Harness chassis bolt problem

[delmatt]

I was hoping someone may be able to advise/help me on this one.

I tried to change the Harness in my Caterham today and have really screwed it up. The bolt that secures the outer lap belt to the chassis sheared off when I tried to remove it. I then proceeded to drill the remains of the old bolt out and have failed dismally. Without taking the inner side panes off it looks like the socket on the chassis has been drill through as well, consequently it looks like there is no way of putting a new bolt in as there is only half the socket left.

Has anybody else experienced of done this and would it be possible to weld a new one in subject to removing the side trim....about a million rivets etc. I would get someone professional to weld this of course. Any suggestions?

Thanks in advance.

[Honda Rush]

O Dear, To do a correct repair I would think you will need to drill out the rivits at the rear of the inside panel at least up to the seat front crossmember to peel it away to get at it. And possible cut a smallish hole from the outside large enough to cut away the damaged boss. Then if its an Arch chassis braze another boss in or caged chassis stick weld it in. Then ally weld a plate on the out side to close it up.Then reduce the welds and spray the repair.

[delmatt]

Yes thanks I thought that would be the case. Removal of much more than I would like etc....should have left the old harness in I reckon....apart form the fact it was so old it kept slipping loose.

I have already taken off the inner panel and can now see what I am up against. I will probably need to undo and pull the outer skin away so it doesn't heat up etc...Hopefully will get away without any paint work I think.

Thanks again. Although a magic solution would have been much better.

[Honda Rush]

Can you see where the outer skin is welded if you cut down this with a correct sheet ally blade in an angle grinder (MIND THE CHASSIS)You can then have it welded in the correct place.
Is there any chance of finding the centre of the boss from the outside then drilling a centre and going up in 1mm drill sizes and see what happens.
The boss is a full 20mm wide so even if a few threads are damaged there will still be plenty off bite to be secure.

[freebee]

Yes but would you trust your personal safety or that of others based on the bolt engagement of a "few"threads I wouldn't.

[fergus]

freebee said:

Yes but would you trust your personal safety or that of others based on the bolt engagement of a "few"threads I wouldn't.

the bolt is entirely in shear, not in tension, so the "few threads" argument isn't as dramatic as a situation where a tensile load is applied.

[freebee]

I hear what you say and I dont want to be pedantic but if its that safe why was it not designed with only a few threads of engagement.

[delmatt]

I have arranged for the nice people at Arch to look at it for me in a week or so time. They should know best and will keep me as safe as it was originally designed. Thanks for the help anyway.

[Honda Rush]

Best try the other seat belt bolts before you take it to Bruce in case more than one to do

[delmatt]

The others are really easy...been there already! I am actually going to replace both Harness now to celebrate.

The one I was going to put in is Blue and would clash with the Green and Yellow..So now the question is black or red?

Cheers.

[TeflonTurd]

I'd wait. You might be respraying the car :-0

[delmatt]

TeflonTurd said:

I'd wait. You might be respraying the car :-0

Thanks cheered me up no end!!!!

[mickrick]

If anyone can sort it Arch can. You've done the right thing by taking it to them IMO.
It'll all work out in the end.

[delmatt]

That's better much more reassuring...thank you. I will report back after next week when I take it over to them.

Assuming I don't leave it there for a reskin etc...then I would have to buy another for the summer...oh no.

[delmatt]

mickrick said:

If anyone can sort it Arch can. You've done the right thing by taking it to them IMO.
It'll all work out in the end.

It did thanks...they did a great job while I waited and no damage.. bloody long drive there and back though...I am becoming a right sissy boy in my old age.

[Zagster]

Good to hear, what did they do in the end?

[delmatt]

They were able to grind out the old socket and the half of the bolt that was left. Then clean up the surrounding area and bronze weld a new one in with a small triangular strengthening plate. Looks mighty fine and all without burning the paint or melting the ally skin right next to it.

The inside panels were then neatly riveted back into place and there is now no evidence that anyone was ever in there at all! I am as you would expect very relieved and happy...and feel much safer with the new 3 inch wide Sabelt Harness as well.

[mickrick]

[delmatt]

What should I break next then?

[mickrick]

Sit back and break open a can