Crossthreaded oil drain hole on lower unit.

[wassajet]

Hi, i have just replaced the gear oil in the lower unit of my 1970 evinrude sportwin & accidently cross threaded the thread on the bottom plug hole & it's now leaking. Is there a way to rectify this problem without having to replace the lower unit casing?The thread on the plug is ok it's the thread inside the casing that's been crossed.All help will be very much appreciated.

 

[racerone]

Carefully line up a 3/8"-nc taper tap and see if you can pick-up the thread and " recut it ".------------------Perhaps your local machine shop will be able to do this , should not take but a few minutes.

 

[vics]

If you can re-cut the thread you are in luck but you will have to be very careful in the future. It will always be easy to pick up the crossed thread and if you over tighten it you will strip the thread.

Helicoiling is the way forward if you cannot satisfactorily re-cut the thread or if you subsequently strip it out.

As an emergency measure put the plug in using PTFE tape to seal the threads.

 

[wassajet]

Thanks for the quick replies,a mate of mine has the tools to recut the thread, i'll let you know how it goes. Just out of curiosity, what is helicoiling ?Thanks again...

 

[vics]

Helicoiling:

http://www.youtube.com/watch?v=RFYa6sjhh_E

 

[wassajet]

Thanks Vics that was very interesting, you learn new something every day..

 

[wassajet]

Sorry,that was supposed to read something new every day.

 

[wassajet]

All's well, was able to cut new thread without any problems or leaks. Thanks again.....