it sounds likethe pilot bearing in the crank is giving up..requires pulling
the tranny and the flywheel and some real fussing to remove the bad boy..it
will start to "grab" and then go <bang> and seem to clear up ..except then
you will get clutch jutter on takeoff and the input shaft seal on the tranny
willl soon give up and you'll start leaking 90wt oil  on the ground and
clutch....

Steve

"Hey! nice Jeep, Mister! "
"Look kid, it's NOTAJEEP! "