wooohooo i think i can help someone at last.....had the same problem.....took both motors off, took everything else off around the steering....turns out that there is a metal ring surrounding the shaft, it grabs hold of the shaft to much and stops it extending....its split so you can get a pry bar in there which i did and move it slightly,,,grease it up,,,,lots of gt85 later and all done..had it for a year now and the problem has not returned...
hope this helps matey...