thrust button/shaft

some thrust block halves are held together by a split roll pin -- easy to drive out with a pin punch --- you probably have one that the pin is like a long rivet and is peened over on one end after it is installed to lock the two halves of the block together -- look at the thrust pins on Mancini's web site to see what i mean --- you will have to drill/remove one end of the peened head off and the center pin will fall out -- shortening the axle is easier.