got an 87 TA with a leaky rear. I ruined the posi unit on the stock 2.73, so i bought a 3.23 posi-disc off a 91 camaro. The pinion bearing went out of it a coupla months ago, so i replaced pinion bearing (front only) pinion seal, carrier bearings (both) and put it back together. Now it's starting to throw some grease from the pinion again, could it be my other pinion bearing has gone bad? (it was good when i replaced the other one) or do u think that my pinion nut isn't tightened properly? BTW the car is a 700r4 auto with a slightly modded 305 ie dyno max catback, cold air intake, accel plugs, wires, cap, rotor, it's got a cam, and it's bored. It now runs mid to high 14s.

 

Did you grease the lip or the new seal? Check to make sure the pinion is tight. You may need some sealer on the splines of the pinion gear and yolk, slight leakage can seep through there.