So I did my differential fluid exchange, when i took out the cover i saw a metal piece which looks like it broke from the magnet, no damage inside diferential all theets were complete but a couple days after, a humming noise came and idk. Still drives normal. Don't feel any difference i just don't like the noise. Anyone knows if maybe the differential went bad? Can it be repair? If not I would like to start doing some upgrades to my car so is there any type of differential different than the original than fits and gives better performance to the vehicle? My Idea is to swap engine and transmission in the future so if I have to buy a new differential I better get the good one for when I do the swap. Any recommendations, comment's? Advices?

Thank you.

 

Does it just hum when you're coasting?

 

No, it doesn't. Only when I push the gas. It used to do it more after 50mph today started hearing after 20mph only when pushing the gas.

 

Looks like your car is a six banger so probably not a posi rear but it could be.
If it is it requires poislube added to the oil.
There are a number of better difs available but unless you are planning on big power don't waste your money.
I have a 2001 SS making 400 hp at the wheels and still running the stock 10 bolt posi,sees plenty of hard use too.
If your car is a six and you are planning a V-8 swap I would steer you towards just selling the car and buying a Z28 or SS.
It can be done but there are many headaches involved and in the long run you'll be money ahead even if you buy a Z with a bad motor or trans or both.
At least it will be a simple rebuild or bolt in replacement , a V-8 means a new K-member and a lot of computer/wiring headaches and more.