Jacking to change a tire or service brakes or bearings?

We carry 8-2x10x18" (screwed together) for leveling and if need to change a tire, would just place them in front of or behind bad tire under the frame and center bottle jack on I-beam and jack away. When I grease the wet bolts, 4er is hooked up to truck and I just place jack under frame in front of front tire. This ironically will lift whole side I'm doing. So grease the bolts, then 3-4 shots into end of axle while spinning the tire. Repeat for other side.