any heatsoak into the transmission tunnel, should keep the floor a little cooler.

    We thought about trying to make up a one piece longer heat shield with the ACL stuff but it wasn't quite wide enough and no time to order a big sheet. Also there is very limited room and we wanted to leave plenty of clearance between the mat/shielding and the tailshaft.

    Hopefully this will do the job, the outcome is that the tailshaft is now doubly insulated from the rear of the gearbox mount back.
     
  11. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    Looks good

    .
     
  12. tassuperkart

    tassuperkart Its a lie I tell you!

    It seems to me that the best thing about a CF driveshaft is that WHEN it fails, by all accounts the damage is less extensive.....

    Meh, woftam in my view (along with ally shafts for road cars). Good for impressing tyre kickers tho if thats important.
    Just me tho.
    L8r
    E
     
  13. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    I have it mainly for the weight savings .12.5lbs
    less rotational and overall weight ..2 birds 1 stone.
    Safety is a bonus .
     
  14. rob260

    rob260 Administrator Staff Member

    Broken Again

    So for anyone interested the tailshaft failed again yesterday, under very similar circumstances to the original failure.

    Had been driving the car around for most of the day, lots traffic and a warm Sydney afternoon (37* ambient). It seems that the heat has once again affected the bond at the yoke (keeping in mind alloy yoke/carbon shaft so it's bonded rather than welded) and it has slipped big time turning onto the F3 to drive home. Managed to roll the car into the shoulder and wait two hours for the tow truck.

    Ironically but the time I got the car home some two and a half hours later the bond seemed to have "set" enough to move the car around in the driveway (presumably re-sets as it cools down) but I wouldn't be driving it any further than that.

    Long story short I'm not sure if I'll bother sending it to PST for another repair. If I did it would only be to put the thing on eBay. I will be putting a chrome molly shaft back in mine when I have some time off in three weeks or so.

    Anyone considering a carbon shaft YOU HAVE BEEN WARNED. Same failure twice (albeit over a two year period) in near identical circumstances with a product from the market leader, even with the additional heat shielding pictured earlier in the thread...
     
  15. Nigel300

    Nigel300 New Member

    What a waste of time and money. Try Jeff Lagerway tailshafts on 97584015.
     
  16. badxtc

    badxtc kirby's bitch

    ddddaaaaammmmmm man , , yeah ill be going moly aswell , but will you be going for a single or 2 piece , im accualy thinking of going moly 2 piece now , with the center bearing on place , with the power our cars make it really plays on my mind , i have a single on there now , and im just waiting for it to bust up ,

    p.s and you know what is it really worth it , i dont think so just piss it of and start again me think as i will be ,


     
  17. rob260

    rob260 Administrator Staff Member

    Cheers Nigel -JP has a guy that makes 'molly shafts for them. Not sure who it is but quality seems very high so I'll be happy to run with one of those. Appreciate the suggestion though :)
     
  18. rob260

    rob260 Administrator Staff Member

    Why are you thinking two piece Alex? Single piece molly shaft should be very strong. Interested to hear your train of thought though :)
     
  19. Nigel300

    Nigel300 New Member

    Hasn't Graham-Tekky got one for sale atm?
     
  20. rob260

    rob260 Administrator Staff Member

    Thanks mate just sent him an email.

    Tell you what I regret selling the steel one I had made last time this happened...
     

Share This Page