Posted by Mark Hawley
on August 03, 2025
Stock height rear coil springs, needing a little extra load capacity not to sag when towing or temporarily carrying a heavy load? This can be fixed by adding internal aftermarket airbags that go inside the rear springs.
This allows us to have the comfortable ride of a stock rear coil spring vrs. A stiffer spring when we don't need it. The internal airbags can be "bagged" up easily with a standard air compressor. These kits have airlines and standard shreader valves to add or remove air. 5-30 PSI is all that is needed, depending on the load you are carrying. The key is getting the correct internal airbag for this system to work correctly.
To install:
The internal airbag kits are straightforward to install if you follow our video guide on installing rear coil springs.
Yes, this video is how to REMOVE stock suspension airbags, but the process to install internal airbags in coil springs is the same, as you need to remove the stock coil springs first. Remove the Toyota secondary rubber cone at the top of the stock springs; this is no longer needed. Save them, as in the future you may wish to revert back. Conect the airlines as per the kit's instructions and route them to where you want to mount the shreader valves. Most mount them right to the side of the receiver hitch. Reconnect your shocks and swaybar. Done!
To use:
With your vehicle sagging due to temporary weight, add air until it's at the desired ride height. Only add air to the level once there, and note the PSI. Usually, it's not much like 10 to 15lbs for most loads. When you are done towing or having the extra load, let the air out. You can use the tip of a key to depress the center of the shudder valve; it's easy, as it's such low pressure. Repeat when you need the extra capacity.
You can get systems with small air pumps and in-cab controls. However, cost and complexity come in. Its far easier to keep it as simple as possible. Get a quality 12v off-road tire air compressor to make it easy to bag up when ever you want. You need CFM (cubic feet per minute), not high pressure, and why get an off-road tire type compressor Or keep it extra simple and just use the compressed air at the gas station.
Links to recommended rear helper airbag kits on Amazon:
The kits linked may say a different vehicle, but they are all 100% confirmed to fit what we have them listed as.
GX470 and GX46 (yes this will fit a GX470 they say only 460 but it fits)
This compressor linked to Amazon is sold under many different brands/colors, but they are the same units, just sold anywhere $50-100 more. This is a decent price for a compressor that will fill quickly and has a gauge on the fill line at the point you're adding the air.
NOTE: For lifted trucks, we can track down internal airbags made for other vehicles that are taller that then fit our lifted springs. However, internal airbags do limit our flex off-road. Also, if you run your truck on the trail a lot and flex it out a lot, you may have an early failure rate for the airbag systems. We just have to keep this in mind if we have a lifted spring. To find the kit that will fit your spring: This is best done by contacting the manufacturers of the airbag systems and telling them your spring inner diameter and how tall the open space is at ride height. They can cross-reference their kits to find one that will fit your configuration.
https://amzn.to/3Uby11W