I need to get a set for re-doing the IRS (for cleaning holes, bolts and nuts if required) and don't want to get a big set that doesn't work with the nuts and bolts used. I seem to remember some weird english thread types.

What type of set should I get. Is SAE good enough?

 

Almost everything is SAE fine thread. The only Whitworth thread is the upper timing chain adjuster nut on the engine. If something goes into aluminium it will be SAE coarse, like some of the manifold studs into the head, but into steel or iron will be fine thread.

 

[QUOTE=muttony;2612040]I some weird english thread types.

Weird English threads? Offence taken - send this man to re-education camp to learn respect for ancient thread types!

 

I know the threads as UNF and UNC (Unified National Fine, and UN Coarse). Some electrical stuff from Lucas will also use BA, (British Association) for the smaller stuff.
Have a read: -
https://en.wikipedia.org/wiki/Unified_Thread_Standard

Edited
United should read Unified

 

On older Jaguars, the SU carbs and Dunlop brakes are also all BA fasteners.

 

The differential to rear cage and the inner fulcrum dog bone fasteners are UNC. I think you will not need a tap and die set to clean those threads, just a good spray with brake cleaner, maybe some rust dissolver if needed, followed by running the bolts in and out a few times will do it.

 

One can make a tread chaser. A crude tap. Use the bolt that fits. cut a groove perpindicular to the threads. Grind a chmfer on the front. run it in and out a few times with a light oil as alubricant. If you are fussy, use a vcumn on te opening afdter the chase.

Carl

 

First mention I've heard of this in a very Loooong time, Carl.
On the farm when I was a wee lass, tools of this sort (taps, dies and thread chasers) had a habit of crawling off. My dad's brother (the Real mechanic of the outfit) used to do this quite a lot, make impromptu thread chasers, on the bench grinder.

As you say, it worked like a charm for bolt holes full of dirt, chaff and light rust.
(';')

 

You want thread chasers for cleaning, NOT taps. You want to remove rust, dirt, etc. If you have a stretched thread situation, taps will cut excessive metal out, and then you might strip a nut or bolt with proper torque.