Had to rebuild my front diff over the winter and havent had a chance to put alot of miles on it (maybe 100 or so) it's already getting noisy. I jacked it up and ran it in 4wd and the front diff roared louder with speed. When I rebuilt it took a pretty thick case side shim to get it to spin freely by hand when the cover was bolted on. I'm wondering now if I should have put a thinner one in meshing the gears tighter and not worried about how easy the pinion turned by hand. I put a one size thinner shim in today and the gear noise is still loud. Should I use some of that gear paint to see how the teeth are meshing? Will it work on straight cut gears? I used my original cover but had to replace the case, so what shim should I have started with on the case side? The book says a 1.3-1.4 but I couldn't turn the gears by hand once the cover was bolted on.