steering coupling??????

The shaft is two separate pieces. An inner and an outer shaft. The inner shaft is held in place by some nylon set screws. In an accident, the set screws break and the shaft collapses.

I assume you are saying that you want to pull the inner shaft out a little farther so the over all length of the column is longer...correct?

There are two different length shafts...one for power steering(shorter shaft) and one for manual steering(longer shaft) It sound like your new column came out of a power steering car and is now too short.