Bolt or sets?

[Harry]

Afternoon all, I've not done much on the car today despite four hours in the garage, I fitted the alternator to the engine, then I started to fit my new clutch slave cylinder but could not find a bolt or set to fit it to the gear box ( Does anyone know what they are ?? ) I even removed the gearbox from the engine to check the threads as there was paint on the outer area of the holes, I think they might be 7/16 unc ?? The thread is not UNF or Metric ( I thought they may have been tapped out as metric m 10 ) Anyway once I had the box off I thought I'd check the thrust bearing again (It was a bit tight in it's fitting) and I filed a bit more off the fork sides, it's nice and free now. I then refitted the box, but I'm short of three bolts to attach it to the engine 3/8 UNF I believe. I must admit I've got a tad hacked off due to running out of UNF set screws and bolts, so many were damaged and I could not / would not use them again, it's really held me up with this job, I was tempted to convert much of it to metric but I like the idea of keeping the original fasteners.
So once the mechanical jobs came to an end I went back to rubbing down, just the bonnet left to do now.

[stevejgreen]

Re: Bolt or sets?

My guess is that if they are bolts going into a casting, they are UNC. I remember though that on a Marina Bell Housing, certainly the ones I have unbolted, had different length bolts around the bell, though I cannot remember which or why.
Pretty close to me when in the UK is Namrick or the Nut & Bolt Store. I have used them both commercially and privately.
I have never caught them out yet apart from some M12 Metric Fine socket screws, that they ordered and I had them in two days.

[Tony Stott]

Re: Bolt or sets?

namrick as well, and delivery to france at a very reasonable rate

[Harry]

Re: Bolt or sets?

Thank's Steve, after much poking about and reading etc, I have found out that the MGBs were a bit of a jumble fixings wise, the Chrome bumper type used UNF and UNC, but also a few metric Set screws and Bolts, where as the later rubber bumper type used only UNF and UNC, so after a bit more measuring I'm sure the Bolt's ( To attach the slave cylinder to the gear box ) are 3/8 x 1" 3/4 UNC. It's easy to mistake UNC for Metric, I think the thread pitch is very close if not the same but the diameter is different, and UNEF and Metric fine are very close too. The bolt's from the Marina box are too short anyway, but I've kept them. Well, I'm off to rub down my bonnet !!

[stevejgreen]

Re: Bolt or sets?

Rubber Bumper MGB would have been produced primarily for American Market and their crash safety rules. Not surprised that they stuck to Unified National threads as the Yanks don't understand Metric.

[djj_engineer]

Re: Bolt or sets?

sometimes threads used on Aluminium are the old Whitworth type. These are very coarse and have quite a deep thread.
However I have a box full of 3/8", 7/16" and 1/42 UNF bolts, setscrews and nuts.
Give me a call
Derek

[Harry]

Re: Bolt or sets?

Thanks, I have sent for a few of each from "good old Ebay" Funny enough I came across a few Whitworth bolts today. Still got my black "Snail " brand black spanners ! I been scraping a few layers of Hammerite from the screen surround, I just love it !