Chassis Torsion
Chassis torsion is the twisting strain that arises in the body when one corner of the vehicle rises relative to the others about its long axis. It occurs when the four legs carry unequal loads. Its signs are doors and windows sticking, locks not catching and creaking in the interior panels.
An RV body behaves like a closed box, but it is not infinitely rigid against torsion. When one corner is raised and the opposite corner unloaded, the body rotates somewhat about its own axis. Door and window frames are the most sensitive indicators showing this rotation directly.
- Common causes: over-extending a single leg, one leg sinking into the ground, ground of differing hardness under the legs.
- Process: torsion may not cause instant damage, but as it is repeated the bonded joints and seals fatigue; water ingress starts this way.
- Check: open and close a door after the levelling has finished; if it closes with difficulty, the load distribution is uneven.
The right approach is to make the correction not with a single leg but spread across four legs. If the ground slope is large, do a coarse correction with ramps first, then run the system. Using a wide base plate under the legs also prevents one leg sinking during the day and creating torsion.
The context in which this term is used: RV automatic levelling guide