Whining rear end
 

So my car has always done this and i can post a video if needed but heres the story

in regular drive anywhere from 35+ miles an hour if you let off the gas the car feels like it is engine braking almost its being like pulled back, and the rear whines loudly like wooooooooooooo type of sound, this sound is not present when my foot is on the gas

if i shift it into Overdrive it doesnt pullback/brake as much but it still does and makes the whine sound a bit

and lastly if i shift it into neutral it does it just a little bit less than it does in overdrive (which isnt much btw its really only bad in drive)

my question is what does this mean?

is my rear end bad? should i get a new one? im looking to upgrade to 3.73's so i wanna know if im gonna need a new rear as well

It's your gearing. If you put new gears in you'll be fine. Changing the oil will also help the whine go away. It'll slow done in drive and over drive as the engine is acting like a brake. But putting in new gears or taking your assembly out and reshimimg it you can reduce the gear whine.

alright sweet, for gears where should i buy from and what all should i get, im a noob when it coems to gears, i also already have a gasket for it, and ive heard royal purple is the best for oil

Sound like a pinion bearing to me not gear whine.

^ explain please :)

Yes it could be that aswell. You can get Richmond gears but they are a little noisy. Can't remember the other brand out there. You'll want a shim kit aswell. When I get on my computer I'll post a link to a write up for installing the gears and shimming them. If you try the search there might be something on this forum aswell. Also when changing the gears you should chsnge out all the bearings and seals.

alright sweet, i need to learn this stuff ive been gettin a little cocky lately with suspension and engine related stuff and i finally fell on my face tryin to figure somethin out lol

Rear end gears will make that kind of noise when backing off if the oil level is too low, been there...had that. Check that first.

My rear end whines all of the time. I just refill it with oil and tighten the bolts.

My rear end whines but I changed the oil and it got quieter. I also got another rear end but that's because I wanted 4.10 gears and posi. But that rear end also isn't installed.