SlotForum banner rear wheel grub screws too tight

2767 Views 34 Replies 21 Participants Last post by  Martyn_
I've just bought a new Audi R8C (CA12C) which has had its rear wheel grub screws over-tightened in the factory. I've ruined three new allen keys trying to loosen the screws, only have two undamaged allen keys left and don't want to ruin those. I need to loosen the grub screws to reposition the rear wheels, which have been fixed too far inboard at manufacture.

I've tried alternately gently heating and cooling the axle and wheel assembly, which succeeded in loosening one screw, but the other is still jammed tight. Any ideas how to undo it?
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I managed to get one stuck slot.It grubscrew out by getting a small self tapping cap screw, putting a dab of superglue on the tip and screwing it in as hard as I could to the grubscrew. This was after I had tried everything I could think of, I was gob smacked when it worked. Since then I have redrilled and tapped all my wheels and gears to the same size as NSR
Chris A, I can assure you I have experienced this problem with a Slot.It grub screw on my Lola and don't appreciate being called a wind up merchant. I have been racing on and off for nearly 50 years and haven't experienced this problem with the larger size grub screws. I have snapped a hardened wrench to get one out but it came out and I just ground the wrench down.
Maurizio, I can't believe that at the revs most hard body cars use a larger grub screw can make much difference. With a larger grub screw you remove more material from the wheel, I realise that there is a weight difference between the wheel and grub screw material but it must be extremely small. At the position it is being near to the axle it can't make any difference. In BRSCA 1/32nd sports strap motors they are pulling over 150,000 rpm and they use the larger grub screws in gears. The latest thing for the really fast guys now is to balance gears and wheels and tyres, this is mainly due to in consistency in manufacturing though
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