What cause a truck to rock side to side when driving?
Does the vehicle rock faster at higher speeds, or is it a constant no matter how fast you're going? Is it a gentle rock, or does it seem like more of a shake at higher speeds? Does your vehicle have hydraulic shocks, air shocks or regular shocks and springs?
If your vehicle is rocking at low speeds and the rock turns into a shake or vibration at higher speeds, you might have a bent axle. For this problem to be bad enough to fees as a rocking motion at low speeds you should probably be able to tell by looking at your wheels -- if your axle is bent, you should see that one of the wheels seems tilted slightly. If you move your car a few feet and look again, it should look like it is tilted in a different direction. If this is the case, have the axle replaced ASAP to avoid more damage to your suspension system.
If the rocking does not change at any speed, then you have to consider your suspension system. If you have a hydraulic or air suspension on your vehicle, it might be malfunctioning. If you have air shocks, one of the air bags that holds your vehicle in the correct position could have a slow leak -- this could cause that part of the suspension to float down as it loses pressure and back up as the pump adds more air -- which would feel like a slow rock inside the car. The same could happen with a leaking hydraulic. If this is the case, bring the vehicle in to a mechanic and have your suspension checked ASAP to avoid causing more damage to the system.
If neither of these is the case your wheels might be out of alignment. This would also cause a funny, cyclical noise from your tires as you drive and should be taken care of ASAP as it will cause extreme wear on your tires. If this is the case, your tires will probably already show uneven wear on the tread (if the inside of the tread (near the center of the car) is worn out more than the outside of the tread then this could indicate a bad alignment).
If your tires are not worn funny, and nothing else here has helped, you might have bad tie rod ends, ball joints or loose lug nuts on one of your wheels. First, make sure the lug nuts on each tire are properly tightened -- if there were loose nuts you might have fixed it. If all of the nuts are tight, jack up your front end so your tires (one at a time) is about an inch off the ground. Grab the top and bottom of the tire and try to rock the wheel -- if the top and bottom of the wheel move towards the center of the car, you probably have bad ball joints and you should have these replaced IMMEDIATELY (they are a vital part of your steering system and need to be in good shape for safe driving). If the wheel does not rock up and down, try grabbing the tire on the front and back and see if it rocks (if you have only 1 tire off the ground there should be no play ... if both front tires are in the air then pay attention to the tire on the other side of the car as you do this or have someone hold the steering wheel). If the tire moves, without turning the steering system of the car (the other tire doesn't move with it) then it's likely to be your tie rods or tie-rod ends. These are also a vital part of the steering system of your vehicle and should be replaced IMMEDIATELY to ensure safe driving.
If none of these are the problem. take the vehicle to a mechanic and tell him what you have done to check the vehicle (this can save time by helping the mechanic eliminate possible causes).
Jun 01, 2011 |
2003 Nissan Pathfinder