QX4 rear bottoming out solution

[GFinger]

So I purchased my QX4 used, and like many of you, it bottomed out in the rear with any added weight. Driving by myself or with a passenger, it was fine. Add a third and it would start to bottom out often. 3 people in the back seat felt like it was riding on the bump-stops. I got really sick of this, so I started looking into the Air-Lift 1000 system, the rear spring inserts that are supposed to add payload capacity. The company makes several compressor options, but the one that caught my eye was the auto-leveling system, which they say is not compatible with the 1000 series. The reason for this is that the 1000 system was designed as a pressure monitored system. The 1000 series bags can only withstand a maximum of about 50lb. of pressure, and the compressor can output 150lb. of pressure. I thought ide give it a try anyway, risking a voided warranty.

This is a vauge description.If there is a lot of interest in this after it is posted, I'll try to get some pictures up.

The install of the 1000 bags was straight foward using the included paperwork. The auto leveling system was all custom, but I used factory brackets for the most part.I'll start with the compressor. I mounted it inside the vehicle behind the left rear panel. I also wrapped it in dynomat and filled the cavity with poly-fil to reduce the sound (the compressor is a bit noisy, but you can mount itunder the vehicle also.)Controller and wiring. I decided to wire the system to be active all the time. Instead of connecting the ignition wire to ignition, it is connected to the battery wire. (you can put a switch on this if you want) The harness is run down the left side to the rear of the vehicle and out the hole in the bottom of the left rear compartment where the compressor is mounted. The control box is mounted to the foward bracket in front of the spare tire. The sensor magnet was mounted to the bracket on the back of the diff using a thin metal strap that is thick enoug not to bend, and long enough for me to adjust the height.The release valve was straped to the frame and a long legnth of hose was ran through the fram to muffle the sound.

I adjusted the height to just above stock with an empty tank to keep 5lb of air in the bags at all times. I also used one of the tire-valve type things that came with the 1000 kit so I can check the pressure while I'm loading the back.

Results:AMAZING!!!!!! The ride is superb and improved on so many levels. It feels like a whole new truck! The ride is more stable, maybe a little stiffer in the rear, and does not roll as much in the corners. The added pitch also made it more stable on the highway. The only annoyance is the sound of the compressor turning on to level the system out every now and then, but it's worth it. When I have 3 people in the back, it feels like it is empty. I recently visited a few friends in Tallahassee, and we filled the rear with 2 full kegs, 250lbs of ice, and 4 passengers. I took a look at it from the outside after it was loaded, and it was sitting at the set height. You would NEVER have guessed that there was over 600lbs of payload in the car. With all of the weight, it felt a little hevier under acceleration and braking, but the ride felt wonderful on the hilly bumpy roads. Once it was unloaded, the system released the air to lower it back to the set height.

The best part of this setup is its fully automatic. I don;t have to do anything, it maintains the height all on its own. I recommend this to anybody that caries any extra weight in the back or tows anything.

[BurntTimber]

This is AWESOME timing for you to post this.

Currently I'm looking into doing the same setup for my 03 Pathfinder as I'm hauling a trailer (1500lbs) as well as using the Versahaul hitch hauler to bring my dirt bike. Needless to say 350 lbs of telescoped tongue load affects the rear suspension (though not near as much as I would have expected, go Nissan!).

I'm in Canada so I'll be ordering from Amazon.com and picking up in the states (as there's a 400% markup for the same setup at local distributors). I'm going to go with the Load Controller II instead as I'm not as concerned about the auto leveling.

I'd definitely love to see some pictures of your setup if you don't mind. I plan on posting pics and measurements showing the setup (trailer, bike mount, hitch) to give everyone the results (including specific tongue loads for everything).

Thanks in advance for what you can supply for info, and great description.

[keelhaul]

Im interested as well. I have an ac 2" lift kit but loaded with gear the back sags a bit. I already have an air compressor so I guess all I would need are the bags and some valves. I would like to see pics of them installed. Do they replace the bumpstops. Do you know know the height measurement of the bag? thanks

[GFinger]

I don't have any pictures yet, but I'll try to get some up soon. I bought all of my gear for this from Amazon, they had the best prices of any on-line retailer, and they had all of the compressor systems in stock. If you already have a compressor, then you need 2 valves, a pressure gauge, (the bladders will blow above 45lbs. according to AirLift) and their 5lbs. pressure switch to maintain 5lbs in the bladders. AirLift support is very helpful so if you give them a cal they can help you with your setup. As for the bumpstops, they were trimmed. The instructions say to measure about 6.5" from the bottom spring mount and cut the bumpstop there (while the vehicle is resting on the ground). I dodn't have to remove the springs for the installation and you can even pull out the bomp stops with a bit of pulling. After having it for a few more weeks, I LOVE this system. Although I think I'm going to move the compressor outside with an intake line going inside. The compressor turning on can get annoying, even though it doesn't come on often or stay on for long.

