[jagcoq]

I have a 2007 QX56 and am looking for some solutions to the poor handling characteristics of the rear air shock and suspension. When driving on highway and I encounter grooved pavement, the rear end sways and will cause loss of control and excessive movement over bumps. On snow/ice pack, occasionally cause complete loss of contact.

On normal driving, hitting bumps in a turn, often causes the rear end to "jump". I notice that the suspension does not do a good job of "damping", instead, magnifies the motion. Especially side way motion, or "yaw".

Does anyone have suggestions for rear suspension modifications that would improve handling and reduce body roll and sway? I have changed the front shocks out with good coilovers and that has helped--the local 4x4 shop is recommending custom spring coils from Deaver to stiffen the rear end (I also tow 8000 lb rv.).

Finally, the air shocks will not hold the normal 750lb tongue weight below 30 degrees F....the dealer says nothing wrong, but in summer, I have no problems.

Thanks for any advice.

 

[Pops]

That's exactly how it acts when it's out of alignment. Most alignment techs are incapable or too lazyto align the rear on these properly.

Take it in to an alignment shop who knows what they're doing then post the final printout on here.

Alot of techs won't worry about it as long as the numbers are all in the green and that's not always good enough... We need the Toe specs down to as close to the lowest allowed number as possible and the camber needs to be pretty straight too or flexing will throw the Toe off while driving on the road.

 

[jagcoq]

Thanks for the quick information, I'll get right on that alignment! Should I look into bigger sway bars to help as well? Do you have any ideas on why the cold weather would affect the air shocks?

 

[BlakSpyda]

Welcome jagcoq!

 

[Pops]

Don't change the sway bars, anything stronger will make the ride harsher. Cold weather doesn't affect tham as bad as your description.

 

[jagcoq]

Alignment

POPs--
you were spot on with the alignment suggestion. Front was fine...rear was out.

Before:
Camber--
RL B4 -1.2 After -.8
RR B4 -1.6 After -.9

TOE--
RL B4 .27 After .04
RR B4 .23 After .04

Make a huge difference--do you think they got it, or should I get even better? Now on to the tires I guess!

Thanks so much for your help. The Dealer did not catch this...

 

[Pops]

If the ride is good like you want it and your MPG is the same or better, then that should be fine. IMHO, you should mention it to the dealer sometime, it's one of those live and learn things that most Service Techs wouldn't think of.

 

[WaynesNside]

I notice mine does that too on bumps at a good speed. I thought that was just the drive style of the vehicle.

I'm going to look into alignment also.

 

[4Mogger]

I also noticed a big improvement after an alignment last week... But I am unsure how much of the improvement is due to the new Nittos.
Now I wish I had the before/after numbers for the alignment.

 

[jagcoq]

I have also added Firestone Coil Rite bags to rear springs last week. Another huge improvement to handling and sway. With the SAW's on the front, near perfect alignment and the bags, I have solved almost all my issues....thanks again to POPS for pointing me in the right direction.

 

[gbertsch01]

I have the coil rites as well, they work real good. I just put on new terra grapplers and had the wheels aligned, turned out they were way out of spec, think it's a must do every year or so.

 

[time4akshun]

Experience same thing when I changed to bigger wheels. Bilsteins in front helped but rear alignment was key. Was way off!! An additional problem I had was seized bolts on control arm. Needed to replace rear arms.

 

[DavidNJ]

Did the you guys connect the Firestone Coil Rites to the stock load leveling pump/sensors?

If that works it should be possible to put some serious shocks in the rear.

 

[Investments18]

2008 Infinity QX56 has steering & suspension problems

The 2008 Infinity QX56 has suspension and steering flaws that are very dangerous and may lead to a crash. Car drives and handles fine but over any road imperfection the steering wheel shimmies and shakes and feels like you are about to lose control. Steering wheel must be held by two hands and even then feels like rear end is jumping and about to separate from front end. I replaced shocks and various other suspension items and had an alignment but there's something wrong with the way this car handles. Also feels like steering column is about to break off the vehicle. I updated and replaced all sway bar links, tie rods, control arms, steering bushings and other suspension bushings and nothing is helping address the unsteady feel of steering. If I will not hold steering wheel tight with both hands, I will lose control. After spending $4 thousand on updating all suspension components I'm getting rid of my car because I feel its unsafe.

 

[drewcs]

The 2008 Infinity QX56 has suspension and steering flaws that are very dangerous and may lead to a crash. Car drives and handles fine but over any road imperfection the steering wheel shimmies and shakes and feels like you are about to lose control. Steering wheel must be held by two hands and even then feels like rear end is jumping and about to separate from front end. I replaced shocks and various other suspension items and had an alignment but there's something wrong with the way this car handles. Also feels like steering column is about to break off the vehicle. I updated and replaced all sway bar links, tie rods, control arms, steering bushings and other suspension bushings and nothing is helping address the unsteady feel of steering. If I will not hold steering wheel tight with both hands, I will lose control. After spending $4 thousand on updating all suspension components I'm getting rid of my car because I feel its unsafe.

Sorry to hear that. Looks like you replaced everything but did you do the front shocks? Replacing the shocks with Bilstein HD's or 5100's would have probably solved your problem.

 

[Investments18]

2008 Infinity QX56 has suspension and steering flaws

Yes I replaced all 4 shocks with new factory ones. Reading other posts it clearly appears that the QX56 is poorly designed and the steering and suspension are not capable of supporting the weight of the vehicle. Yes I replaced tires with all new Continental all season and sway bar links, control arm, tie rods and though the fish tailing improved, the steering still "jumps" to the right over man hole covers or other road imperfections. After owning this car for few months, sadly I'm selling it and do not recommend this model to anyone, despite the fact that I love its size, options and the roomy interior. To put it mildly, the Infinity QX56 is a horrible poorly designed and unsafe car. I shouldn't have to feel like the back end of the car and the front end are two seperate vehicles improperly welded together and thus the fish tailing and rear jumping issue.

 

[drewcs]

That's too bad. The Bilsteins over the factory shocks would have made all the difference.
Good luck with your next vehicle.

 

[blackArmada_Dxb]

The Bilsteins will improve the ride, but it won't satisfy a perfectionist like him. I am happy with my ride now, but that's because I went aftermarket on all my suspension components. I still believe there is some room for improvement in the rear, but I am 100% certain that stiffer rear springs will solve my issue. Just waiting to hear from Greg on approximate production ready dates. My front doesn't bounce around at all. New stiffer rear springs and Timbren bump stops will make my car ride better than new. I know that. For the OP, I guess he will need to buy a Cadillac or something purely American. If he opts to go with a Sequoia or Land Cruiser or even a Lexus,it won't make a big difference because they just ride just as good or bad as the Armada. Just my 2 cents.


Sent from AutoGuide.com Free App

 

[Pops]

Most of it depends on local shops. Sounds like whoever Investments18 had working on it didn't know what they were doing even if it was a dealership. At $4k that thing should've been driving better than a Cadillac, sounds like there's some shady shops in that area.

 

[blackArmada_Dxb]

Yeah, I agree. $4k is a lot of money! Phew!