my rear engine mount is fucked anyone have any ideas on how i can fix it

its not so much the mount more where the mount bolts to the chassis thats the problem
the thread that is inside the chassis has come loose from its tacks and wont hold the bolt

anyways ive had this problem before and my mechanic figured a way to get a bolt in there and instead of screwing a bolt into the chassis you thread a nut onto the bolt to hold the engine mount on. I should mention its the rear torque mount

so it seemd to work quite well so i was wondering how he got it in there seeing as there must be something holding it on inside the chassi

any ideas would be greatly appreciated


edit: this is the one i mean