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Threaded bar to mount diff
David_17 - 15/5/11 at 05:47 PM

If I use M12 threaded bar with a nyloc on each end to mount my diff, will the IVA man not be happy?

The bolts i've got aren't quite long enough to get a nyloc on.

Hope someone can help.

Cheers

Dave

matt_gsxr - 15/5/11 at 05:58 PM

My SVA man didn't mind me doing this. I mounted my engine in the same way.

David_17 - 15/5/11 at 05:59 PM

Great stuff.

Wasn't sure if he'd need to see a tensile strength mark (which it doesn't have).

matt_gsxr - 15/5/11 at 06:19 PM

Many 7 style cars don't even use the rear mount on the diff.

The IVA/SVA man/woman could make statements on whether the thing is structurally sound, and fail you on that.

They don't seem to worry about it and nor do I.

r1_pete - 15/5/11 at 06:22 PM

Personally I'd get some longer 8.8 bolts, the twisting forces on the diff could be too much for threaded bar, which is not much more than mild steel.
The engine as above is rubber mounted and couldn't transmit the force needed through the rubber to sheer the bar.

David_17 - 15/5/11 at 06:37 PM

I tried to get hold of some longer ones, but apparently they're special order.

I see what you mean about the twisting forces though.

The other option is use the bolts ive got with normal nuts and thread lock.

coozer - 15/5/11 at 06:39 PM

I used 12.1 threaded bar on mine..

David_17 - 15/5/11 at 07:23 PM

Think i'll use threaded bar and if it gets questioned, have the bolts and thread lock ready and change on the day if neccessary.

indykid - 15/5/11 at 07:42 PM

Calculate what forces the studs will see and from that, determine what material properties you require.

I imagine M12 threaded rod will be just fine, even if it is only mild steel

mrwibble - 15/5/11 at 08:46 PM

surely its possible to have threaded bar made from varying tensile strengths...

matt_gsxr - 15/5/11 at 09:39 PM

quote:
Originally posted by mrwibble
surely its possible to have threaded bar made from varying tensile strengths...


loads, just googled it. Good point.


I'm still not worried about my threaded rod. The mounting bolts for the prop-shaft are M8 (in 12.8) and are much, much closer to the axis of the prop. M12 has masses more steel than double the steel compared to M8 and the forces at the fixing are much lower.


My original point was that my SVA man didn't object, and I still wouldn't expect your IVA person to.


Now you have thought about it you might as well go with high tensile, at this point there is no real disadvantage.

Just my thoughts though,

Matt