OK thats good. Your luck is holding then.

Some facts. A threaded rod subject to high cyclic tensile loads is a fundamental suspension design compromise which needs all the help it can get to survive. This design shortcut is not now used in vehicles anywhere that I've seen in a long time.

Cutting additional thread on a lathe (or worse still with a die nut) does not improve its durability. Its not a matter of if it will fail - just when it will fail. The time to failure is now dependant on the skill of your machinist and the quality of his equipment.
Compromising the compromised design further and the cycles to failure reduce even more.

Feel free to disagree. I'm really only concerned someone will hurt themselves or worse still hurt someone else.
In the meantime this may be worth reading. http://www.resnapshot.com/MD1298.htm