Little bit of a whine in rear diff when I let off on gas

[jtkaaa07]

I recently did a mini tub spring relocation on my dart, after I shortend rear end and put back together theres a little bit of whine in the rear end, which goes away one I accelerate a little, wondering if it could be my pinion angle is off a little, what do you guy's think? I know that there are shims available to correct pinion angle, just want opinions on this.
Thanks

 

[RustyRatRod]

No it is the pinion gear depth that's not quite right. It either needs more or less......I can never remember which. You might try checking the pinion nut to make sure it is tightened properly though. That can affect it as well.