A bad transmission gear can cause your 1999 Nissan frontier to shift hard. Low Transmission Fluid can also cause the transmission to shift hard.
Check the transmission fluid on the 1995 Nissan Altima. Bad fluid can cause the transmission to shift harder on parts that are more worn.
its a Nissan for starters but it could be the plug wires or the plugs or the distributor
electronic solenoid
a bad radiator -automatic portion of radiator not cooling off transmission
The most common cause of a automatic transmission jerking, when shifting, is low transmission fluid. Fill the transmission to the full mark.
Possibly low fluid.
If they are vacuum operated then it could be the hubs.
Your transmission is breaking down inside. ether watch for it. or extensive transmission is required.
There are several causes that an automatic transmission will not want to shift into second gear. The two most common causes are transmission pump issues and trouble with the vacuum modulator.
could it be low fluid
low gear oil or gears are worn.
The low pressure switch will do that when the system is low on freon.