AW-4 in my 96' cherokee is acting up on me. When cold shifts perfectly fine until everything reaches norm. temp and then wont shift out of 1st unless you play with the throttle and when it does shift 9 times out of 10 it will skip 2nd and go straight to 3rd. Overdrive and lock-up functions are smooth no matter when being drove. Does anybody have any ideas what would cause this and what the fix would be??? It all started when i changed the filter and fluid and it seems to be ok for about 25 miles each time fluid is changed out....has me puzzled but have not talked to a shop yet. Was hoping there would be a cheaper fix Ideas anybody?