Q: Can control arm replacement cause axle to break?

If care for the surrounding components is not taken during the service, a tool can slip and cause damage to the cv axle boot and cause the boot to leak grease while driving, but it would take a lot of effort to damage the axle to the point where the shaft or the joints are broken. Consider hiring an experienced technician like one from YourMechanic who can come out and inspect the area to offer a more personal diagnosis on the problem with your cv axle.

When replacing the control arm it would not damage the axle under normal installation. Without knowing the axle failure cause it would not be able to be determined by the information given. Axle joints can fail if the boot that covers the joint gets damaged during the work being done and can cause joint premature failure due to loss of lubrication to the joint and dirt and debris will get into the joint and damage it.