i just got done installing my nine inch rear, 3.89 gears, ford posi, moser axles. I started it up to break it in on the jack stands and it starts making this loud squeek instantly, its definately from the pinion forward because it makes the sound every time the driveshaft passes a certain spot, not the wheels.
I got under and moved it by hand and the noise seems to be coming from the pinion, like the front of the pinion.

it sounds like when you have a clean tupperware container and a clean thumb and you drag your finger across it, that squeek sound, its doing it once every driveshaft revolution. Turning the wheels by hand and I can feel some extra drag when it makes the squeek sound so its definately something rubbing or something. It has to be internal, I am positive nothing but the pinion is making the noise.

Could that little cover plate behind the yoke be rubbing against the seal and make that noise? i think mine has a little spot where it is bent down some but it looks like that is there on purpose.

anyone that knows these rears out there? how about a possible worst case scenario if i drive it like this... a reasonable one

 

damn, not even a view?

 

Find the squeeky spot, put finger on little shield, turn, if you feel a vibration then you need to bend shield

 

Is it possible the seal got bound up in the bearing?

Is the pumpkin filled with lube and is the pinion down low enough for fluid to get up into it?

If your feeling resistance by hand, my thinking is you will have to tear down the pinion. You could start by loosening the yoke and taking a look. Try to pull the pinion shaft and rotate see if you feel binding, then push it in and do the same thing to see if its the rear side or the front that is binding.

If the tight spot is in the same spot on the pinion's rotation, I think you can eliminate the ring gear and beyond as being related to the problem.

 

ok i took apart the U joint and lubed it up it was dry, and the noise was still there but not as loud.. i said hell with it and drove it and within a matter of 5 miles or so the noise just went away.

the 3.89 gears are one of the best mods ive done for this 305, 3.42s just needed too much torque for this little motor to handle it pulls soooo damn hard now i think i might hit 12s... launching is rediculous too, i broke my torque arm yesterday on the street . If its not one thing its another!