INFINITY

i just did the 5 speed tranny swap (L52) into my 80 4x. the problem is now if i am going any speed at all over 3-5 mph and try to put it in 4 high from 2 high it grinds bad and i cant get it in???? BEFORE THE SWAP i could shift on the fly from 2 high to 4 high going up to like 50 mph.
if the rear wheels are moving at all i can feel the gears bumping over each other as i shift. i am stumped ???

INFINITY

crap i am dumb sometimes....needed to lock my hubs. works fine now