Rear hub thread - damage

[Tony Press]

I am sure all of us face this issue from time to time but can't justfiy the outlay for a die when it is only going to get used rarely. Without wanting to do our cherished suppliers out of any sales, might us UK-based Friends perhaps buy a die between us and post it around to each other as needed? I'd chip in. Just an idea.

Some eight years ago I bought a then available hub thread Stock and Die to donate to the club Spares board where various special tools are stored for lending to Club members.

Cheers, Tony.

[Chris KC]

As Ian says, a die isn't really the answer if you can't get the thread started. The beauty of a thread chaser is the good threads guide the tool and keep it more or less on track. Though careful work with a slim file or blade is I'm sure equally good - depends on the degree of damage.

[Charles P]

I rarely disagree with Chris KC but in my experience a die is the answer.
However, you may need to tease out the start of the thread with a triangular needle file or similar to avoid the problems that Ian identified. The hub puller works so much better when it threads all the way on. A die is £42 delivered from Tracy Tools, so expensive for a rarely used tool but low cost if it revives a duff hub

[Ian Williams]

I think the point is that in inexperienced hands both either file or die alone can do a lot of damage. Yes I am sure in experienced hands a file/chaser alone will get a thread functional again ( I have done so myself ) however there is also a risk of removing too much metal and significantly weakening the thread. A die on the other hand, if you can get it started correctly, will only remove the flattened portions of the original thread (and would be my preference) however get it wrong with a die and you are even worse off then you were at the start. Which ever method you choose take care as is there is a lot of load imposed on this thread to remove a tight hub.

[Howard Wright]

If you have a hub that is really badly damaged David Cochrane sells new ones!

Howard

[Jamie]

I have had success cleaning threads by using home-made split dies or chasers. If you have a spare nut of the correct thread, cut through the side of the nut so that it can be levered open slightly or closed up, depending on what you need to do. Then case harden it with Casemite or whatever is available. This approach is no use for cutting new threads, but with care, is useful for cleaning up burred or damaged threads.

Jamie.

[Old Dave]

Thanks eveybody for the advice and the insights into the problems of century old design.

In the end, my friend (mentioned in the last thread) who knows little about A7's but an awful lot about metal saved my bacon, not for the first time. He spent half-an-hour or so using needle files and a small triangular file cleaning the thread and then the puller went on and did the business.

The afternoon has been used fitting the second spring with bolt and u-bolt. It gave me quite a fight, but it is there now. It should be finished soon.

Thanks again for all info.

Dave

[JohnD]

I have several hub pullers of various vintage, and what i have found is that if one doesnt fit, try another, and then one does tend to screw on - worth buying another puller when you next see one.

[John Mason]

When faced with similar problems in the past when it’s only the end/start that is damaged get a nut of the same size and thread. Cut the nut in half and place it on the good section of thread and hold it in place with a ring spanner. Oil the thread and wind off the nut moving it backwards and forewords until it moves freely and winds off.

John Mason.