I'd make sure the bracket connecting the transmission and shifter isn't loose first. My 2000 is notorious for this.
To connect the transmission shifter linkage on a 2007 Nissan Xterra, start by aligning the shifter lever in the neutral position. Then, attach the linkage rod to the transmission lever, ensuring that it snaps securely into place. Use the retaining clip to secure the connection, and check for smooth operation by moving the shifter through its range of motion. Finally, ensure all components are properly fastened and free of obstructions.
install transmission shifter assembly
The shifter cable connects the shifter to the transmission.
This should be really simple, if you've already removed all of the bolts which hold the shifter in including the one behind the shifter hole in the trans, the shifter should slide right down into the transmission (provided the transmission was in neutral when you pulled the shifter)
Remove the shifter cable and switch from the drivers side of the transmission and the seal will be driven over the small shaft and into the transmission case. The shaft is the one that the shifter cable hooked to.
Gear shifter or manual transmission.
no
It sounds like the transmission shifter linkage is disconnected.
You don't , you replace the linkage cable from shifter to transmission
If you look on the hump in the middle of the car near the back seat. it should be right behind the hole where transmission leaver and the gear shifter connect.
For an automatic transmission, check the side of the transmission by or at where the shifter linkage goes into the trans. For a manual transmission, check under the shifter boot.