Whining noise after doing 5 lug

[2slow2go]

So last weekend i did a 5 lug conversion on my s13 with new conversion hubs. I also changed it to skyline brakes up front.

After being done I took it for a test drive and noticed a whining sound from the rear .. especially when i turn. Does anyone know what it maybe?
I didnt use a torque wrench to torque down the axel/hub but just used my air gun. Could i have overtighten the bearings?

thanks in advance!