stuck in 4WD on 1990 Dodge Ramcharger

Had to remove left front axle to change ball joints now left side stuck in 4wd ?

Double check your work, something was effected from the repair. Man made problems, which this is, are the most difficult to diagnose because the problem is not a normally occurring failure, so there are not normal diagnosis techniques. It will require someone to be able to look at this and access the situation to come up with a solution.
Good Luck!