Converting back the Z55 Air Ride Suspension

[91RS]

Have they stayed at that height, and how long has it been? I know new springs will settle a bit.

I haven't measured again and not sure if I still have where I wrote down what the measurements were. The trucks both still look good to the eye, that's what made me replace them in the first place because they didn't look quite right after doing a 2/3 drop.

 

[ivin74]

I completed the replacement of the compressor, the rear shocks and the rear springs. I connected the air shocks to the compressor, but I did not connect the electrical connectors to the shocks, as I am awaiting receipt of a salvage set of electrical connectors. All went relatively smoothly, and I did not get the opportunity to invent many new swear words.

When I started the truck, though, it threw a bunch of DTC codes, with the ABS light being the most unexpected code. I diagnosed it with my Tech 2, and I narrowed it down to the rear driver's side wheel. So, I jacked up the truck and pulled off the wheel, and I found that the ABS connector on the frame had become disconnected somehow from the wire running to the wheel hub. Once I reconnected it, all the trouble codes went away.

I then used my Tech 2 to re-set the automatic level control trim on the truck.

Next week, the front suspension components will be installed.

So far, so good.

No pics, I didn't happen. Tyf rules.

 

[ivin74]

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
The ride is going to ride stiff until you get the electrical connectors installed. Are you running the SUSPENSION FUSE aka RTD? The BCM reads the yaw rate sensor, speed sensor, steering wheel position sensor, height sensors and makes adjustments based on their readings. If one of those items does not read correctly the BCM puts the system in limp mod, basically makes the system stiff. Hope this helps

 

[Joseph Garcia]

@Joseph Garcia
The ride is going to ride stiff until you get the electrical connectors installed. Are you running the SUSPENSION FUSE aka RTD? The BCM reads the yaw rate sensor, speed sensor, steering wheel position sensor, height sensors and makes adjustments based on their readings. If one of those items does not read correctly the BCM puts the system in limp mod, basically makes the system stiff. Hope this helps

I'm running the 4 resistors, until I can get the recently acquired electrical connectors re-connected to the source wires (Thanks again @TollKeeper !!). I hope to complete this work by the end of next week.

 

[TollKeeper]

Any luck with your repairs?

 

[Joseph Garcia]

The two electrical connectors that you acquired for the rear shocks fit and connect perfectly. The two front connectors fit physically; however, they do not make physical contact with the shock's electrodes. Apparently, there was a connector change for my model year. As such, I am having to build my front electrical connectors from scratch. So, for now, the project is on hold, as I want to install all 4 electrical connectors at the same time.

That's where the saga begins. :-(

I was able find the correct electrical connector, but it was a bare bones connector shell, needing the electrical contact pins to be purchased separately. The connector shells were $.37 each, but they must be purchased in minimum lots of 50. Ok. Still an economical purchase. As I was checking out, I got an error that there was also a $25 minimum purchase amount per order. So, I increased the order size appropriately to 70 connector shells, to get over the minimum order purchase. The order was placed, and it was to be shipped by Federal Express, and was to be delivered in 2-3 days.

That was a week ago. My vendor is located in PA, and the order was picked up by Federal Express on the 16th and taken to their PA distribution center. Then, the order was shipped to the Federal Express distribution center in Bloomington, CA, and it has been sitting there since the 20th! I called Federal Express yesterday, and they did not have any logical answers for why my order is sitting in a Federal Express distribution center in CA, but they did place an escalation on my order, to try to resolve it. No change as of today. If this is not resolved by Federal Express within the next day or so, I'll place another order with the electrical connector shell vendor.

I went through a similar exercise with the electrical contact pins, and I had to order a minimum of 50 electrical contact pins to complete the purchase. Fortunately, the electrical connector pins arrived on time, and are awaiting the arrival of the electrical connector shells, in order to assemble the complete connector assembly, along with the 16 gauge electrical wire, which I already have on my possession.

If anyone needs any of these electrical connector shells, or any of the electrical contact pins, I have MANY of them, and I will ship them to anyone who needs them.

 

[TollKeeper]

I might be able to help you on this one... But I cant swear to it, until I try.

But I know I have seen a couple 2007+ models that were being parted out. No idea if they have the Z55 systems until I go and look. But they may be cheap.

Then over in Rancho Cordova CA, their is a junkyard that has a lot of GM SUV's. And they do ship I believe.

ALL AMERICAN AUTO DISMANTLING
11355 DISMANTLE CT
Rancho Cordova, CA 95742
916-800-5015

 

[iamdub]

The two electrical connectors that you acquired for the rear shocks fit and connect perfectly. The two front connectors fit physically; however, they do not make physical contact with the shock's electrodes. Apparently, there was a connector change for my model year. As such, I am having to build my front electrical connectors from scratch. So, for now, the project is on hold, as I want to install all 4 electrical connectors at the same time.

