boogiewoogie

havent drove my truck in some time (89 4r 22re)but just got her back on the road after i sas'd it but ive had this problem since before i did this work. awhile back i was camping had about 3 ppl and gear in my truck . i decided to see if i could wheel up a steep hill in rwd with my locker it was going but i kept hearing banging right under shifter/rear aux heater it was odd so i backed off checked didnt see nothing crazy popped in in 4 low and went up didnt have a problem after that. but ever since then i was dd my truck and sometimes leaving work in the cold weather .id accelerate on the highway 1st gear would rev straight up id go nowhere id immediatly back off then it would catch and bang! this was a loud bang and thump enough to make all the dust from dirt float in the air id pull over and nothing .drove home fine. now im really concered since its warm out i wanna drive this thing. i drove it to work the other day no problem but when i was coming home i accelerated out of a turn it made the thump wasnt too harsh but cant seem to figure it out. driveshaft seems to be fine no slop .transmission mount seems ok i push on it hard with my foot small movement but figured thats ok with the mounts being rubber. dont know where else to look gonna replace shifter solnoids to see if it helps in the slightest but dont think that could be it. sucks cause i cant find another a340f anywhere to swap in and really do not want to go to manual unless i can find a alternative with the trans to stick to manual and with the ecu. any body ever experience this or have suggestions?