... are as below:1. TM model are chain drive TMZ model are gear drive2. TM model, the 3 point linkage ... TMZ180, the middle gear box of TMZ model(new model) and TM model are the sameBut from TMZ190 to TMZ230, ... models and TMZ new models are different.TMZ model rotary tiller(Gear drive).The 3 point linkage ... (Gear drive). The 3 point linkage of this model can be moved by adjust the screws. ModelWorking width ...