Hi All,

As many know i have made a special transmission box. Because i work in the stainless industri, i bolted the complete thing together with grade A2-70 Bolts.

Now after fitment etc. i was wondering if it is needed to swap them with 8.8 grade ones. Would be a real real pitty because i just have installed everything back onto the car! the tensible strenght wouldnīt be a problem and they arenīt alone
(the part is hold together by 6 M6 A2 bolts...

What will Mr SVA say? The bolts arenīt gonna fail. Go ing to cry if i need to swap them...

Tks

are the bolts going to be visible to Mr SVA? are they even going to be checked by Mr SVA?

I dont recall SVA man taking any interest in the gearbox bolts. If you are in the industry im sure you have enough savvy to use what you are happy with. I personally wouldnt worry about it.

Guess they will be visible..

will take some pics about the situ!!

Anyway first i will test the hole setup and testdrive it...

Then i will invest more time in changeing the bolts. problem is like always..

Room the bolts are long and i gues i cant change the most critcial ones.

What a chit those f*** hurries!!

A2 = 450N/mm2 (yield strenght)
8.8=650N/mm2 (yield strenght)

it means that A2 = 44% weaker.
(Yield strneght is the point where the bolt keeps his "new" lenght.

What a mess...

Tks

p.d. on the other side 6 times M6 surface x 450Newton

= allot of newton

BOLT LINK


[Edited on 21/12/06 by tks]

I seem to remember that they need to be 8.8 or better. I'll try to remember where I saw it.

I'd change them.

Just found it. Grade 8.8 bolts or better ARE required for seat belt anchorages or other structural areas.

No specific requirements for any other bolts that I can see.

You could argue that suspension/hubs etc are structural - and I'm sure if the SVA man raises it then thatll be his arguement.

Page 3 of seat belt and anchorages section of 6th ammendment March 2004 SVA manual

its just the box sides and bearing rings wich are bolted with that.

The box itself is with M8x8.8 bolted tot the chasis.

Tks

No requirements for graded bolts with the exception of seatbelt mounts.
ie You can build it with anything you like and unless the test man was VERY cocerned that there was a major design flaw or weakness you're OK as they won't even look.

Seatbelt bolts and wishbone bolts were the only ones my SVA man checked,and to be honest i'm sure he only checked the one on the wishbones to see how much or if enough thread had passed through the nyloc which is understandable.

don't understand whayt you've done but in worst case scenario, what would happen if the bolts snapped?

will the parts still reamin in place or drop onto the road?

I'm certain you won't have an SVA problem with the stainless bolts where you have used them. It's little different to e.g. someone using stainless bolts between the engine and bellhousing, and there are certainly no SVA requirements for them.