Towing Issues: 2002 Ford Explorer 4/4 towing problem, electronic lock, ford explorer

Question
Hi I had my truck towed about a week ago to the dealership and the day i got it back my transmission has been slipping and i have had no problems of such before it was towed. I was told that my truck should only be towed on a flat bed and it wasent. It was towed from the back. I would just like to know If that is a true statement that 4/4 vehicles should only be towed on a flat bed. Thank you very much for your time i look forward to your answer or advice!

Answer
In general 4x4's are usually towed on a roll back or flat bed. You can tow a 4x4 from the rear as long as the differential/transfer case is in neutral and the hubs are not locked. Does your vehicle have electronic lock or locking hubs? If you had no problems before it was towed then there is a possibility, however uncommon, that it could have caused some damage.