Bonnet bolt hinge size?

Post by **Oxymoron** » Tue Jul 17, 2018 3:41 pm

Hi,
I was adjusting the bonnet position today and on undoing and re-tightening one of the nuts which screw to the captive bolts in the underside of the bonnet, I found that it was just spinning around and not tightening!

The thread of the bolt and nut are both stripped. I need to re cut the thread of the bolt if possible...Anyone know what size/thread that the bolt is?...Is it metric or imperial?

Cheers,
Jez

Post by **philhoward** » Tue Jul 17, 2018 3:46 pm

7/16" (11mm) spanner? If so, I'll guess they're 1/4" UNF

Post by **Oxymoron** » Tue Jul 17, 2018 3:48 pm

Hi,
I've been using a 13mm spanner on the nuts...

Post by **Coupe Racing** » Tue Jul 17, 2018 4:40 pm

Oxymoron wrote: ↑
Tue Jul 17, 2018 3:41 pm
Hi,

The thread of the bolt and nut are both stripped. I need to re cut the thread of the bolt if possible...Anyone know what size/thread that the bolt is?...Is it metric or imperial?

Cheers,
Jez

If the thread of the bolt and nut are stripped - then re-tapping wont work - you will be left with a weak thread

Post by **philhoward** » Tue Jul 17, 2018 5:03 pm

Oxymoron wrote: ↑
Tue Jul 17, 2018 3:48 pm
Hi,
I've been using a 13mm spanner on the nuts...

In that case, likely to be 5/16"UNF.

Post by **Oxymoron** » Tue Jul 17, 2018 8:09 pm

Coupe Racing wrote: ↑
Tue Jul 17, 2018 4:40 pm
Oxymoron wrote: ↑
Tue Jul 17, 2018 3:41 pm
Hi,

The thread of the bolt and nut are both stripped. I need to re cut the thread of the bolt if possible...Anyone know what size/thread that the bolt is?...Is it metric or imperial?

Cheers,
Jez
If the thread of the bolt and nut are stripped - then re-tapping wont work - you will be left with a weak thread

The last piece of thread where it tightens looks ok...it's the rest that's mangled!
The bolt cannot be removed as it's part of the bonnet.

Post by **scimjim** » Tue Jul 17, 2018 8:11 pm

I’ve had to replace the captive studs in SE5 and SE6a bonnets before, they’re welded to a plate that’s bonded into the bonnet.

Post by **Oxymoron** » Tue Jul 17, 2018 8:49 pm

I've adjusted the bonnet slightly forwards away from the bulkhead, so that it doesn't catch at the rear.
Is there any vertical adjustment available, as my air cleaner is touching the bonnet in a couple of places.

Post by **scimjim** » Tue Jul 17, 2018 9:50 pm

Is one of the hinge holes slotted on the 6a?

Post by **Oxymoron** » Wed Jul 18, 2018 8:56 am

scimjim wrote: ↑
Tue Jul 17, 2018 9:50 pm
Is one of the hinge holes slotted on the 6a?

Yes the hinges are slotted thanks, but the slots were obscured by earthing straps!
The bolts weren't particularly tight, so the bonnet has probably sunk down at the rear....now adjusted!

Post by **scimjim** » Wed Jul 18, 2018 9:35 am

Excellent

Post by **Oxymoron** » Thu Jul 19, 2018 1:48 pm

Well I've recut the thread on the stud using a die and tightened it up with a new nut!...Phew!
One job always seems to create another on the Scimitar!