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QuadraLift problem

9K views 36 replies 14 participants last post by  Mongo53 
#1 ·
In Normal ride height I have no problems. When I raise it to off road 1 that's where the problem begins. If I hit a speed bump in OR 1 I hear a loud bang. It's even worse in OR 2. Is seems to be when the bags are "rebounding" from the compression of the bump. Any suggestions as to what the problem may be? I understand that in those higher modes it will ride stiffer but it almost seems like it's bottoming out and it's an extremely loud bang.
 
#2 ·
It's typical. Most people who complain about it are driving in a raised position on the road, not off road. It happens because the higher the car is raised the less room it has to move going up.




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#3 ·
its not a problem its just a shit design and a great sales gimmick. in any other 4x4 with coils you still have suspension as such. with airbags the tighter they become they dont compress as easy and acrually ride stiffer. thats why in sport mode or over 60mph the ride is plush the air is let out of the bags and absorbs all bumps.
 
#7 ·
It's not a "problem"...as already noted, it's the nature of the suspension design. When you raise it up, you have very little travel left, especially at OR2 height. That's why it's limited in speed and will drop down when you exceed those limits to the next lower setting until you're back to "Normal". OR2 should only be used when you truly need that extra inch or so. OR1 is fine for many off-road situations and at off-road appropriate speeds. It wasn't designed for "street driving". Normal and Sport are setup for that.
 
#8 ·
As stated it is considered "normal ". I did the same thing you did. So excited to have my brand new fancy 4x4, on the way home from the dealership I raised it up, on my street and went over our speed bumps going less than 5 miles an hour. What the hell was that noise? Did they forget to install the shocks?
Called the dealer they had never heard of such a thing. Took it in and the service advisors jaw dropped when I took him for a ride. I then took their suspension guy for a ride. He said "yeah, that's the air shocks, they do that."
In a Chrysler survey I said that my concern wasn't handled. They wanted me to take it back but it would cost me $50.00 for diagnosing the issue if it wasn't considered warranty.
I gave up. Those who are telling us that it isn't an issue because it isn't supposed to be used when going over speed bumps and is only for off-road use clearly don't know that it is unacceptable at any time.
I've since taken it off road in fairly mild conditions. It clunks unbelievably.
I am extremely disappointed. I'm stuck with the jeep. It is very nice with the exception of the suspension design.
There is a comparison of the GC, Range Rover, Chevy Siverado and Ram 2500 in Off-road Magazines 4x4 of the year.(2014) They site the suspension problem as one of the cons for the jeep. They suggest that the Range Rover used to have the same problem but they figured out how to fix it and Jeep probably would too, in the future.
I wish I had read this review before I plunked down 45k for my first Jeep. My old dodge and my old Landcruiser sure don't clunk like my new fancy 4x4.
Hopefully Jeep will get the hint and come up with a fix.

P
 
#11 ·
ORII is designed for extreme conditions where you have to crawl over something. Most people, even those who go 'off roading' probably never need it. If you do need to use ORII, 5mph is probably too fast.

It is not designed for speed bumps at the mall. ;)

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#21 ·
ORII is designed for extreme conditions where you have to crawl over something. Most people, even those who go 'off roading' probably never need it. If you do need to use ORII, 5mph is probably too fast.

It is not designed for speed bumps at the mall. [emoji6]

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I hate the limitation. At the beach there’s always someone that put huge ruts down. ORII is good to get through them but the speed limit really hurts. Most my off-roading is at the beach hitting soft spots of powder like knee deep depth. Feel its a missed Jeep category.
 
#13 ·
I have posted on Jeep Forum concerning my Quadra Lift issues. It is a problem and should not be dismissed by telling people that they are driving incorrectly. Briefly my suspension makes a large 'kabamm' noise when going very slowly (2mph) over a sharp bump. The noise occurs both front or rear tires over bump. Test drove with Jeep service people; also tested similarly outfitted new cars on lot on same course. Service manager says noise on my car is 'scary' but each time consulting under Star Case the engineers say it is normal. Test drives demonstrate that my car is not normal. I am on second Star Case waiting on test drive with Jeep engineer. So far Jeep replaced damaged front air spring shocks and controller. Also I am told sway bar bushings are worn, I assume a symptom of the suspension problem too, but Jeep has not offered to pay for sway bar units. I keep saying the car is underpressurized since it lifts correctly (static load) but bounces under dynamic load.
 
