Allison transmission noise and loss of powewr


#1

I am experiencing a loud noise and loss of power while towing my fifth wheel trailer. When the dash temperature gauge shows about 195 this whirring noise often comes up. During our last 160 mile trip, this problem occurred at least 30 times. Two different GM dealerships have checked and found no codes thus they have no idea how to fix this problem. Has anyone else experienced a similar problem?