I'm converting my 88 2wd to 4wd and was looking at the speedometer driven gear in the transfer case.

In doing some research, here's what I've found which I believe to be correct.

There are two types of speedometer cables.

Type one.
If you have cruise control, there is a speed sensor assembly that plugs into the transfer case. (Driven gear is mounted to the sensor unit and held on by a cir clip). The sensor has two connections. The speedometer cable plugs into one of the connectors and a two wire electrical plug which goes to the cruise control amplifier. So there are three seperate units. The speedometer cable, the two wire electrical plug and the speed sensor assembly. (This setup should work if you have cruise or don't have cruise). If you don't have cruise the two wire plug is not used.

Type 2
If you don't have cruise control, the speedometer cable is one piece and has a barrel end on it that the driven gear is held in place with a cir clip. the unit just plugs into the transfer case.