Noisy u-jont installed by novice ,30 coupe

[31Abone]

Have noisy coming from trans area.kind of a thumping sound and also whines in 2nd gear but does not kick out 2 nd gear going down hill as one would think of loose trans bearings...I suspect u-joint bolt is missing or other ? what is best method to inspect u-joint ?? thinking of dropping rear axle and pulling it back is that correct ??..what happens if bolt is not install on u-joint ?? tnx much