#14 · (Edited)
Best I can tell, when you raise or lower the QL suspension, you're just changing air pressure, which is the same as spring rate. If the air pressure is more, the spring rate is more and the air bag/spring extends more for the same weight and the vehicle raises. If the air pressure is less, the spring rate is less and the air bag/spring compresses more for the same weight and the vehicle lowers.

I'm no lift kit expert, but I "think" most lift kits are springs that are longer with the same or less spring rate.

So correct me if I'm wrong, but I see nothing else in the suspension that changes. So just like when you put in blocks or shorter or longer springs, all you're doing is trading rebound for jounce or vice-a-versa.

I think the WK2 has 8.7" of front suspension travel and 10.2" rear travel. If you're suspension ride height is set at mid-point, that's 4.35" that it can move up (Jounce) and 4.35" it can move down (Rebound). Or 5.1" for the rear.

[EDIT]I just read the QL has 4.1" of total suspension travel, if that is true, I'd hate to say it, but it sounds like that is the cause of the problem, and IMO makes it a less capable system than the standard coil springs.

If you raise the suspension 2.6", that means the front has 6.95" of Jounce but only 1.75" of rebound. So when you hit that speed bump, you have 6.95" of space for the wheel to go up, the spring rate is greater, so it's going to resist that wheel going up more, once you get over the top of the speed bump, the suspension will start to rebound and come back down, and it will need to go a little farther than the original point, ride height, but you only have 1.75" for the wheels to extend down, with more spring rate pushing them down. They rebound more than 1.75", you're going to hit the upper bump stop.


Keep in mind, springs naturally bounce, if it is wasn't for efficiency lose through friction and heat, once a spring bounced, it would continue to bounce forever. It's the shock that damps that bounce and reduces it constantly decrease to be less and less, most cars it's one bounce, at least only one noticeable bounce. The damp rate has to match the spring rate to prevent bouncing. You inflate the airbags an increase air pressure, that raises the vehicle, but nothing changes in the shocks damping rate. So more spring rate with the same damping would result in bouncing. They could over damp the shocks, so that the damp rate matches the air bags at their highest spring rate. But it only take one good thunk of a shock to reduce its damp rate.

Am I wrong on that? Is there some sort of adjustable valving electrically powered in the shocks changing the damp rate as spring rate changes.

You could put the airbag under or over top of the spring, that would raise or lower the vehicle without changing spring rate. But it would require a lot more room to do it.
 
#15 ·
Best I can tell, when you raise or lower the QL suspension, you're just changing air pressure, which is the same as spring rate. If the air pressure is more, the spring rate is more and the air bag/spring extends more for the same weight and the vehicle raises. If the air pressure is less, the spring rate is less and the air bag/spring compresses more for the same weight and the vehicle lowers.

I'm no lift kit expert, but I "think" most lift kits are springs that are longer with the same or less spring rate.

So correct me if I'm wrong, but I see nothing else in the suspension that changes. So just like when you put in blocks or shorter or longer springs, all you're doing is trading rebound for jounce or vice-a-versa.

I think the WK2 has 8.7" of front suspension travel and 10.2" rear travel. If you're suspension ride height is set at mid-point, that's 4.35" that it can move up (Jounce) and 4.35" it can move down (Rebound). Or 5.1" for the rear.

If you raise the suspension 2.6", that means the front has 6.95" of Jounce but only 1.75" of rebound. So when you hit that speed bump, you have 6.95" of space for the wheel to go up, the spring rate is greater, so it's going to resist that wheel going up more, once you get over the top of the speed bump, the suspension will start to rebound and come back down, and it will need to go a little farther than the original point, ride height, but you only have 1.75" for the wheels to extend down, with more spring rate pushing them down. They rebound more than 1.75", you're going to hit the upper bump stop.


