SUV Rocks


#1

A few months ago it only Rocked on the Highway when traveling at about 70 mph. I didn’t worry about it as the speed limits in my home town were 55 or less.

Then weeks later, It Started Rocking at 50, 45 , sometimes now even at 30! I can get it to stop rocking at any time by taking my foot off gas . But if I dont, the rocking gets worse and more pronounced. I really have to take the foot off the gas to keep driving. The cars behind me get a kick out of watching me rock! Now its almost impossible to drive on an interstate where limit is 70 or so…

I gotta get this fixed but I cant just keep buying new replacement parts until something works. Have you seen this?

No tunes, No shimmy in the steering wheel as someone suggested. New set of tires. Inflated perfectly… as another worried about. I’ve heard it was definately this or definately that and nether did anygood , only set me back overt a $1000 !



The Rocking is as if the whole frame sways to the left and then right. My left shoulder drops and then raises back up. No limp. its the car… OK thats the motion. Shocks ok and springs ok

2001 Infinity QX4 80,000 miles



help


#2

So all you’ve had done is new tires. Right off the bat, I would be looking for a broken spring, broken spring perch, bent or broken shock or shock mount, things of that nature.


#3
First check all four shocks/stuts.

#4

Check the engine and tranny mounts too.


#5

I agree with the possibility of engine mounts being broken, as the car rocks from side to side when you are accelerating or cruising steadily. It is as if something heavy is moving side to side. You could have a worn tie rod end to. Both struts damaged on one side? There are lots of things you could check without knowing where to start.


#6

The stabilizer bar (also known as “sway bar” or “anti-sway bar”) is supposed to stop “body roll”. Yours isn’t doing its job. Either the stabiizer bar or the stabilizer bar links are broken.


#7

I agree with JayWB.

This is the exact same symptom that a friend’s Explorer exhibited when he had a broken stabilizer bar link. IIRC, the Nissan Pathfinder is prone to breakage of this part, and your Infiniti is, after all, a Pathfinder. Have those stabilizer bar links checked and I believe that you will find the problem.


#8

Just to clarify…at 50mph what’s the cycle of this swaying motion ?

once per second ? once per minute ?


#9

Thanks for replies.

re: for more info questions.

Started with tire replacement, balancing, and then alignment
The rear shocks were replaced.
The front has struts , I believe and was told they were ok
The other question…
—At 50 mph , the cycle frequency is closer to 1 full sway left and right within 4 seconds.
And then it quickly gets more exaggerated and quicker but I never last more than a few seconds before letting off the gas

The comment below was right on , “It is as if something heavy is moving side to side.”
And the motion seems more exagerated coming from the front end

Even though rest of body is in great shape and I’m in the Carolinas where cars hold up, I’m afraid he may be right abut mounts but I’m disabled (spinal injury) and need to have garage check it out.

I never had them checked a stabilizer bar
I dont visit this board much but I knew I could get good input.

I am traveling next few days in another vehicle but taking this SUV in next week .
I just wanted to get an idea of things that could be wrong before I go into a garage…


#10

VDCdriver

I’ll start with
Nissan Pathfinder stabilizer Bar. I’ve seen this problem now on the web , thanks


#11

I’d look for something more fundamental as the root cause of this such as a bent wheel.

Even a small distortion will be amplified through any bad ball joints, stablizers etc but a bad ball joint wouldn’t be the origination of such a swaying motion, in fact distorted wheels would cause these parts to wear faster and may be the reason they are worn.

Another candidate is the traction control system, I think your truck has fancy trac system, if the were faulty it could cause these problems if it’s throwing traction diagonally as you drive, I’d get the sensors checked while it’s in the shop.