Some Nissan Frontier owners report experiencing transmission issues, such as reverse not engaging and an inability to shift out of park, which can prevent the vehicle from starting. These problems may stem from common concerns like jerky shifting, premature downshifts, and overall shifting difficulties. Additionally, some owners have noted that cooling system problems can lead to transmission failure or engine overheating, further complicating the vehicle's ability to start. Drivetrain issues, including clunking noises and premature wear of parts, have also been reported, potentially impacting transmission performance. Furthermore, a rusty distributor shaft bearing may contribute to complications within the transmission system. In light of these issues, it is advisable for owners to seek expert advice and consult a professional mechanic or Nissan service center for effective troubleshooting and repairs.