Joined: Feb 2018 Posts: 38 Threads: 11
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Location: Canterbury, Kent
Car type: 1936 Two Seater (Opal?)
Having just completed the overhaul of my 4 speed (3 synchro) gearbox I find that the thread on the end of the 3rd motion shaft for the drive shaft flange is damaged, the nut is also damaged but I think the shaft thread will clean up with the correct die.
Can somebody please tell me what this thread is so that I can obtain the correct die, it looks to be 5/8" x 16 tpi which suggests it could be whitform but I would welcome confirmation of this. I'll also be looking for a replacement nut but I haven't found one listed on any of the usual suppliers parts lists, could anybody point me in the right direction??
Many thanks, ..... Phil.
Joined: Aug 2017 Posts: 858 Threads: 47
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Location: North Wiltshire
Car type: 1927 Chummy, 1926 Top Hat 1938 Big Seven 1/2 a Trials Chummy
09-02-2019, 11:20 AM
(This post was last modified: 09-02-2019, 11:22 AM by Parazine.)
5/8 x 16 tpi, Sir Herbert's little ba***rd thread. Same as the crankshaft and half shaft.
Someone suggested that it was some redundant tooling Austin bought up, someone else claimed a connection with railways I seem to remember.
Tooling available from Tracy Tools in Devon.
Sorry, just to make it clear, I measured it and it is 5/8 x 16 tpi!
Joined: Aug 2017 Posts: 3,215 Threads: 100
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Location: Darkest Bedfordshire
09-02-2019, 11:25 AM
(This post was last modified: 09-02-2019, 11:35 AM by Chris KC.)
Hello Phil,
I just ducked out to the lock-up to check, forgive me if I mis-type as my fingers are now frozen!
Yes, it 5/8" x 16 tpi.
David Cochrane lists 5/8 x 16tpi taps and dies, I think it may be the same thread as a half-shaft nut.
A die is one option, or a thread chaser is sometimes handy for tidying up minor damage on larger threads.
I'm afraid I don't have a spare nut to hand or I'd post it to you.
But if you get stuck p.m. me, I might have a rusty old one in my used nuts and bolts bucket.
p.s. If I'd known Parazine was looking too I'd have stayed in the warm! But yes I also measured it.
Joined: Feb 2018 Posts: 38 Threads: 11
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Location: Canterbury, Kent
Car type: 1936 Two Seater (Opal?)
Many thanks to you both for braving the elements in order to confirm the thread size, I hope the frostbite doesn't have any lasting consequences.
I'll probably give David Cochrane a ring to make sure the dies he has are correct for the job and if all else fails I could buy the tap as well and make a new nut, quite an expensive exercise though for something I may only do once.
Regards to both, .... Phil.
Joined: Aug 2017 Posts: 444 Threads: 13
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Location: Dunchurch, Warwickshire
Phil - give me a call next week and leave a message - I will ring you back. I'm out quite a bit next week so apologies in advance if it takes me a day or so before I do.