Keep in mind, springs naturally bounce, if it is wasn't for efficiency lose through friction and heat, once a spring bounced, it would continue to bounce forever. It's the shock that damps that bounce and reduces it constantly decrease to be less and less, most cars it's one bounce, at least only one noticeable bounce. The damp rate has to match the spring rate to prevent bouncing. You inflate the airbags an increase air pressure, that raises the vehicle, but nothing changes in the shocks damping rate. So more spring rate with the same damping would result in bouncing. They could over damp the shocks, so that the damp rate matches the air bags at their highest spring rate. But it only take one good thunk of a shock to reduce its damp rate.

Am I wrong on that? Is there some sort of adjustable valving electrically powered in the shocks changing the damp rate as spring rate changes.

You could put the airbag under or over top of the spring, that would raise or lower the vehicle without changing spring rate. But it would require a lot more room to do it.

There is a major difference between steel springs and air springs. Unless specifically designed to be variable rate, steel springs are linear. Air springs, esp ones operating at high pressures like the JGC, are non-linear.

This has a pretty good explanation..

Air Spring vs Coil Spring Characteristics- Mtbr.com

It would seem to me that changing from air to steel springs might well call for a differently calibrated shock absorber to deal with the change in linearity.
 
#19 ·
I posted a few days ago but cannot find my post. I get a large 'kabamm' noise in OR1. Tested two similarly equipped cars on lot accompanied by service advisor. He wrote up report that my car makes a loud noise, cars from lot do not. Test drove with service advisor; he said my car noise is 'scary'. Dealer calls Chrysler, engineers say it is normal. Guys, there are degrees of normal and we should not be dismissed. We were driving about 1-2 mph over a parking lot bump. I think the system is pressurized enough for a static load but not a dynamic load. It will lift. It lifts and stays lifted which tells me that there is a leak on the compressor side of the system. My theory is that at normal atmospheric pressure the car has enough gas for the compressor to pump through the one way valve to lift the car statically. This was confirmed when the first dealer had to reload nitrogen in the system. That dealer had to replace the damaged front spring shocks. My sway bar bushings also are shot but Chrysler will not replace. I was just out of warranty at 37k when the dealers finally started assessing. Two STAR reports later the engineers still claim normal.
 
#22 · (Edited)
I posted a few days ago but cannot find my post. I get a large 'kabamm' noise in OR1. Tested two similarly equipped cars on lot accompanied by service advisor. He wrote up report that my car makes a loud noise, cars from lot do not. Test drove with service advisor; he said my car noise is 'scary'. Dealer calls Chrysler, engineers say it is normal. Guys, there are degrees of normal and we should not be dismissed. We were driving about 1-2 mph over a parking lot bump. I think the system is pressurized enough for a static load but not a dynamic load.
If its not pressurized enough for a dynamic load, then it would act like a soft springs. The nose would dip after going over the bump.

It will lift. It lifts and stays lifted which tells me that there is a leak on the compressor side of the system.
Huh? That sounds like expected operation, and would indicate there is no leak? How do you conclude the opposite?

My theory is that at normal atmospheric pressure the car has enough gas for the compressor to pump through the one way valve to lift the car statically. This was confirmed when the first dealer had to reload nitrogen in the system. That dealer had to replace the damaged front spring shocks. My sway bar bushings also are shot but Chrysler will not replace. I was just out of warranty at 37k when the dealers finally started assessing. Two STAR reports later the engineers still claim normal.
Loud Bangs are usually parts contacting each other with force behind it.

Bumpstops are designed to cushion the impact of the suspension hitting its max limits, occasionally. Since its usually a rubber/poly bumper, it will make a noticeable Clunk Noise. If you're hitting bump stops often, its not designed to do that and eventually damage or premature wear happens.

Swaybar bushings wearing out prematurely is common on a lot of vehicles. Jeep likely designed the swaybar bushings molded to the bar to make them last longer. But on the flip side, that means you have to replace the entire bar when they do wear out, which is way more expensive. Changing ride height is going to stress the sway bar bushings more than when they are at rest at normal ride height.

