In this brief article, we are going to discuss the different GMC Envoy Rear Suspension problems, what the causes are, and Troubleshooting Tips.
Most common rear suspension issues in the GMC Envoy?
The most common rear suspension issues seen in the GMC Envoy are:
- Clunking Noise in the Front End
- Front Shock Absorber Strut Failure
- Rear Shock Absorber Failure
- Front Control Arm Failure
- Front Wheel Bearing Failure
- Rear Trailing Arm Failure
What suspension does the GMC Envoy have?
The GMC Envoy was first launched as a Mid-size SUV produced from 1998 to 2009 model years. The Envoy was basically the rebranded version of the Chevrolet TrailBlazer, Oldsmobile Bravada, Buick Rainier, Isuzu Ascender, and Saab 9-7X.
The GMC Envoy has a 5-Link live-axle rear suspension with a Coil Spring or a load-leveling air suspension, Shock absorber and an anti-roll bar.
Clunking Noise from Rear End
- ‘Clunking’ noise during normal driving especially on bad and rough road patches that cause the vehicle to “Roll” more.
- The same ‘Clunk’ noise reduces on smoother roads
Troubleshooting Clunking Noise from Rear End
- For most car suspensions, a ‘Clunk’ Noise is more related to the Anti-roll Bar assembly of the suspension
- The two most probable causes are:
- Anti roll bar Subframe mounting bush failure
- Anti roll Bar End-link Ball-joint failure
Anti roll bar Subframe mounting bush failure
- The Anti-Roll bar (ARB) bushings are the isolators between the ARB and the vehicle’s chassis. The bushings also ‘secure’ the ARB in place and restrict excessive movement so that the ARB can properly function.
- The ARB-to-chassis bushing is a D-shaped Rubber part that is secured by a C-Clamp both in the Front as well as the rear of the Grand Cherokee (WK and WK2 generations)
- The ARB is under torsional loads while the car is undergoing “Roll” motion either during cornering or Rough Roads.
- In these situations, when the ARB undergoes torsion, the mounting bushes also share part of the road loads.
- Bushings that have aged, hardened, or simply worn out and become loose tend to cause noise as they allow unnecessary movement of the ARB.
- You can easily check for Anti roll bar bush failure using a pry bar. Wedge it between the ARB and the subframe and try to lift the ARB. If it moves without much resistance and also creates a knock sound, then it means that the ARB bush needs to be changed.
- While refitting the Antiroll bar subframe bushing use a good anti-seize paste at the contact surface between the anti roll bar and the rubber bushing
- Anti-Seize application could be repeated periodically in order to prevent excessive wear, say, every 50K miles or so.
- For improving handling, you could search in the aftermarket for the same bushing with harder material. The harness is generally denoted by the Shore ‘A’ hardness number.
Anti-roll bar End link Ball-Joint Failure
- The ARB-to-suspension connection is done using ARB end links.
- On the front axle, the end links use a sealed ball joint design that has a significant range of motion sufficient for the various movements of the front suspension.
- The rubber boot that protects the end link Ball-joints can tear, allowing the joint lubrication to seep out and exposing the ball joint to corrosion. The result is a clunking noise from the worn joint.
- If the end links’ mounting fasteners have loosened on either end, it could result in clunking noise.
- On the rear suspension ARB end links, rubber bushings are used instead of ball joints. These end link bushings can age and then start to squeak.
- Use of Lubricants injected into the ball-joint by inserting a needle through the rubber boot could temporarily solve the squeaking sound problem. But it is always recommended that new end links be fitted.
- When changing the Anti Roll Bar End Links (also called Drop Links), Jack up both sides of the car.
- If you jack only one side at a time, there will be a twist in the anti-roll bar because of which you would find it difficult to align the anti-roll bar and end link at the bolt hole.
- Aftermarket End-Links with Greasable Ball-joints can be considered as an alternative. These would offer an extended life as compared to the OE sealed type of ball-joints, as they are serviceable.