[fueler]

tell your girl to go on a diet

[bmlawless]

I have a much heavier duty version of these on my one-ton pickup. Mine are bolted to the axle and the frame. They've been able to endure axle twisting of a truck and camper totaling over 11,000 pounds without breaking.

I've had the system with the interior gauges and compressor for 5 years and it has been problem free. I bought my stuff from Summit Racing and eBay. For the record, you can also just get the bags and fill them with air from a gas station or bicycle pump. Just do me a favor and don't tie them together without one-way valves. If you don't use the valves, the air will transfer from one side to the other when cornering and you will tip more than ever!

I believe that the lighter versions are free at one end and will not limit the travel of your axle.

I would recommend buying the kit from AirLift rather than piecing one together if you already have a compressor. A lot of folks who have Rancho shocks and AirLift bags have tried to use one compressor. It can be done but it sounds like it's more trouble than it's worth. I have one compressor under my hood and the other mounted to a cross member under the truck.

[bmlawless]

Im interested as well. I have an ac 2" lift kit but loaded with gear the back sags a bit. I already have an air compressor so I guess all I would need are the bags and some valves. I would like to see pics of them installed. Do they replace the bumpstops. Do you know know the height measurement of the bag? thanks

They have adapters for lifts. http://www.airliftcompany.com/Lock-N-Lift.html

[GFinger]

They have adapters for lifts. http://www.airliftcompany.com/Lock-N-Lift.html

These are not the air springs that the QX uses.

I have not taken mine off roading where I need the low range yet, but on rough trails it is fine. The system basically works like an inflatable bump stop at the bottom of the spring rather than the top. So if there is a lot of wheel travel the bag will basically just be sitting in the rear spring.

[johny75]

So based on your review I just bought the AirLift 1000 also for my 1999 QX4 with the same bottoming out issue. I went to the Airlift website and the install video showed that you just compress the bag and wedge it into the coil and inflate, but I just got my kit today and the directions seem to call for a lot more work. My question to you is, did you have to remove the coil springs, brake lines, and shocks to install the bags like the directions in my shipment stated, or were you able to bypass that stuff and wedge it in there? Thanks for the info, I am tired of going over the rail road tracks and losing teeth. I don't have many teeth left. HAHA

[GFinger]

Nope, I didnt have to do any of that. The only thing I had to remove and midify was the bump-stop. I tried installing the kit with out cutting it, but it didn't ride well, and the bladder was very compressed. I left about 1.5" of the bump stops and re-installed them. I was able to pull the bump stop out of the spring, and yes, the bladder does squeeze through the spring. I deflated it and rolled it up as much as I could, then placed the cap over the air inlet, stuck it into the spring, removed and replaced the plug several times letting air in little by little while I manuvered the bladder in place.

[screwinitupagain]

There was a write-up on this over on PCOA about a year ago. If I can find the link I'll post it up.

[screwinitupagain]

Links to PCOA write-up

http://www.pcoa.org.au/forum/v...=3264

Bad-farkin-as$. These Aussies are funkin gangsta!

[johny75]

Awesome. Thanks for the reply. I will give it a shot this weekend if I have time. Any special tools you needed to cut the bump-stop?

[amaff]

Bringing this back from the dead! This is exactly what I'm looking for though. I tow my race car (miata, light weight), on a light, open trailer and the bottoming out has got to stop.

Couple questions about the AirLift-1000 because I'm thinking of just going the el-cheapo route and getting the bags and using an 'external' pump (12v, air tank, whatever):

Does the base kit come with 1 or 2 valves?
If it only comes with one, are there check-valves in place to prevent swaying under load?
Does it come with a mounting bracket to put the valves up under the rear bumper? I'd love to bolt it to the hitch a-al PCOA like the pics in that previous post.

Thanks for your time

~Andrew

[amaff]

These are cheap enough that I went ahead and ordered a set. I'll update this thread once I get them. I'm really looking forward to not riding on the bumpstops anymore haha

[ganesh21]

These are cheap enough that I went ahead and ordered a set. I'll update this thread once I get them. I'm really looking forward to not riding on the bumpstops anymore haha

any update? I am thinking about picking this up. After install all the music, it drop the rear almost 2-3 inches.

[amaff]

Yeah: They're sitting on my livingroom floor waiting on a day for me to be able to install them. They may have to wait a little while. I'm out of town for father's day this weekend, out of town (towing the race car) next weekend. That said, the race car's heading to the fabricator for some serious work after that and will be gone for about a month, so my best bet is probably sometime after that.

~Andrew

[amaff]

That said, looking at it the only thing I'm not 100% on yet is how I want to mount the valves. If anyone has any pictures (preferably) or insight, it would be much appreciated. I have a few ideas, but I haven't gotten under the truck to actually have a good look-see at what's around, so at this point I'm doing the lazy thing and phishing for ideas.

