Longer Air Bags

Red90 · November 03, 2015, 09:30 AM

I've been running air bags inside the rear coils of the 90 for quite a few years. It has been my preferred option. It lets you keep a light spring while maintaining ride height when you load up the truck. It does not let you have variable ride height like an air spring, but has the advantage that if you have a puncture, you are not disabled.

I've been happy with the performance and ride, but there have been some niggily things that I've wanted to address for a few years. Airlift and Firestone both sell kits. They are both a bit short for a stock 90 as I assume they are setup for a Stock Disco, which runs lower from the factory. Originally, I bought the Airlift kit (61741). It uses a 9" air bag. I then bought the Firestone kit (4121), which has a 10" spring to see if it gave a taller setup. They were both designed for the same height with different spacers. I've lost track of what went with what, But "I think" that they work out to about an 11" ride height for the spring itself. Anyway, I wanted to be more around 12.5". I mixed and matched air bag spacers and put in a 1" seat spacer to get where I wanted to be. A little messy, but functional.

There were a couple of problems that I wanted to fix. The upper bag retainer is a polyurethane block and has been slowly getting destroyed by the spring seat, so something more robust needed to be made. The second problem was the Firestone bag leaking. They use a push connect tube fitting. It is fine when clean, but a bit of mud and dirt and eventually, it leaks slowly. You can fiddle and clean and get it to seal or refill the air every day. A bit of a PITA. The Airlift bags use a barbed fitting, so have less chance to leak.

It has bounced around in my little brain that I should check with Airlift and see if they make a longer bag which would allow me to get rid of all the spacers. I was looking at air springs and noticed that TruckSpring, http://www.truckspring.com/Search.aspx?p=Suspension-Parts%2fAir-Springs-Kits%2fAir-Lift-Air-Bags&c=Air-Lift-1000 lists the bag sizes... Not only that, but they let you filter by size.... Seconds later, you see that Airlift makes a 12" bag at the same diameter. Kit 60818 with springs 60318 for 2009-2015 Dam Ram 1500s.

So I bought that kit and made up suitable upper and lower retainers and voila, new system. It is much cleaner and should hopefully be trouble free.... See the link below for some photos.

Air Bags | Land Rover Modifications | Red90's Photos! | Red90.ca
- Airlift kit 60818 (for 2009-2015 Dodge Ram 1500). Spring part number 60318. 4.35 inches diameter by 12 inches long.
- Using with genuine spring packers, ANR2938, top and bottom, which are 3/8" high each.
- Springs are NRC4304, which are supposed to be 170 pounds per inch and 17" long. Mine measure closer to 16.5". Being shorter than they are supposed to be led to the desire for the packers.

The setup is designed so that empty with no air, the truck sits at the height I want normally. I can then maintain this height with up to around 1100 pounds of load by adding air.

Trevor · November 03, 2015, 09:59 AM

That';s good info John, thanks for sharing. I've been looking at doing the same thing with the CT. The helper springs work great when loaded, but when unloaded the ride is just too firm. The airbag approach makes a lot of sense, and it also forces me to get moving with an on-board air system too...so double-win.

Red90 · November 03, 2015, 10:20 AM

Keep in mind 110s use a 7" spring versus the 6" of the 90. There are no airlift or Firestone kits for the 110. Polyair in Australia does one, but they are pricey ($350).

Doing a search at Truckspring, show the tallest Airlift of the right diameter is 10.5". http://www.truckspring.com/suspension-parts/helper-springs/air-spring-kits/air-lift/1000-60755.aspx Should work with a spacer for the bag. And an 11" in the Firestone http://www.truckspring.com/products/Firestone-Coil-Rite-Air-Bag-Kit-Nissan-Patrol-Rear__4129.aspx

Just had a quick look at the Polyairs in Australia. It sure looks like they are using the Airlift bags....same colour, same fittings, same design. I'm guessing they use the 10.5" bag listed above at three times the cost.

Red90 · November 03, 2015, 06:55 PM

I guess Airlift does do a kit for the 110 that you can buy through Britpart.

Matt H · November 03, 2015, 09:02 PM

Although hard to find and expensive these days the orginal self levelling strut as fitted to the Range Rover was one solution to this problem. It was a great idea, fully automatic and self energizing.

Trevor · November 03, 2015, 09:10 PM

Quote from: Red90 on November 03, 2015, 06:55 PM
I guess Airlift does do a kit for the 110 that you can buy through Britpart.

I was browsing through an Airlift parts list recently at JB's Automotive and they had the Defender 110 listed. Caught my eye because its not often you see anything Defender related listed here. JB's didn't have it in stock of course, and the guy wasn't sure he could even get it. My guess is it would be more cost effective going through Britpart via the club anyway, but they do indeed appear to exist.

Red90 · November 03, 2015, 09:42 PM

The one listed in North America for a 110 is wrong. It is the normal Rover one for 6" springs.

Red90 · November 03, 2015, 10:07 PM

Or maybe... It is strange. They list the wrong one in their application guide (61741), which is certainly for the 6" springs. But their online search gives 61724. But when you go to that page it show compatible with Defender 90 as well. Confusing in the least. The second one may actually be correct. Hard to say without seeing it.

binch · November 03, 2015, 10:09 PM

I wonder if Arnott industries make any kind of air bag to fit this bill. A lot of their products come with a lifetime warranty....very nice to have with a disco 11 ;-)

Red90 · November 03, 2015, 10:31 PM

These are not full air springs like that. You could do full air springs but that is a whole different topic. If anyone IS interested in full air spring conversions, let me know as I can provide some advice. It has been done a fair few times.

Red90 · November 03, 2015, 10:33 PM

Anyway. I sent airlift an email to clarify the part numbers and applications.

Trevor · November 04, 2015, 08:45 AM

Quote from: Red90 on November 03, 2015, 10:33 PM
Anyway. I sent airlift an email to clarify the part numbers and applications.

Excellent. I was browsing through the in-store parts manual at the time I saw them, and I don't believe it had any detail on contents...just description, part # (which I don't recall unfortunately), and pricing. Be interesting to hear what they say, hopefully they can unravel this.

Red90 · November 10, 2015, 11:55 AM

So.... I finally received a reply from Airlift. Their response was basically that they do not sell a kit for the 110.... and pointed me to their page with the bag sizes. https://www.airliftcompany.com/workshop/build-air-lift-1000-kit/

I sent a note back pointing them to the Britpart page which clearly shows they do make a kit and we will see what they say. I've also asked again what the 61724 is meant to fit.

Trevor · November 10, 2015, 01:14 PM

It's always entertaining dealing with companies who's left and right hands aren't sure what the other is doing.

Red90 · November 10, 2015, 01:41 PM

Quote from: Trevor on November 10, 2015, 01:14 PM
It's always entertaining dealing with companies who's left and right hands aren't sure what the other is doing.

In my experience, which is unfortunately, spending too much of my working life dealing with suppliers, is that only a few percent of companies know what they are doing. It amazes me every day how people stay in business.