i drove my camaro today and even though going from 2.56 open to 3.08 posi isn't a huge change, i can feel the difference and there is a little better acceleration now

I'm hearing the same groan though as with my old rear end. It happens above like 15-20mph. it's like a low groan. on my old rear I thought it was a wheel bearing but what are the odds of it happening on the new rear end too. It has my MT 28x12 tires on the rear too.I can't remember if they balanced the wheels when i had the tires put on. do you think they could just need to be balanced?

man i was hoping after all the work of swapping the rear and brake work that it would go smoothly but i guess that's not always the case with older cars :/ I really hope it's not a wheel bearing because i don't wanna tear into the rear again

 

alot of times the low speeds can be caused by the tires...when you turn the car left or right dose the sound get any louder? What kind of tires are the mt in the back, are they like a street slick cause those can be noisey when driving.

 

well it gets louder as i go faster and i think it helps when i turn left or right. The tires are MT SR radials

 

Did you double check the level of your gear lube?

 

Yes it is possibl to have axle bearings bad on two rearends when both are about the same age. I'd still do the easy stuff like Camaro 69 mentioned. Gear oil needs to be full enough to run out of the fill plug hole, when you remove the plug.
Sine Camaro bearings run right on the axle they will score the axle and require you to either replace the axle, or buy repair bearings that have a wider surface area and span the bad part of the axle.

 

oh man that would suck because after all the work of swapping them I would prefer not to have to dig into the rear again lol The gear oil should be full but when i first filled it I overfilled it so i drained a quart out until i stopped draining out of the plug. I'm sure I lost some posi additive so do you think I should add some more? could that be it?

 

Being too low would make the gears sing, but the posi additive won't affect gear noise one way or another. The additive prevents the clutches from sticking which gives you a chatter around turns. Add the gear lube slowly until it drips (slowly runs) back out the hole, then cap it.

 

the possible causes of the noise so far are:

low fluid (don't think it's low but i will check)
bad wheel bearings (which i really hope isn't the cause)
bad u-joint
wheels not balanced

 

if it is a wheel bearing, then doesn't the car growl or screech when turning. and Do i need to remove the axles when checking the rear wheel bearings or can i just remove the hub?

 

Getting to the wheel bearing is easier than you think, but yes you'll have to pull the brakes and axles to get a look.