Transmission?

how do I know that it is in fact my transmission mount is messed up...besides the fact of taking it to a mechanic...or the fact that my transmission jumps when it shifts in high gears|||i would make sure its in fact the tranny mount and not the engine mount. simply lift hold and rev engine see if it comes up too far.it also depends on car camero and firebird has a sway bar from tranny to rearend that went bad at tranny offend|||The higher the gear; the harder it is for the engine to twist the input shaft of the tranny. that means it strains against the mounts all the harder. It's an EZ repair. Fix it before it trashes U-jointrs, speedo cable, etc.