As a preface ... I used the search bar with 6 different search combos ... the search bar is not the greatest.

Nevertheless, to the issue at hand.
I was changing the gear and transmission fluid yesterday during which I rotated the drive shaft to see how much play there was in the rear-end. The transmission was in neutral and both were filled.
The drive shaft rotated probably 4 degrees either side before tension was felt (~7-10 degrees total by estimate - using one of the rear drive shaft bolts as a reference).

How much slack should there be in the diff with 4.57 gears installed?

It's an '04 diff with a total of 12,000 miles on it to date (with the 4.57 gears installed with 24 miles on the diff originally). The diff was professionally built.

Thanks for any information.

 

Since I have never tried to do what you have done, I don't know what to say.

I know that realy the only way to inspect the diff is to remove it from the car and open it up. Then you can test preload and measure back lash. At this point the back lash should be .008. the rest of the spec can be found in the Helms manual.

 

Thanks.

The reason I was concerned is the stock diff had very little to no play.
I spoke with Jeff G on Friday and he mentioned the 4.57 gears have significantly more play than stock. I'm getting some work done at his dealership next month, and his diff guy (who built the diff) will take a look at it then.