Has anyone figured what is causing the loud bangs? Is it the suspension contacting something, hitting bump stops, the airbags (perhaps bouncing on their mounts) or something else?

Just doing a little simple math, at max height, there may only be 1.75" of rebound in the front suspension, with max spring rate, so I'm guessing going over bumps as the suspension rebounds, it runs out of rebound and hits bump stops.

Is it normal? It could be, but that means Jeep designed a suspension that didn't refine out loud bangs for going over bumps.
 
#26 ·
Have not figured out this forum page, cannot respond to you other helpful message directly. Hope this works.

If its not pressurized enough for a dynamic load, then it would act like a soft springs. The nose would dip after going over the bump.

First thanks for the replies and ideas!
It does act like soft springs; it is very bouncy until it hits the travel limits which it does quickly with a bank.


Huh? That sounds like expected operation, and would indicate there is no leak? How do you conclude the opposite?
I read an article on how the system works. There is a reservoir. When the up button is pushed, a valve opens and the compressor pushes nitrogen from the reservoir into the spring shocks, first the rear, then the front. When the car reaches the correct height the valve closes. When lowering another valve opens and the compressor moves nitrogen from the spring shocks back to the reservoir in reverse order. The compressor and the valve system are one unit. When the car reaches its lower height, this valve closes. If the reservoir is empty then the car would not raise. If there is a leak in any one of the spring shocks the car would not stay raised. However I theorized that there could be a leak in the reservoir or the supply lines leading to the spring shocks but the car would remain in its height position because the valves are shut, and the nitrogen in the spring shocks remains the same. if there is a leak on the reservoir side, the reservoir and the feed lines nonetheless would be pressurized to atmospheric pressure and the compressor could pump atmospheric gas through the larger valve opening to load the spring shocks, in theory. Chrysler engineers cannot ascertain how the system works because they have not designed a way to measure the pressure in the reservoir. As I stated after a period of time the dealer did add nitrogen to the reservoir demonstrating it had lost gas since the last refill.

Loud Bangs are usually parts contacting each other with force behind it.

Bumpstops are designed to cushion the impact of the suspension hitting its max limits, occasionally. Since its usually a rubber/poly bumper, it will make a noticeable Clunk Noise. If you're hitting bump stops often, its not designed to do that and eventually damage or premature wear happens.

Agreed I think that happened. Tell the engineers.

Swaybar bushings wearing out prematurely is common on a lot of vehicles. Jeep likely designed the swaybar bushings molded to the bar to make them last longer. But on the flip side, that means you have to replace the entire bar when they do wear out, which is way more expensive. Changing ride height is going to stress the sway bar bushings more than when they are at rest at normal ride height.

Agreed, yes $850 to replace the two sway bars with bushings.

Has anyone figured what is causing the loud bangs? Is it the suspension contacting something, hitting bump stops, the airbags (perhaps bouncing on their mounts) or something else?

Engineers say it is banging on the bump stops. Again the new cars on their lots do not.
Just doing a little simple math, at max height, there may only be 1.75" of rebound in the front suspension, with max spring rate, so I'm guessing going over bumps as the suspension rebounds, it runs out of rebound and hits bump stops.

Is it normal? It could be, but that means Jeep designed a suspension that didn't refine out loud bangs for going over bumps.[/QUOTE]
 
#27 · (Edited)
Have not figured out this forum page, cannot respond to you other helpful message directly. Hope this works.
Its HTML Code, the words with brackets around them make things act different, [] and then to turn off the you need [/].
Mongo53 said:
If its not pressurized enough for a dynamic load, then it would act like a soft springs. The nose would dip after going over the bump.
First thanks for the replies and ideas!
It does act like soft springs; it is very bouncy until it hits the travel limits which it does quickly with a bank.
I don't have QL, so I don't have experience. The posts I read about, in ORAII the QL is very stiff. I don't know if that is because the spring rate is high or the suspension is hitting the end of travel.

