I installed a used lock right in my 27 spline 8.25. I was told the springs were new but I am having second thoughts on that. Everything seemed fine initially. Now however there is lots of poping going on. Sometimes I will be driving straight and it will lock 2-3 three times in a row. Each time making a loud bang noise. I followed the installintructions to a T except for measuring the gap in the plates for shim thickness. I just reinstalled the orriginal shims. I used a 75-140 syntehtic and my tire pressures are set with a digital gauge. Where should I go from here????