I *think* I am having some rear diff problems. I have a diff that has leaked for the last 15,000 miles over the past 4 years. I don't drive much. Anyway, I have been trying to kill the leak. Started with a new pinion seal, no dice, still leaked. Then a new pinion flange - Still leaking. I can also see fluid coming out the driver side of the 3rd member. So, I know I need to pull it and RTV that seal. I recall freeing up the breather at one point, so I am afraid that it forced oil out through that seal for some time before I knew anything about it.

Also, When I replaced the flange, I reused the pinion nut and torque'd to spec which was several turns more than what it was on there at to begin with. When I did this, I had the rear of the truck up on jack stands. I tried to turn the wheels and at a regular interval it would bind, just a little bit. It would rotate on around, but it would definitely bind up at the same point everytime. So I backed off the nut a turn or two and it seemed to rotate freely. I left it there and have put maybe 2k miles on it since then.

Truck has 166k on it and I have 31's on it now, though I want to go bigger, but not radically. Has to be streetable.

I am looking for recommendations - Should I get a junkyard diff and then pull mine to see if it is busted? Or just pull mine and have new qears put in it, if they are indeed busted? Thing is... if I regear the back, i gotta do the front too... and that means more money...

also, a junkyard about 2 hours away has 4.56 diffs, front and rear, from a v6. Is it okay to swap that into my 4 cylinder?

Thanks all!