Luff Cover Fixing bolt... thread stripped

Having been faced with the problem of a stripped thread on the bolt that holds my cover plate to the mast I needed a cure.

This solution places a M8 threaded insert in to the main body of the mast. If your fixing bolt is not M8 you may consider drilling your plate to accept a suitable bolt.

Here you can see the hole prior to the repair and with the plate removed. Notice how thin the metal is and it is no surprise that the thread has stripped.




To make the repair you will need a 14mm ring spanner to tighten the insertion tool and drill bits suitable to enlarge the existing hole to 11mm. I chose to work my way up using a 9mm then 10mm and finally an 11mm. This reduces the amount of internal burring.

Be careful to drill only deep enough to go through the metal of the mast and not to damage any cables/lines in the mast.


You will then end up with a hole that will accept the insert



Once you are happy with this the insert needs to be fitted to the tool. Loosen the locking nut at the back of the tool and wind enough thread out of the front. Do not unwind too much as once again you do not want to damage any internal wiring in the mast. But do ensure you have a couple of clear threads so that the tool has a good grip on the insert.


This picture shows the tool fitted with the insert and with the tommy bar inserted.




Next insert the assembled tool and insert in to the hole.







Use the bar to hold the tool steady and start to tighten the spanner. You feel the insert start to tighten in the hole as you do so. Once the insert has started to grip to the point where by the tool will not move if you try to move the tommy bar, turn the spanner a further half turn. Do not over tighten as you will strip the thread of the insert.

Now loosen the back nut a fraction and then unscrew the whole tool from the insert. Leaving the insert firmly fixed in the mast.





Job done.

If anyone wants to give it a go I have the tool and spare inserts... give me a shout