GM 15529450
Motor Mount

Starting the Engine Mount replacement requires users to disconnect the battery negative cable from the battery. The Engine Mount replacement requires supporting the engine in a proper manner that excludes jacking under the Oil Pan or sheet metal or Crankshaft Pulley because damage to the oil pickup unit may occur. You should jack up the engine while using a suitable lifting tool that avoids pressure on the mount systems. You should first remove the Engine Mount through bolt along with its nut before increasing engine elevation so you can remove the Engine Mount. In the 2 wheel drive model truck you must remove Engine Mount assembly bolts, nuts, washers before taking out the Engine Mount assembly itself. Passenger trucks with four-wheel drive require users to perform this procedure exactly as explained for the Engine Mount assembly installation. The installation of the Engine Mount assembly should be performed by putting it in place for both 2 wheel and 4 wheel drive models. Use the appropriate hardware to install the Engine Mount assembly including bolts, nuts and washers before tightening the bolts to 59 nm (44 ft. Lbs.) while the nuts require 45 nm (33 ft. Lbs.). Insert and tighten the Engine Mount through bolt after you lower the engine so that installation becomes possible. Then place the through bolt and the nut in position before tightening the through bolt nut to 68 nm (50 ft. Lbs.). The procedure ends with reconnecting the battery negative cable.

Before replacing the engine mount, first make sure the engine is well supported by a jack that doesn't place any weight on the mount. Raise the engine just a little so that removing the engine mount won't make the distributor contact the dash panel. If you are replacing just the front mounting, take off both because straining one can lead to additional stress. Unscrew and remove the through-bolt and nut from the engine mounting, then take out all the bolts, nuts and washers for the mounting assembly and lastly remove the mounting assembly. Position the mounting assembly in place, fasten it with the bolts, nuts and washers and tighten the bolts to 59 Nm (44 ft. lbs.) and the nuts to 45 Nm (33 ft. lbs.). After that, insert the through-bolt and nut for the engine mount and slid the engine down until the bolt is lined up to the hole. Then tighten the nut to 68 Nm (50 ft. lbs.).

The Engine Mount's examination should look for possible damage because damaged conditions may cause drive train component misalignment which puts excessive stress on working engine mounts when any mount fails. A screw jack should be used to lift the engine but placing a jack under the Oil Pan, sheet metal or Crankshaft Pulley should be avoided to prevent damage to the oil pickup unit from Oil Pan contact with the oil pump screen. Climb the engine up first to drain weight from the mount while implementing light pressure on the rubber cushion for mount inspection. The rubber and metal components of the mount need replacement if any heat check cracks appear on the rubber surface or if rubber separation from metal occurs or if a split damages the rubber. The mount should be secured by lowering the engine to allow proper tightening of bolts or nuts that anchor to the engine frame or bracket. Check the transmission mount using pressure on the transmission extension housing both upward and downward to determine whether the replacement is necessary if rubber material breaks its connection to metal or if the structure reaches its full range of movement. The bolt tightening procedure prescribed by fastener tightening specifications (Tightening Specifications) should be followed for all loose mounts.

It could damage the oil pickup unit.