J Type Overdrive Housing - Thread Pitch

[Bainzy]

Does anyone know what the thread is in this hole, or have one on a bench they can test some bolts in for me?

There's a pair of these holes at the back of the overdrive unit that would be perfect for attaching a bracket to for a vehicle speed sensor. I've tried a few bolts I have lying around but nothing seemed to fit properly.

[thescrapman]

They are unc. Prob 3/8 so need a 9/16 spanner. Usually hold the remote for tge gearstick on.

[yorkshire_spam]

If I'm looking in the right place on Canleys:
http://www.canleyclassics.com/?xhtml=xhtml/diagram/spitfire1500towerendcover.html&xhtmlcatalogue=xhtml/catalogue/spitfire1500.html&category=gearbox&xsl=diagram.xsl
They would be: HU858     SETSCREW - 5/16" X 1" UNC

edit:
Actually - I dunno at all - I notice you are looking for the ones on the "underside" not the ones that support the gear stick.

[Bainzy]

6797 wrote:

Actually - I dunno at all - I notice you are looking for the ones on the "underside" not the ones that support the gear stick.

Correct - should've made that clearer in the post! I think they were probably for attaching the unit to the chassis of other cars they were used on or something?

[thescrapman]

Those holes are used if installed into a dolomite.

Cheers