ATF drain plug stuck?

[freeflight]

Hi there,

I was doing a drain and refill of the ATF. When I took the drain plug off the pan, it took several turns with a wrench then the bolt became lose enough to uncrew by hand.

I was very careful to put the plug back in, but I can only twist it in a little bit by hand. Then it is stuck. There is still plenty of stud left outside the pan. I didn't push it further by using a wrench, worrying about damaging the thread. Tried a couple of times, same results.

The plug bolt thread looks fine to me. Am I suppose to use a wrench from there or the thread in the pan is damaged?

Thanks,
Kevin

 

[Morphyne]

Use a socket wrench and just be gentle. If it's not cross threaded you should be fine.

 

[freeflight]

Inspected the plug thread again today in better light, it was stripped! A new plug did the trick. No leak so far.

I don't understand how the thread was stripped. I used a torque wrench to tighten it to 20 ft lb last time. Is it because I unscrewed it when it was still hot?