Anyone have differential cover probs?

[CobraRed_96_GT]

My rear end shop guy says he offen sees problems with mustang rear end cover after a good amount of miles on a powerful car. I was like on a 8.8? I've never heard this. He wasn't trying to sell me one, just suggested i get one soon cuz of my 4.10's. Anyone have this prob?

 

[RoadconeTuning]

aparently you can twist some stuff, so people put on the girdle covers, just seems like some cheap insurance to me, i plan on putting one on my car next time i change the diff fluid...

 

[bakos24]

I have a trickflow one and no problems here.