2000 Gmc Jimmy 4x4. Non-Zr2, GU6 (3.42) Gears, no G80 locker

For a while now ive had a "hum" from the rear axle when under load. Like simply from maintaining speed. I let off the gas it goes away. A while back i replaced the "spider gears" because i had alot of play in them (clunk when shifting from reverse to drive and vise versa) and they were worn, after i replaced them the clunk whent away. Now i dont recall the 'Hum" being there right after i changed them so ive been assuming my pinion bearing are going. But im wondering if the backlash has to be adjusted if all im changing is these gears. Or does the backlash only need to be adjusted if changing the ring and pinion? I didnt remove the carrier to do it. I used this. PowerTorque® 741A717A - Nest Kit | O'Reilly Auto Parts