Engine mounts seldom require attention, but broken or deteriorated mounts should be replaced immediately to prevent damage to driveline components. During the check, the engine must be raised slightly to remove the weight from the mounts. To do this, raise the vehicle and support it securely on jackstands, then position a jack under the engine oil pan with a large block of wood between the jack head and the oil pan, carefully raising the engine just enough to relieve the weight from the mounts without using the jack to support the entire weight of the engine. Inspect the mounts for any cracks, hardened rubber, or separation from the metal plates, as rubber can sometimes split down the center. Applying rubber preservative or W0-40 can help slow deterioration. Check for any relative movement between the mount plates and the engine or frame using a large screwdriver or prybar; if movement is noted, check the tightness of the mount fasteners before condemning the mounts, as broken mounts typically allow the engine to move easily when pried or under load. To replace the mounts, disconnect the cable from the negative terminal of the battery, then raise the vehicle and support it securely on jackstands. In the engine compartment, remove the engine mount-to-frame bracket bolts, which consist of three bolts on each side securing the mounts to the frame bracket. Attach an engine hoist to the top of the engine for lifting, avoiding the use of a jack under the oil pan to prevent damage to the oil pump pick-up. If a hoist is unavailable, casting lugs on each side of the engine block can be used to support the engine's weight during mount replacement. Raise the engine slightly until the engine mount can be unbolted from the block, then remove it from the vehicle. Installation is the reverse of removal, using non-hardening thread-locking compound on the mount bolts and ensuring they are tightened to the specified torque.