A viscous spring damper including inner and outer members connected by an elastomeric shear spring and having a main or first fluid chamber disposed therebetween for communication with a second fluid chamber in the inner member through a restricted orifice. The inner and outer members are relatively movable for stressing the shear spring and varying the volumes of the chambers while fluid is transferred therebetween through the restricted orifice. An elastomeric bladder within the second fluid chamber is selectively chargeable with gas pressure for calibrating the damping characteristics, varying the initial spring rate or leveling a vehicle on which the damper is installed. An elastomeric diaphragm is included in the main fluid chamber for providing a selectively chargeable diaphragm gas chamber. Integrally formed wear ribs in the diaphragm minimize diaphragm abrasion effects at points of engagement between the diaphragm and the inner member and preclude an hydraulic lock between the diaphragm and the inner member.