young hottrodder need some advice and help

i just got a 56 4dr olds (love it to death )
and i noticied it gives a small jump when when shiftin it (park to drve that is) at first i thought it was just the regular hard shiftin of the hydros but when i checked it out i found some more than regular endplay on the drvshaft so i suspect the rearend.nothin to be worried about right now but will it get worst
dont really know to much about the rearend if that is indeed the problem what should i do o get it good
thanks

 

could be shifting hard due to a high idle. But more than likely its the combination of hight idle and worn out u-joint, or it could be the U-bolts that hold the reared to the frame. Just figure out which one it is and buy the appropriate part to replace it. Usually in a couple of hours if you know what your doing.

 

oh cool thank you i never really thought about the u joint gotta go check that
i already checked the ubolts there real tight
you dont think its in the rear at all i know theres sopposed to be some endplay but it seems like a lot to me but thats just me