Gearbox speedo drive connection damaged

I was installing a new speedo cable a the gearbox end and realised that the brass threaded fitting has been hit by something and the threads are distorted, just wondering if anybody has any ideas how to to remove the unit, (I am assuming the stud above the threaded brass connection holds it in place, don’t want to remove this until I am sure) and once removed how would I go about getting the threads straightened out, I am thinking heat and a die , or maybe shorten the length of the treads ?
I am assuming these fittings will not be available anywhere
Any suggestions welcome

You should be able to withdraw the brass part from the rear casing after removing the bolt 25.

Once the brass part is out you could dress it on a lathe.


If it is still circular and just has damaged threads, you might be able to restore the thread profile with a a thread dressing tool - a must in the tool box for us tragics. If you are not familiar with them, they are a type of file with a selection of eight different common thread forms for freshening up old and damaged threads - male threads only. Has got me out of trouble countless times.

These spigots are easily damaged during gearbox removal and should be removed from the box before removal. Or cap it with a rubber crutch tip.

Peter L

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Yes, remove the locking bolt and it should slide out, unless it is damaged.

Walt at Vintage Jag Works in Idaho or another Moss gearbox specialist may have one.

I have had good fortune repairing damaged threads with very small triangular files

If you are very careful, and use light and magnification you can almost always restore the correct thread profile, (or reduce it enough to not interfere), which is especially important to get the threaded parts started.

So long as most of the threads are undamaged, it will hold well enough

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Thanks all for the replies, I have ordered a thread dressing tool and will see how I go. no doubt I will have more questions this great forum members can offer advice on shortly