Air Support Springs
January 2006
With my racing project for 2006 moving
forward rapidly, it's time for me to make sure my tow vehicle is in tip
top shape.
First I picked up a Class 3 (5000 lb) hitch from 4x4parts.com.
The hitch was well
made and seriously heavy duty, install was very easy, especially if you
have a helper and better yet a lift, and cost was just $115.
Next, because yes I am going to overload the official Nissan towing specs by a bit, I got a Air Lift Rear Coil Support kit also from 4x4parts.com.
It's really a very simple setup, small plastic airbags go inside the rear coil springs, add air when needed to support the springs and wa'la, less or no sag in the rear when you've got a big load.
The directions were weak, but the install was reasonably easy for the mechanically inclined, and the results were visibly obvious with a test load of 500lbs in the trunk (thanks Rav & Rohith! ;-).
The air lines come out the bottom of the spring perches, then I zip tied them to the EBrake lines. The duct tape is for a little extra protection from debris & heat.
On the passenger side, I ran the air line from the EBrake bracket over the rear Diff, notice how I'm aiming for rounded metal and not any sharp corners which might cause abrasion over time.
On the driver's side of the diff, zip tied to the EBrake line is the T connection, left and right to the two bags and the top snaking up and around to the filler valve.
Wider shot of the driver's side rear diff area.
Close up of the bottom of the driver's side spring perch.
Between the top of the perch and the airbag is a 1/2 inch thick pancake of plastic with a hole in the middle to protect the brass nozzle which the airline connects to.
This is with 40psi in it. "max" is 35, but I thought it made sense to stress test it a bit while hanging up in the air.
The air line snaking up to the fuel filler door.
Back side of the fuel filler door.
Felt very painful to drill a hole in my Mo, but the results did turn out pretty clean.
Unladen
Roughly 500 lbs of weight on the tail with airbags soft.
Same 500 lbs, but with 35psi in the air bags.
Photoshopped load comp pics, left to right unladen, 500# with air springs, 500# without air springs.
-c
Next, because yes I am going to overload the official Nissan towing specs by a bit, I got a Air Lift Rear Coil Support kit also from 4x4parts.com.
It's really a very simple setup, small plastic airbags go inside the rear coil springs, add air when needed to support the springs and wa'la, less or no sag in the rear when you've got a big load.
The directions were weak, but the install was reasonably easy for the mechanically inclined, and the results were visibly obvious with a test load of 500lbs in the trunk (thanks Rav & Rohith! ;-).
The air lines come out the bottom of the spring perches, then I zip tied them to the EBrake lines. The duct tape is for a little extra protection from debris & heat.
On the passenger side, I ran the air line from the EBrake bracket over the rear Diff, notice how I'm aiming for rounded metal and not any sharp corners which might cause abrasion over time.
On the driver's side of the diff, zip tied to the EBrake line is the T connection, left and right to the two bags and the top snaking up and around to the filler valve.
Wider shot of the driver's side rear diff area.
Close up of the bottom of the driver's side spring perch.
Between the top of the perch and the airbag is a 1/2 inch thick pancake of plastic with a hole in the middle to protect the brass nozzle which the airline connects to.
This is with 40psi in it. "max" is 35, but I thought it made sense to stress test it a bit while hanging up in the air.
The air line snaking up to the fuel filler door.
Back side of the fuel filler door.
Felt very painful to drill a hole in my Mo, but the results did turn out pretty clean.
Unladen
Roughly 500 lbs of weight on the tail with airbags soft.
Same 500 lbs, but with 35psi in the air bags.
Photoshopped load comp pics, left to right unladen, 500# with air springs, 500# without air springs.
-c