The freezor part of our Maytag side by side fridge is not freezing as it use to.?

Our fridge (Maytag, side by side GC2227EAD5) is having problems. The refrigerator is perfectly fine, but the frezze is not getting cold enough. We recently replaced the defrost element. The fridge is 6 years old. What life would you expect out of this fidge? Never owning a Maytag before, are they worth fixing? What could be going on?