My last Volvo 770 was automatic; got stuck many times, lots of glitches, towing, waste of over 20,000 $$ in trany repairs in 3 years,that's why i sold it; My present truck , got it new, the dealer was trying to push his autoshift, told him, No THX! i have Eaton 13 manual; over 1 million miles; works fine all i did for this is oil change. If you are an O/O and pay the maintenace bills, stay away from automatic, especialy if you buy used truck without waranty. Imop, Eaton 13 speed manual is one of the best reliable transmission ever built.
If you have some $$, and planing to keep the truck, take it down and instal a manual . You should find a used/remanufactured one instaled for less than 10,000$.