Keep in mind, the shock/struts are suppose to damp the bounciness. So by bouncy you mean after going over a bump, the vehicle bounces up and down several times, that is a lack of damping. Either the spring rate is too high for the shocks/struts or the shocks/struts or blown or weak and not damping enough.

Of if you mean by bouncy, the vehicle bounces once, but more than it should on every bump? Again a mismatch in spring rate and damping, either the airbags pressurized to much or something wrong with the shocks.

Mongo53 said:
Huh? That sounds like expected operation, and would indicate there is no leak? How do you conclude the opposite?
I read an article on how the system works. There is a reservoir. When the up button is pushed, a valve opens and the compressor pushes nitrogen from the reservoir into the spring shocks, first the rear, then the front. When the car reaches the correct height the valve closes. When lowering another valve opens and the compressor moves nitrogen from the spring shocks back to the reservoir in reverse order. The compressor and the valve system are one unit. When the car reaches its lower height, this valve closes. If the reservoir is empty then the car would not raise. If there is a leak in any one of the spring shocks the car would not stay raised. However I theorized that there could be a leak in the reservoir or the supply lines leading to the spring shocks but the car would remain in its height position because the valves are shut, and the nitrogen in the spring shocks remains the same. if there is a leak on the reservoir side, the reservoir and the feed lines nonetheless would be pressurized to atmospheric pressure and the compressor could pump atmospheric gas through the larger valve opening to load the spring shocks, in theory. Chrysler engineers cannot ascertain how the system works because they have not designed a way to measure the pressure in the reservoir. As I stated after a period of time the dealer did add nitrogen to the reservoir demonstrating it had lost gas since the last refill.
[/QUOTE]
Yes, that is how I understands the systems works, you're prevous post, you describe how the system reacts to being raised, which sounds like the way it should act and sadi that is why you think something is wrong with it. Which did not make sense.

The Engineers and Techs at the service department can determine how much nitrogen is in the system by doing a Mass Measurement Procedure (or term similar to that). Yes, if you have had to have nitrogen added to the system, and the techs didn't do it ignoring the published procedures (they sometimes pull this crap), if you really needed it, then it would have to be the result of a leak.

It's like an AC system, in the sense it requires a certain mass of working fluid (gas) to work efficiently and effectively. Just measuring pressures isn't effective, there are too many pressure differences in different parts of the system, pressure varies too much with the ambient conditions, etc, etc. So they come up with a test that indicates the actual mass of Nitrogen in the system. From what little I read, there is some sort of procedure they can do with the wiTech (scan) tool at the dealership using the FSM procedures to determine the mass of nitrogen in the system and service accordingly to get the correct mass.

I wouldn't put it past a dealership service department to not even open the book and just added a couple of PSI of nitrogen to the reservoir just guessing it might improve things.
Mongo53 said:
Loud Bangs are usually parts contacting each other with force behind it.

Bumpstops are designed to cushion the impact of the suspension hitting its max limits, occasionally. Since its usually a rubber/poly bumper, it will make a noticeable Clunk Noise. If you're hitting bump stops often, its not designed to do that and eventually damage or premature wear happens.
Agreed I think that happened. Tell the engineers.

Mongo53 said:
Swaybar bushings wearing out prematurely is common on a lot of vehicles. Jeep likely designed the swaybar bushings molded to the bar to make them last longer. But on the flip side, that means you have to replace the entire bar when they do wear out, which is way more expensive. Changing ride height is going to stress the sway bar bushings more than when they are at rest at normal ride height.
Agreed, yes $850 to replace the two sway bars with bushings.
Before these sway bars with the bushings molded on them, if got noise from the swaybars, typically you just replaced the end links and bushings. Didn't really worry about if only one was worn and not both, cause it only cost another $20 to replace the other while you're at to ensure no more noise from the swaybar.

So, the Dealer Service Department thinks the same thing, and it's not their money, so they quote you $850.

I had sway bar clunking, at 77k miles. I replaced my end links, since thats affordable, and prayed that it solved it and I didn't have to deal with the bushing. I was lucky, just the sway bar end links solved the problem. I did it myself for about $30. Of course I don't have QL either, and I can see how the QL stresses the bushings also.

