GM 89038654
Shock Absorber

First step to replace a shock absorber begins with raising the automobile while keeping it secured. The shock absorber replacement process begins by unscrewing and removing the upper shock absorber nut and bolt before moving onto the lower shock absorber nut and bolt until the shock absorber can be extracted. After installation placement must be achieved by positioning the new shock absorber followed by setting it in place with the upper shock absorber nut and bolt. Secure the lower shock absorber by applying the nut and bolt and tighten both nuts to reach 95 Nm (70 ft. lbs.). Finish the procedure by lowering the vehicle after removing safety stands.

The vehicle needs to be raised through a lift then supported before starting the Shock Absorber replacement process by installing jack stands below the lower Control Arm. The technician should first disconnect the (RTD) link rod from the sensor device and remove the electrical connector if the vehicle has selectable ride. Rephrase the following sentence. Also normalize verbalization when possible. The connector lock tabs (1, 2) should be rotated counterclockwise to unlock the connector, which can be disengaged by pulling upwards. Have a wrench ready to hold the tennon end while removing the nut before taking out the upper insulator except for the plastic pilot ring. Disassemble the Shock Absorber mounting bolt at the lower Control Arm for 15 series and 25/35 series vehicles and the Shock Absorber can be extracted. Before mounting the Shock Absorber stem must pass through the shock bracket opening on the frame until it lines up with both lower Control Arm holes from both series. Mount the Shock Absorber by passing it through the lower Control Arm bolt which leads to the bolt nut then complete tightening this nut to 80 nm (59 ft. Lbs.). The upper insulator needs to go on top of the shock mounting bracket on the frame with the plastic pilot ring used to align it properly. The Shock Absorber receives the upper insulator followed by attaching the nut to the tennon end without tightening it. Connect the rtd link rod to the sensor if it exists and then take away safety stands before lowering the vehicle. A wrench should be applied to the tennon end while tightening the nut to 20 nm (15 ft. Lbs.). Verify selectable ride equipment has an unlocked connector before aligning the tabs perpendicular to the wrench flats on the tennon end and engaging by firm downward pressure. Rotate the lock tabs (1, 2) counterclockwise until they snap into place along with an audible noise while maintaining their perpendicular alignment with the wrench flats on the tennon end. Finally, dispose of the Shock Absorber.

Breathing gas pressure inside shock absorbers presents a risk of dangerous explosive force so remove the snap ring from the tube top only if you have no need to eliminate this danger because it can cause severe personal injury. Wear protective safety glasses when piercing holes in the shock absorber while drilling while keeping the shock absorber tube safe from damage. Create a centered mark that measures 10 mm (0.4 inch) from the base of the tube through centerpunching. Secure the shock absorber to a vise position with its shock absorber rod in fully extended position. Use a 5 mm (3/16 inch) drill bit to make the hole at the centerpunch position and direct the escaping gas or gas/oil mixture while containing oil with shop towels. The next step requires creating a centerpunch indentation on the tube followed by drilling a 5 mm (3/16 inch) aperture at that point while using shop towels to collect the oil discharge. The shock absorber gets moved to a drain pan where you horizontally position it with the holes toward the floor. Then extend and retract the rod through the tube to drain all oil.

The snap ring inside of the gas charged shock absorber tube contains high pressure gas therefore avoid removing it since the contents could accidentally fire out with violent force resulting in injury. Safety glasses should be worn during shock absorber centerpunching and drilling while taking all necessary precautions to avoid damaging the shock absorber tube. You need to create a 10 mm (0.4 in) indentation starting from the bottom of the tube by using a centerpunch. Secure the shock absorber horizontally within a vise by extending its rod completely. Drill a hole at the centerpunch using a 5 mm (3/16 in) drill bit that will release gas and or mixture but oil needs to be collected using shop towels. The tube receives another 5 mm (3/16 in) drill hole between the center punch markings for oil to drain safely using shop towels for containment. You should hold the shock absorber vertically over a drain pan while placing its holes facing downward before performing rod movements to extract all the oil through the tube.

Gas charged shock absorbers need strict handling due to their high pressure gas content thus do not remove the snap ring from inside the tube top because it poses an extreme force risk of personal injury. Safety glasses must be worn when cutting with the center punch and drilling the shock absorber tube to avoid puncturing or harming the tube. Drive the centerpunch 10 mm (0.4 inch) down from the tube bottom to begin. Fix the shock absorber vertically within a vise where its rod is fully stretched. Drill a hole at the centerpunch using a 5 mm (3/16 inch) drill bit which should provide a gas or gas/oil mixture outlet point while using shop towels to collect the escaping oil. Move the centerpunch to drill another hole at the middle of the tube with a 5 mm (3/16 inch) bit to exhaust oil while employing shop towels for containment. After removing the shock absorber from the vise position place it horizontally above a drain pan so the holes face downward while moving the rod inside the tube to drain all the oil.

The replacement process of rear suspension shock absorbers in 25 Series vehicles starts by raising and securely supporting both vehicle and rear axle. Start by disconnecting the electronic suspension control (ESC) electrical connector through the pigtail at the left side only and via the right upper shock mount when the ESC sensor exists. Begin by removing the upper shock absorber nut and bolt and subsequently detach the lower shock absorber nut and bolt before extracting the shock absorber from its position. Install the new shock absorber by attaching the bolt to its upper position followed by tightening both nut connections to 95 Nm (70 ft. lbs.). The procedure continues by reinstalling both nut and bolt of the lower shock absorber before removing the rear axle support to connect the ESC sensor and electrical connectors according to their original arrangement. Finish the process by taking out safety stands then lower the vehicle.

Do not remove the snap ring from inside the top of the tube to avoid the risk of personal injury from the contents being expelled with extreme force.

Remove the support from the rear axle, take away the safety stands, and lower the vehicle.

Use a 5 mm (3/16 inch) drill bit.

Raise and support the vehicle.

Remove the shock absorber mounting bolts at the lower control arm and extract the shock absorber from below.