ok i wouldnt suggest doing this if the axle stays in place.
but if your rear axle starts to become loose this is a great mod.
my buddie who is an ee and an ex drag racer(coronet rt) were setting up a messed up obsticle course the other night ago and man it started out as a good night until the rear axle on one of my cars started to strip. he was like here and took the chassis up to a soldering iron and he melted the axle holder around the axle and kept playing with it until there was almost zero slop in the axle. which in turn keeps the motor running smoother with less vibration. which in turn gives you better torque and speed. especially in turns. which improves handling as well.
then after fixing that we were set up to drag race to test the rear axle vs the unaltered car and he was sweeping out the hallway(dragstrip) and he stepped on the unaltered car and snapped off the rear clip that holds the body to the chassis. so we took the rear end of another chassis and used jbweld to put a new rear part on. this worked pretty well.
so its been a long weekend of fixing and modding. now i have 2 working cars again. hehe
jbweld = bondo for bits
http://www.jbweld.co.uk/