I have flat towed my 84 4x4 pickup for about 3 years. I have lockers front and rear, twin cases and I just put it in 2wd, and the 5 speed in Neutral. I did for last years tinbender's jambo and have never had a problem. The rear locker spins the drive shaft but I am only going 55 mph, no lock up and no adverse transmission problems. 8) 8)