Check wiring first
Before disassembling the dryer, check to make sure you're getting 240 volts at the receptacle or terminal block. You should have 120 V between each hot line and neutral or ground, and 240 V between the hot lines. Many times when a dryer will turn, but not heat, it is because one of the fuses is blown, or one side of the circuit breaker is bad. Most dryer motors operate on 120 V, so if the side it's on is OK, but the other isn't, it will run but not heat. But if it's the other way around, the dryer won't work at all.