Is the adjustment sleeve the right size? If you aren't familiar with the way the adjustment sleeve works as you turn it, it pulls/pushes the two pieces of the tie-rod closer or further apart. Given how it works, even if you were to machine more threads onto the tie-rod end, it will basically bottom out against the other part of the tie-rod(end that connects to the steering relay rod).
Bent idler or pitman arms, and worn ball joints can cause wear issues, and play hell w/techs who don't understand front end suspensions.
