1993 Jeep Cherokee right hand steering lock

Steering problem
1993 Jeep Cherokee 6 cyl Four Wheel Drive Automatic

when using right hand steering lock it is very stiff as though no power steering, left hand lock is fine, have greased all steering nipples and checked all visible steering joints, nothing obvious, a forum suggested the serpentine belt which is new could need tensioning, but would this affect only the right hand steering. Many thanks in anticipation of an answer