I have a 1987 chevy 3/4 ton 4x4 4 speed manuel tranny 14 bolt rear end. There is a clicking sound coming fom the rear end. I lifted the rear of the truck put it on jack stands took it out of gear and spun my tires by hand while trying to pin point where the sound was coming from it was coming from where my pinion seal is also I could hold my drive shaft still while spinning my tires could this be my front pinion bearings? It only makes this sound sometimes.also my filler plug is the type that needs a 3/8" rachat end to get out but it is stripped out so there is no way to check fluid much less fill it. Also if it is the front pinion bearings do I have to take the cover off to replace them or just the flange and seal? Other than the clicking now and then the truck runs fine. Thanks.  

a quick fix for the filling problem of the rear is on ive had to use on the tral

 tak a large zip lock baggie and fill it with gear lube when to go to put the cover back on position the bag so the zip lock is on the out side but the bag is on the inside of the rear when you bolt the cover back on the bag will be ripped to shredds but the plastic will still be in there this should only be used if there no other way of filling the rear