Seat belt anchor thread sizes

[TheGriffalo]

Does anyone know for certain what thread the seat belt anchors are in the chassis? I think they are 7/16" unf but I can't get them off to check at the moment. I want to run a 1st tap through mine after all the chassis painting is done.

[VARLEYHYD]

Chim deffo 7/16"UNF on mine

later cars also seem same but not 100% cert

G

[CLN1]

My 98 Griff is 7/16" UNF

Colin.

[Pupp]

Just on this subject, what are they like to get out? Was looking at mine recently, one of which is a bit corroded, and I'm hoping they're not going to snap like carrots if they need to be leaned on... experiences?

[seb400]

Pupp
One of mine (V8S) was problematic when had to take the body off, end of last summer. The seat belt anchor bolts are specific (high-tensile steel?) unlikely to snap. The real issue is the alignment of the drilled holes in the bodywork to the weld-nuts on the chassis. The vertical bolts into the chassis pull the bodywork down which tensions the horizontal mounting bolts against the drilled holes through the fibre-glass. It may be easy enough to unscrew them, but getting them back in again can be a problem.

Steve

[nawarne]

seb400 said:

Pupp
One of mine (V8S) was problematic when had to take the body off, end of last summer. The seat belt anchor bolts are specific (high-tensile steel?) unlikely to snap. The real issue is the alignment of the drilled holes in the bodywork to the weld-nuts on the chassis. The vertical bolts into the chassis pull the bodywork down which tensions the horizontal mounting bolts against the drilled holes through the fibre-glass. It may be easy enough to unscrew them, but getting them back in again can be a problem.

Steve

I would agree that they are HT bolts. Having said that, I did manage to shear the head and about 1/2" of thread when I went to replace the passenger side belt. (I guess that the strength is in tension so that is why the bolt failed under 'twist'.)

Upshot was a trip to my local garage who did a drill out & re-tap for £50....which considering the job took a couple or 3 hours wasn't bad, I thought.

Nick