High pitch squeal coming from the rear axel

I have a 2001 Toyota Tacoma 4wd double cab.
So here is my problem, during the summer I had a seal replaced on the back right wheel. A month later I noticed that it broke again but did nothing about it. I forgot about it right about a month ago. Unfortunately the guy that replaced only guarantees it for a month. I figured out the breather was clogged and wasn't allowing my diff. to breathe.
A week ago I noticed that the rear end wasn't leaking any fluid out of the right side. The same day I noticed a very high pitch squeal that sounded like it was coming from the rear end. I jacked up my truck and spun the tires and heard the squeal but it was really soft (which I expected). I am thinking that the bearing that is on the right side is shot but I don't know for sure. I put fluid into the diff to see if it would lubricate the bearings and and stop. It hasn't and I think it has gotten louder. Could it be the seal making the sound or is it definitely the bearings?

Plz help. I am going snowboarding tomorrow and need to know if it is ok to drive almost 100 miles away.

 

If the seal was leaking for a while and then it stopped leaking, the differential ran low on oil. If you're lucky only the axle shaft bearings are ruined and they're relatively quick and easy to replace. If you're unlucky, the ring and pinion bearings are ruined and your differential will have to be rebuilt. You should only drive it to the nearest shop.

 

I am going to take it to my auto shop at my school on Tuesday to see what the shop teacher thinks about it. What would the most likely of those two things would it be?

 

Is there anyway to check to see which one it is without taking the axel out and checking it from there?

 

So how does the wheel bearings get ruined if they are sealed bearings???

 

I put my truck up on the lift and discovered that the sound is a bearing inside the differential. I figure that it is the carrier bearing because I am 99% sure that my axle is bent from when my truck was tipped over a year ago. That would explain why my seal would keep failing.

Should I just get a used rear end and just do a full swap or just get my differential rebuilt and a new Axle?

 

If you have access to the school auto shop, I'd pull the rear end apart since you need bearings anyway and do a string test or take measurements to see if the housing is actually bent.

 

The only bearing(s) that I need to replace would be the ones in the differential. And how hard is it to replace the carrier bearings?

 

I think that I solved the problem. When I put my truck up on stands and had somebody step on the gas, the problem was the carrier bearing. It had a ton if play in it. Replaced that with a new one and now she runs as good as new.