Converting back the Z55 Air Ride Suspension

Joseph Garcia

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Initial Assessment - Rear Suspension Z55 Upgrade

Old: Original Z55 springs and Suncore coil over shocks (no air, no electric, and one shock leaking)
New: New Z55 springs and new Z55 air/electric shocks (air connected, but no electric yet)

I've had the new rear Z55 shocks and springs installed, and I've driven about 20 miles on various country roads for my initial assessment.

The rear of the truck sets about one inch or more lower, but the truck is now essentially level. The ride is a bit stiffer than before, but not at all an issue. The replacement Dorman compressor is VERY quiet, much quieter than the original compressor. You actually have to listen to hear it kick in, a few seconds after the ignition key is switched to on.

I'll post an update after the front suspension is upgraded to Z55, and the electrical connecters are in place and operational.
 

Joseph Garcia

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The suspension replacement work (except for the electrical) is complete for the front end of my truck. New control arms, new ball joints, new springs, new struts, and new related suspension accessories. The truck rides well, but perhaps with a little bit stiffer ride, presumably because of the new struts.

I'll be tackling the last part of the project shortly - the reconnection of the electrical portion of the Z55 suspension.
 

Joseph Garcia

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The springs presumably had 140k+ miles of wear on them, and while I had the entire strut assembly apart, and replacing every other component of the strut, including the top mounts, I figured that it made sense to replace the springs, as well. The OEM springs are no longer manufactured, so I used Moog springs.
 

91RS

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Quick question.. Why did you replace the springs?

Springs wear out. New springs raised the front of my 150k mile 2008 3/4” and raised the front of my 185k mile 2012 1” and both ride significantly better. I used OEM springs but I bought some of the last ones available.
 

swathdiver

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Springs wear out. New springs raised the front of my 150k mile 2008 3/4” and raised the front of my 185k mile 2012 1” and both ride significantly better. I used OEM springs but I bought some of the last ones available.
I was lucky to get GM OE springs for the front but had to get ACDelco Professional springs for the rear, no more anywhere after months of searching. In another twelve years I reckon we'll be forced to run Moog!
 
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Springs wear out. New springs raised the front of my 150k mile 2008 3/4” and raised the front of my 185k mile 2012 1” and both ride significantly better. I used OEM springs but I bought some of the last ones available.
Have they stayed at that height, and how long has it been? I know new springs will settle a bit.
 

PNW VietVet

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I recently replaced my rear springs with the Moog 81069 set. They went 1.25" higher but after about 6 months of hard driving, they have settled 1/2" at this point.
 
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