9 inch. whine ? What to do? Hear is one thought.

[2ndgear]

Just install the 9 inch. back in car and it has a slight whine to it. What are some thought on pulling the pinion assem. ahead about 1/2 inch to change the shim. Most likely would try .003 more and test and then .003 less and then test. I am thinking of cutting shim in half to install it. Once the back lash is set it will not change by moving the pinion in and out a bet. So there should not be a oil leak because of the o-ring that is there. All the bearings are new and the preloads and back lash are correct. Will it work? Thanks in advance.

[Falcon67]

No.  Any change in shim on the pinion will change the backlash.  And without a pattern test, how to you know +.003 or -.003 is the number.   And no need to cut the shim, the whole assembly will come right out.  What's the ratio - low ratio (high number) gears whine some by nature.