Jeep Tech Tip: Proper Torque Of Mounting Bolts

Jeep Tech Tip: Proper Torque Of Mounting Bolts

A frequent concern of technicians is that customers complain of rattling noises after the rear shocks have been replaced on 1999-2003 Jeep Grand Cherokee vehicles.

Models

1999-2003 Jeep Grand Cherokee

A frequent concern of technicians is that customers complain of rattling noises after the rear shocks have been replaced on 1999-’03 Jeep Grand Cherokee vehicles.

The noise originates from the shock mounts on the Jeep. The cause is lack of proper torque on the mounting bolts. Jeep recommends 80 ft/lbs of torque on the upper mounting bolt and 85 ft/lbs of torque on the lower mounting bolt.

• If the bolts are undertightened, they will eventually loosen and slip, making the noise. If this happens, the installer will usually retighten the bolts.
• It is easy to go beyond the recommended torque, however, and overtightening will cause the shock absorber’s steel sleeve material to crush. Once the sleeve is crushed, it cannot hold proper torque, thus causing a rattle.
• Shocks that have had their mounting bolts overtightened should be replaced.
• New shocks should be properly tightened with a torque wrench to the recommended specifications.
• Replace the mounting bolts if it is believed that they have been overtightened.

Another less frequent cause of shock mount rattle on this vehicle is the result of installing stock suspension shock absorbers on a vehicle that has a lift kit. The stock suspension shocks will frequently top (fully extend) during normal suspension movement because they are no longer the correct length for the vehicle. Topping puts extreme loads on the shock mounts, which they are not designed to receive, and the impacts will eventually damage the mounts and the shocks. This damage will result in noise. Measure the ride height of the vehicle, inspect the suspension and consult with the customer to determine if a lift kit has been installed. If so, install shock absorbers with the correct lengths to accommodate the lift kit.

Courtesy of Gabriel Ride Control

You May Also Like

Chassis Parts and Alignment Angles

Knowing why the adjustment is required is critical to performing the total alignment.

An alignment angle doesn’t change randomly. There is a cause-and-effect relationship between external and internal forces that can alter the geometry of a vehicle’s suspension. Having the alignment reading for only one angle on one corner is just like knowing the temperature without knowing if there is a tornado outside.

Suspension Upgrades – Selling Shocks and Struts

The question customers fail to ask is, what is “best” for their vehicle?

Air Ride Suspension Diagnostics

The key to understanding the logic of air ride systems is using service information.

Steering Angle Sensor Operations

It is important for the ABS/ESC module to receive two signals to verify the steering wheel’s position.

Chassis Alignment

The source of the complaint can be the angles, electronics or tires.

Other Posts

Mercedes 4MATIC Diagnostics

The Mercedes-Benz 4MATIC all-wheel drive (AWD) systems have been around for a while now.

Laying Out Your Shop for ADAS/EV Repairs

With so many vehicles equipped with some form of ADAS, rethinking your electronics layout or plan might be in order.

Broken Springs

What is the cause for the failure? Why does it occur with specific vehicles?

The Importance Of ADAS Calibrations

Following best practices and using appropriate equipment ensure customer satisfaction and safety.