How many u joints in a 1990 dodge dakota 4wd.

Hello, the front drive shaft should have 1 on each side (2); the rear should have one at the differential, with the possibility also of a two piece drive shaft, adding 2 more.

IF you're having noise / vibration problems in 4x4 only - the FRONT propeller shaft has a constant velocity joint at the transfer case that commonly causes this concern. Otherwise it should be obvious how many actual “universal joints” are present..