Ideally I'd like something similar to what's on the link from PCOA (crap pictures ftl...). I've got the materiel to fab up that plate (c-clamp and drill press), but oddly enough, I don't actually have a drill to do the holes in the hitch lol. Sad, I know.

The other viable alternatives in my head are mounting them on either side of my 7-pin connector, or in the wheel wells.

So yeah... any pictures would be appreciated

[amaff]

Bump for the day crew. Thoughts?

[amaff]

I think I've got a coupe of locations picked out, but I'm concerned about routing around the exhaust on the passenger side. I may need to pick up some more hose, but it should be fine, if a little close. The driver's side looks like it should be cake to install, while the passenger side is a bit more cluttered. The hose definitely fits through the bottom of the spring perch on both sides, for those who had that concern. Doesn't look like any drilling will be required, nor any suspension disassembly (exactly as described by the OP).

My only other question I have is this: I need to get the weight of the body off of the suspension to install these. That said, I can use the pumpkin or suspension pickups on the axle as a jacking point, but I need somewhere else to put the jackstands on the body. Any thoughts? I don't know of any jack points on the actual chassis in the rear, so any help would be appreciated.

[WPGQX4]

I hate to do things that aren't 100% safe. You could use a piece of 2x4 to distribute the weight( so you don't bend them)across the pinch weld on the rocker. Balance the 2x4 on the jack stand. Make sure to chock the wheels so she doesn't roll off the jack stands.

[amaff]

I hate to do things that aren't 100% safe. You could use a piece of 2x4 to distribute the weight( so you don't bend them)across the pinch weld on the rocker. Balance the 2x4 on the jack stand. Make sure to chock the wheels so she doesn't roll off the jack stands.

It was fine. Jack it up under the rear axle, and put a jack-stand under each of the big "frame rails" that run down the side.

Install was actually pretty simple. the hardest thing to figure out was how to route the passenger side lines so that they don't get near the exhaust. I mounted the valves in the fender wells, a little above the detachable "mud guards" on the inner liner. The higher you mount them, the more support there is on them for you to push on. Aired them up and they seem to hold pressure fine.

About the only thing I had trouble with was getting the bump stops out of the springs (no, I didn't remove the springs). About a minute with a sawzall (taking time not to nick the springs lol) took care of that (cut 'em in half, both pieces fit through the springs without trouble.

Honestly, the hardest part of the whole job was getting the truck up off the ground using the damn stock scissor jack LOL (I forgot to bring my floor jack )

No driving impressions yet, but I'll be driving back to Atlanta (from Auburn, AL) tomorrow, and I will be towing the race car down to Atlanta Motor Speedway next weekend, so I should have a few solid data points then.

[amaff]

So far I have to say I am nothing short of pleased with the fruit of my efforts. Bumped it up to about 14 PSI Saturday night. As of this morning they were both holding steady at 13 (it's also cooler than it was when I pumped them up). The ride is so much nicer now over large bumps (like on interstate bridges, etc). I haven't tested the load-leveling capabilities, but so far I'm confident that they will work just fine. Towing impressions will be next weekend, as I'll have just under 3000 lb worth of trailer / race car / gear for an hour each way down to Atlanta Motor Speedway and back

Cliff's notes: the AirLift 1000 is a good mod

[amaff]

Ho. Ly. Balls.

Towing with the air-bags is a whole different experience. No more suspension "crashing" over bumps on the interstate. Braking's a lot better with more weight on the front tires, much better steering feel (for the same reason), and the entire rig just simply feels stable.

Besides when there are hills, you don't even for real notice that you've got a whole nother car behind you. I was impressed with how my 03 Pathy towed before I installed the bags, considering it's a short wheel base truck with not really *that* much power to it (compared to a full sized truck / V8), but now all things considered, I'm pleasantly amazed

A couple of crap pictures to sort of illustrate what I'm talking about:
Hard to tell here, but you can look closely and see just how "slammed" the rear is. Full stock suspension.



With the AirLift 1000:



There went from being 4 or 5" of droop with the stock springs / bumpstops (and riding entirely on the bumpstops...), to about a half inch of droop with the exact same load-out on the truck & trailer. It hardly looks like there's anything on the tongue at all. IIRC I used 25 PSI to tow with. I usually leave them at 10 PSI for daily use. Impressive what $75 and a couple hours of labor can gain you

[Travis QX4]

Nope, I didnt have to do any of that. The only thing I had to remove and midify was the bump-stop. I tried installing the kit with out cutting it, but it didn't ride well, and the bladder was very compressed. I left about 1.5" ..... and yes, the bladder does squeeze through the spring. I deflated it and rolled it up as much as I could, then placed the cap over the air inlet, stuck it into the spring, removed and replaced the plug several times letting air in little by little while I manuvered the bladder in place.

Did you install them with the fill valves pointed up or down?