1991 Chevy Silverado cv axle keeps tearing at the boot

I have a 1991 Chevy K1500 Silverado. The truck has a three inch body lift. I have had many problems as of late with the passenger side CC axle. I have put three brand new ones in as well as a wheel hub assembly. The wheel hub and one of the three axles were done at a repair facility. However after a month or so each of the three axles has developed a tear in the boot closest to the flange, not the wheel hub but the flange end. What could be causing this? I have no problems on the other side of the vehicle the drivers side. I have 33 x 1250 tires on fifteen inch rims ten inches wide. I notice nothing is close enough to this area to rub it or against it. But would like to know how to fix. Thank u for your time