Mongo53 said:
Has anyone figured what is causing the loud bangs? Is it the suspension contacting something, hitting bump stops, the airbags (perhaps bouncing on their mounts) or something else?
Engineers say it is banging on the bump stops. Again the new cars on their lots do not.
Have you inspected the bump stops on your vehicle? How many miles on your vehicle. Remember I said the bump stops are designed for occasional use. It's possible hitting bump stops often have chewed up the bump stops, and now they make loud banging noises, cause only half the bump stop is there. It's purely a guess on my part, but looking at the bump stops doesn't cost anything.

I suspect the bump stops on the front suspension are on the shock/strut, so you won't be able to inspect them. The rebound bump stop might be internal to the shock/strut, if so, likely it's not a very robust bump stop, and damage to the shock valving might have happened. And you say you're suspension is bouncy? Hmmm, related?
Mongo53 said:
Just doing a little simple math, at max height, there may only be 1.75" of rebound in the front suspension, with max spring rate, so I'm guessing going over bumps as the suspension rebounds, it runs out of rebound and hits bump stops.

Is it normal? It could be, but that means Jeep designed a suspension that didn't refine out loud bangs for going over bumps.
I don't know how common problems with the QL is, you can't go by internet forum posts as the statistics. People who have no problem with their QL aren't posting about it. But, there are a lot of posts and the more I hear, the more suspicious I get that it isn't really a good system or at least a durable system. If I'm right that ORAII leaves only 1.75" of rebound in the front suspension (and I could be wrong), I could see how using ORAII more than on rare occasions could result in early wear on the suspension.
 
#36 · (Edited)
Sorry, I didn't read the last couple of responses in entirety.

You're missing some basic concepts, the pressure in the spring is directly related to the ride height. The way they get the vehicle to raise is to increase pressure in the airbag, and lower it by reducing pressure.

If it has too much pressure, the vehicle would go higher, if doesn't have enough pressure it would not reach the proper ride height.

Even if the system had air in it, air is still 80% nitrogen. Regardless, the system simply increases/decreases pressure in the springs until a certain ride height is achieved. Again, only a certain spring rate produces a certain ride height. Two different pressures in the air bag spring can NOT produce the same ride height.

So, if you're vehicle achieves the proper ride height, the air bag spring has achieved the designed pressure, thus spring rate.

Even if it's all air in the system and not nitrogen, the difference in their performance would be extremely unlikely to cause the problems you're complaining about.

The Air Bags are no different than tires, you can't pump up a tire to remove the bulge in the sidewall and have a lower pressure in the tire. And the difference between air and nitrogen in tires produces very little difference in performance.

A leak in the reservoir? Well it would have to be a pretty bad leak to let out the nitrogen and then let in air, and then you're pump would have to run excessively long for the vehicle to reach the proper ride height.

I hate to say, but it really sounds like your shocks are worn out, that could cause the symptoms you're complaining about, including the bangs. I know its frustrating the dealership and engineers say its normal, it might be and replacing shocks often are normal for this system.
 
#37 ·
Anyone have a lot of experience/knowledge of Off-Road suspension design?

I know increased wheel travel is extremely important to improving off road suspension ability.

The QL doesn't change wheel travel, it just raises the ride height for more ground clearance and better approach/departure/peak angles. Which is an advantage, but not as much as more wheel travel, at least IMO.

I don't know about spring rate, I am of the impression that you want less spring rate for off-road, not more. But I don't really know. When you lift a vehicle with a spring swap, the lift springs are usually the same spring rate, or less than OEM, but the spring is longer to raise the vehicle, but provide the proper spring function.

The air bag can only raise the vehicle by increasing the spring rate, i.e. air pressure in the bag.

So that what's throws me about the QL, to raise the vehicle, they have to increase the spring rate. They ain't changing the springs, they are just making the spring stronger (more spring rate) so it extends more against the same force (weight of the vehicle) which results in the ride height raising. But results in very harshly sprung vehicle near the limits of its suspension travel in one direction. Which also sounds like a good recipe for blowing shocks.
 
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