i have blown up the 8.8 in the rear of my 86 F150 two timesin about 15 months. Both times it has been the spider gears, center pin, and the carrier that have went south. i do not know what could be causing this problem. the gears are not set bad so that isnt the problem. when i removed the passenger side tire and drum, it was covered in grease. it didnt have the smell of gear oil so i dont think that the seal is gone, causing loss of fluid.

anyone have any suggestions as to what might be causing this problem?

thanks for the help

What differential are you running? Open, LS, locker or spool?

My factory traclock worked well but had a lot of slop in it. It almost felt like it was shifting gears. I drove on it for a long time like that and it never failed. I did check it out and found that the pinion shaft holes were ovaled and that because of this the spider gears would rock, actually pulling away from the differential case approx 1/8". Needless to say I am no longer using that limited slip. If all this trouble is with a factory differential I'd say upgrade to a locker and you shouldn't have any more trouble. I am running an ARB in mine now.

Could the housing be bent?