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Audi A3 Rear Undertray Bolts

Discussion in 'Car Repairs / Maintenance' started by Caesar, 20 Oct 2019.

  1. Caesar

    Caesar

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    Dear All

    just sheared rear undertray bolts win an Audi A3 2009 1.6 TDI Model!

    Does anybody have an idea what size they are and where I can get them from?

    I prefer the old hex Head Bolts replacement if possible? Far easier to work with and even if you round them easier to score a diagonal line in them!

    Many thanks.

    Best Regards

    Caesar
     
  2. Burnerman

    Burnerman

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    What's up, Caesar - are the torx heads rounded off, or have the bolts sheared? Usually they are 6mm and sods for sticking. Replace them with stainless hex if you can move them, but if its impossible its time to be creative with the cable ties :whistle:
    John :)
     
  3. DIYspanner

    DIYspanner

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  4. Caesar

    Caesar

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    Hi Burnerman / DIYspanner

    Apologies for not getting back to yourselves as I have been away. I had to cut the undertray around the 2 offending bolts as I could not get them off!

    I still need to get the bolts off as they have well and truly rounded them! Someone has used brute force in the past on them and they are well and truly stuck!

    Thinking of cutting a slot into them with cutting disc and then bring to unscrew them!

    Thanks both of you for all your valuable help as usual.


    Best Regards

    Caesar
     
  5. Burnerman

    Burnerman

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    Is there any chance of getting any heat around the damaged screws......i.e no plastics, pipes or whatever nearby?
    These things are always a curse, and if you think Audis are bad, try Citroen :eek:
    John :)
     
  6. DIYspanner

    DIYspanner

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    My solution was to power file the heads off and then remove the clips with hammer and chisel.

    With my old Rover 45, may it rest in peace, the fasteners screwed into the subframe and rusted in, it was drilled holes and ny-ties to fasten the cover up.

    If you do use metal screws again, give the threads a good greasing.
     
  7. Stivino

    Stivino

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    Weld another nut or bolt onto them. The heat will free it and the new nut will give you something to work with.
     
  8. Burnerman

    Burnerman

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    I think the French have the last laugh over us, concerning these.....(New Citroen Berlingo starring here)
    Rectangular slots in a hollow front subframe, inserted in the slots is a square nut with its own captive cover that sort of clips into the slot (cant remember the name of them)
    Undoing the screw causes the nut to jump clear of its clip and spin within the subframe. To make matters worse, the screw is in a deep hollow of the undertray moulding and the heads are hardly visible :eek: so they cant be ground off, and drilling only spins them :(
    Oil change sir? That'll be 3 hours labour then (n)
    John :)
     
  9. DIYspanner

    DIYspanner

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    Are these the clips John?

    [​IMG]
     
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  10. Burnerman

    Burnerman

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