I am having problems with the Allison in my 2005 Duramax. First of all it has 240,000 miles but is not raced. The temp runs about 20 degrees warmer than normal, sometimes it will not shift into overdrive and I will get a check engine light for a few days but it will go away. Ocassionally I will get a "Range Shift inhibited". I had a fluid flush done on it and they put a BG product in and replaced the NBSU. But it still does it. Can you reccomend a good transmission shop for these Allisons in the Casper, Wyoming area. Got any ideas on the "range shift inhibited" problem.
