After 10 years or so of use and one trans change, I removed a control arm to make an adjustment and could not turn the threaded portion into the solid shaft. Tried everything possible but really could not move it more than 1/4 turn at most. Hard for me to believe, but I'm thinking pounding of threads together inside shaft, due to using a drag race prepared 700-R4 trans which shifts very very hard at even low RPM must have somehow distorted them so the male and female threads are locked together. Looking for a new set of control arms but do not find them available anywhere on the inet. If anyone knows where I can buy a set, I would appreciate the help. May have to resort to hacksawing the threaded portion and inserting a short steel pipe coupling so I can make adjustments at the coupling.