Not just red loctite, a whole lot of it. I put my shift knob on without the lock nut and covered all the threads on the shifter and inside the knob with red loctite. I thought red was the weaker one.

 

Yes. The Red Loctite is heat activated. After it sets and dries, you basically have to melt it to get the threads to move. I does not take a whole lot of red-hot heat though. A hairdryer will work. If you are talking about a metal shift knob, I imagine that just letting it sit out in the direct sunlight for an afternoon might just do the trick...

Andrew