FRUSTRATED! need help with carrier swap

in my old carrier the thrust block had some play in it this thurst block thats in the carrier has no movement in it ive tried putting a dowel rod down the axle and watching both sides with help to see if it moves.... it does not move could that be my problem?

I've never saw that happen but I suppose something could be wrong that has the thrust block jammed. You'd have to pull the carrier to have a look see.