Last fall, suddenly my 2013 ST LTD got stuck in 5th gear. Couldn't get into neutral or any other gear. Limped home in 5th but where there was a incline of any kind it was get off and push. Finally got it to the dealer in Spokane (250 miles away-closest dealer) and he claimed to have fixed it. 'A linkage', he said had come loose. Got it back and parked it for the winter. Pulled it out today, 2/28, and rode 100 miles when it got stuck in 4th gear. Either he was a terrible mechanic or it is a design flaw. I have 31000 trouble free miles on the '13 but now this issue. I do not have a shop manual and don't want one but am willing to try to solve this on my own. Any ideas and where under the plastic am I likely to find this "linkage" issue>?