How to Change Motor Mounts on a 1999 Chevey Tahoe

The 1999 Chevy Tahoe base model came with a 5.7-liter eight-cylinder engine and a four-speed automatic transmission. The engine in your Tahoe has two mounts, one on each side of the engine, that secure the engine to the frame. Over time the rubber bushings in the motor mounts can become worn causing excessive engine movement during idle and heavy engine load. Replacing either motor mount will require the engine be lifted enough to unbolt and remove the assemblies from between the engine and frame rails.

Instructions

Park the vehicle on a level surface and set the parking brake. Lift the vehicle hood and support it with the hood prop rod. Examine the engine wiring harness and locate any harness-to-engine connections that will be strained or pulled if the engine is raised. Mark the wiring harness and connector with a permanent marker and masking tape, then disconnect the harness from each component; pay special attention to the plugs on the top of the intake manifold, as they are often the shortest.

Lift the front of the vehicle into the air with a floor jack and place jack stands under the front frame rails. Lower the vehicle until it rests securely on the jack stands. Position yourself under the vehicle and look towards the front of the engine to find where the engine mounts to the front frame rails. Hold the engine mount through-bolt stationary with a wrench and remove the nut with a socket and ratchet on both front mounts.

Place a block of wood on the floor jack arm and lift the jack until it contacts the engine oil pan. Slowly lift the engine to separate the engine-side and frame-side portions of the mount; check the engine wiring harness plugs with every pump, mark and disconnect any plugs that may become strained. Continue to lift the engine until there is enough clearance to remove the inner mounting bolts.

Remove the engine mount to frame bolts with a socket and ratchet. Remove the frame side mount assembly from the vehicle. Remove the engine mount to engine block bolts with a socket and ratchet. Remove the engine-side mount assembly from the vehicle. Repeat this step for the opposite mount, if necessary.

Clean the mounting bolts with a wire brush and inspect the bolt threads. Replace any worn or damaged bolt as necessary.

Position the new engine side mount assembly into place and install the mounting bolts. Tighten the engine side mounting bolts to 44 foot-pounds with a torque wrench. Position the frame side mount into place and install the mounting bolts and nuts. Tighten the bolts to 44 foot-pounds and the nuts to 33 foot-pounds. Repeat this step for the opposite side, if necessary.

Slowly lower the engine until the mounts joint and the through bolt can be inserted. Push the through bolts into each engine mount and install the through bolt nut. Tighten the through bolt and nut to 50 foot-pounds with a torque wrench. Remove the floor jack and block of wood.

Lift the front of the vehicle off the jack stands and remove the jack stands from under the vehicle. Lower the vehicle to the ground. Remove any masking tape and connect any disconnected wiring harness connectors one by one. Shut the vehicle hood.