An apparatus and method for producing pressure signals which indicate when weight-on-bit, during the drilling of a wellbore, exceed a predetermined, upper limit. The apparatus includes a first mandrel and a second mandrel that inserts into and is axially moveable within the first mandrel. The position of the second mandrel may be dependent upon the balance of a biasing member's biasing strength and the weight-on-bit exerted on the drill bit. If weight-on-bit values overcome the biasing strength of the biasing member, the second mandrel may move uphole within the first mandrel and create a pressure signal that is detectable at surface so that the operator is made aware that weight-on-bit values exceed the upper limit.