Adjusting torsion bars

I always jack my car up with wheels off the ground while adjusting.
It seems to put alot of tension on the bolt threads with the car on the ground, almost feels like they are stripping out.

I have tried to jounce the car to get it to settle after adjusting only to find that after a test drive, the measurements were different, so I always test drive and readjust as necessary as someone else mentioned above.