- When inspecting for suspension noises and anti-roll bars, always jack the chassis/body and let the wheels hang
- When jacking up only one side, the anti roll bar applies downward pressure on both side wheels and it becomes difficult to check joints because they become extra tight.
Rear Shock Absorber Failure
- Knocking and Popping Noises from the Rear going over bumps
- Rear end feels bouncier
- Explained as seen on the WK generation (2005-2010) GMC Envoy
Troubleshooting Rear Shock Failure
- The Bouncy Ride symptom points to the Shock Absorber as a probable cause.
- The noises coming from the rear are partly due to the failed shock absorber allowing the bump stops to contact more often. And also the noises partly come from the worn out shock mounting bushes that allow the shock to move and hit against the mounting brackets.
- If your vehicle has crossed 40-50K miles, then it could be due for a shock absorber replacement. Due to long-term internal wear, the shock absorber starts losing its damping action over time.
- If the rear shock has started leaking oil due to a failed oil-seal, then it means that the shock will no longer be effective.
- One good way to tell if your shock has failed or not is to do a “Bounce Test”. Put all your weight on one of the front corners of the vehicle pushing it downwards. Keep oscillating the corner till you feel that it has reached its maximum height. Once you take your hands off the corner, observe how it settles. If it takes more than 2 oscillations to settle, that means the damper has failed.
- Once the Strut Shock absorber has been dismantled, there is one more way to see the shock condition for yourself by way of a ‘Compression’ test.
- You can simply apply force on the top of the shock and compress it. If it can come back up on its own, then the shock is in fairly good condition. But if it takes too long or doesn’t expand on its own, it’s confirmed that the shock absorber has failed.
- The Top mounting Bolts in the Rear Shocks of the GMC Envoy are located on the chassis side-rail
- It is always recommended to either loosen or tighten the Lower mounting bolts of the rear shock absorber only when the rear axle has been supported either using a Hydraulic jack or a jack-stand.
- As per the Shock absorber manufacturer, a new shock absorber must always be ‘Started’ before it is fitted. To ‘Start’ a shock absorber, you must oscillate it 3-5 times by hand.
- The reason for doing this is that when the shock absorber was stored lying down, in the fully compressed or expanded condition, the hydraulic fluid may not have flowed completely to one side of the piston. When this happens, the shock absorber will jerk during operation. ‘Starting’ will help to avoid this sort of jerky operation.
- While fitting a new shock absorber, always, Tighten the Top mounting bolts first and then the Lower mounting bolt.
Rear Wheel Bearing Failure
- Droning noise above 30 mph speeds
- Sound is louder with increasing speed
Troubleshooting Rear Wheel Bearing Failure
- Droning noise is generally associated with one of the wheel bearings depending on where the noise is coming from
- Wheel bearings generally have a life of 70K miles, after which, on detecting noise issues, must be replaced
- In the GMC Envoy, the wheel bearing is housed within the Knuckle and the Wheel Spindle. It is of a single-piece design.
- The Wheel Hub assembly comes as a unit along with the Wheel bearing press-fitted
- In order to remove the wheel hub assembly you may need to use a 3-leg Gear Puller
- Make sure to properly route the ABS sensor wire while mounting the Wheel hub assembly
Rear Trailing Arm Failure
- Rear Tire uneven wear; Cupping
- Handling is poor; Rear end rolls more in lane changing
- Knocking noises while driving over normal roads
Troubleshooting Rear Trailing Arm failure
- The rear trailing arm takes up part of the rolling resistance of the SUV, in effect, assisting the springs and Anti-roll bars
- Failed or deteriorated rubber in the trailing arm bushes will result in lower roll resistance of the SUV and lead to poor handling
- The GMC Envoy rear trailing arm is also susceptible to rust
over time and even breakage when fully corroded
In this brief article we have discussed the different GMC Envoy Rear Suspension problems, what the causes are, and Troubleshooting Tips.
For any questions or comments, please feel free to get in touch with us.