can anyone tell me what pinion shim to use???

im having trouble puttin a gear set in my 04 psd with the 10.5 rear. its a used gear set out of my buddies truck with only a few thousand miles on them and they didnt make no noise and worked great. they are yukon 4.30s and all i did was swap the stock ones from my truck into his and his into mine. didnt change nothing else, his truck turned out fine and mine had a slight faint whine in the rear. tell me how that works??? seemed like it did it all the time regardless of acceleration or deceleration. i moved the backlash a little and it did nothing for the noise. i pressed the pinion bearing off and it has a .030 shim under it. which i think is a stock shim.. im a pretty skilled mechanic and this is def not my first gear change but i was wondering if theres anyone thats done alot of gear swaps in the 10.5s to tell me which shim i need. i know it comes down to checkin pinion depth and the pattern. but i also know that theres almost always a certain pinion shim you end up with. but i dont have a pinion depth gauge for this style rear and and i cant seem to get a good pattern no matter what i do??? so for those of you that have done 4.30s in a 10.5 let me know what pinion shim you used. so here i am.. lost.. can anyone help or guide me in the right direction?

did you swap your original pinion shim to the used gear?most times the original shim works.what does the pattern look like?what backlash did you have?too tight will whine and overheat the gear.sometimes a bearing will cause the same issue also.

well i never took the bearing off at first. i got it off now though to change it if i have to. but i originally just left the shim and bearing from his truck and put into mine. never messed with the shim. it was a .030 shim. not sure what stock is cuz i did the same with my gears and put in his truck and it was fine.. backlash was around .008 when i pulled them out of his and i tried opening it up to around .013 and didnt make a difference. the pattern is very hard to read for some reason. its consistant though

You can't just blindly change gears without doing the proper setup. Every gear set requires a different amount of pinion shim and carrier shims to get set up correctly. You are begging for a failure if you don't have someone set them up that knows what they're doing. When I changed my gears, I pulled them out and changed shims 5 times after checking the gear mesh patterns each time until they were correct.

Also, the pinion shim is as much to account for case differences as pinion differences, so using the shim from his truck is NOT the way to go. Good luck sorting things out.