OK GUYS I NEED SOME HELP WITH MY REAR END ISSUE

[GODSPEED]

Ok a little story first, about a good week ago i was on woodward and a two mustangs i guess wanted to races me so we did and i was gone from the the start lol but to tell you the truth i dont goose my all the time more like once in a blue moon, so thats why i need some help, when i got home i backed my car in up my driveway and i heard a ticking noise from the back of my car i thought i blew my rear end but it drives fine until i back up some where so i took the car down to DRIVE TRAIN SPECIALIST and they took it for a test drive but told me nothing is wrong with my rear end its more likely my torque arm bracket bushing so i looked under today but could not find a issue with it. BUT a issue i did find but only on the back driver side tire when i spin it in reverse i hear the the ticking noise but when i spin forward there's no tick or any kind of noise for that matter so can any one tell me there thoughts about it i need some help before i go a spend money in the wrong place.

[Slomaro]

ujoint? maybe not sure you said you took it to a shop so if they say nothing wrong i would take it to another shop for another opinion