Big brake install issues...what have done

[BADBOSS]

So I went with the Steeda 13inch rear brake kit and the Hawk HT 10 race pads. Install seemed to go well, taking the axles out was easier than I thought, The biggest PITA was cleaning the old seal off the differential cover. Anyways, I take it out and follow the break in procedure on the pads and everything seems fine. I do notice the rear wheels, and pads are much hotter than the fronts after the break in drive. I park the car with out the e brake to allow everything to cool. Next drive I notice a slight groaning in the rear end of the car at slow speeds, so I put the car up on the stands, double check everything, it looks good so I go for another drive thinking maybe the pads aren't broken in yet. Take it up and down a awesome mountain road a few times aggressively, everything seems fine brakes seem stronger than stock! Bring it home and the groaning is worse. Could these new rotors be warped? Could running racing pads in the rear and stock in the front cause the rear rotors to warp in less than 100 miles?

Any thoughts appreciated...

 

[4.SLOW]

I'm assuming the steeda brake kit requires you to remove the anti-moan bracket attached to the rear brake caliper brackets? Its the u-bolted piece wrapped around the axle.

 

[stangn]

You did refill the diff with new gear lube and friction modifier right.

 

[BADBOSS]

Yes, refilled with Royal Purple and friction modifier Yes I had to remove the anti-moan bracket.