That's where the saga begins. :-(

I was able find the correct electrical connector, but it was a bare bones connector shell, needing the electrical contact pins to be purchased separately. The connector shells were $.37 each, but they must be purchased in minimum lots of 50. Ok. Still an economical purchase. As I was checking out, I got an error that there was also a $25 minimum purchase amount per order. So, I increased the order size appropriately to 70 connector shells, to get over the minimum order purchase. The order was placed, and it was to be shipped by Federal Express, and was to be delivered in 2-3 days.

That was a week ago. My vendor is located in PA, and the order was picked up by Federal Express on the 16th and taken to their PA distribution center. Then, the order was shipped to the Federal Express distribution center in Bloomington, CA, and it has been sitting there since the 20th! I called Federal Express yesterday, and they did not have any logical answers for why my order is sitting in a Federal Express distribution center in CA, but they did place an escalation on my order, to try to resolve it. No change as of today. If this is not resolved by Federal Express within the next day or so, I'll place another order with the electrical connector shell vendor.

I went through a similar exercise with the electrical contact pins, and I had to order a minimum of 50 electrical contact pins to complete the purchase. Fortunately, the electrical connector pins arrived on time, and are awaiting the arrival of the electrical connector shells, in order to assemble the complete connector assembly, along with the 16 gauge electrical wire, which I already have on my possession.

If anyone needs any of these electrical connector shells, or any of the electrical contact pins, I have MANY of them, and I will ship them to anyone who needs them.

Duuuuuude. I've missed out on this thread or I would've spoke up sooner. I think I still have all four of my shock/strut connectors and would've sent 'em to you.

 

[TollKeeper]

There you go! @iamdub to the rescue!

 

[iamdub]

@Joseph Garcia, if you're interested, post up some pics of your front connectors in question and I'll compare to what I have. Maybe ID numbers on the connector itself. I deleted all of that when I lowered mine and I know they worked cuz the shocks and struts went super soft when I unplugged them during a test.

 

[Joseph Garcia]

Duuuuuude. I've missed out on this thread or I would've spoke up sooner. I think I still have all four of my shock/strut connectors and would've sent 'em to you.

Thank you for your offer. About an hour ago, I said 'screw it', and I ordered a second batch of electrical connector shells. If this 'make your own' effort fails, I'll reach out to you with photos of what I need. Again, I do thank you for your offer, though.

 

[Joseph Garcia]

As luck would have it, my second order of a set of electrical connector shells arrived on one day, and the original 'lost' order of a set of electrical connector shells arrived the following day. So, I ended up with 140 electrical connector shells, when I only needed 2. But, at least I had what I needed. I assembled the pigtail assemblies needed for the front struts, using these electrical connector shells and the appropriate contact pins and 16 gauge wire.

I completed the electrical portion of the suspension conversion back to the OEM Z55 specification, and now this project is complete. Another thanks to @TollKeeper for his help in acquiring some of the required electrical connectors at the salvage yard, and thanks to all of the rest of you folks who followed this project and provided input. Very much appreciated.

My understanding is that these electrical connector shells are also used on other parts of the electrical systems for the GMT900 platform. So, if anyone is interested in having spares of these electrical connector shells, and contact pins, just let me know, and I will send them to you for free.

 

[George B]

As luck would have it, my second order of a set of electrical connector shells arrived on one day, and the original 'lost' order of a set of electrical connector shells arrived the following day. So, I ended up with 140 electrical connector shells, when I only needed 2. But, at least I had what I needed. I assembled the pigtail assemblies needed for the front struts, using these electrical connector shells and the appropriate contact pins and 16 gauge wire.

I completed the electrical portion of the suspension conversion back to the OEM Z55 specification, and now this project is complete. Another thanks to @TollKeeper for his help in acquiring some of the required electrical connectors at the salvage yard, and thanks to all of the rest of you folks who followed this project and provided input. Very much appreciated.

My understanding is that these electrical connector shells are also used on other parts of the electrical systems for the GMT900 platform. So, if anyone is interested in having spares of these electrical connector shells, and contact pins, just let me know, and I will send them to you for free.

View attachment 349083

View attachment 349084

If you make up pigtails you can probably sell them on ebay.

 

[TollKeeper]

Waiting for the follow ups to see how it rides!

Glad we could help with the restoration back to stock, hopefully it pays dividends.

My Z55 to Z95 is going OK thus far. But I think my front shocks need replacement maybe.. They arent leaking fluid, and I dont have any "suspension" service lights on. But the spring rebound in the front is a LOT over the rear. I dont know if this is just the nature of the beast because of the torsion springs, or my shocks, or? I still have my OEM Z55 shocks on the front.

 

[George B]

@Joseph Garcia
How does it ride now?

 

[Joseph Garcia]

@Joseph Garcia
How does it ride now?

I only took a very quick ride after completing the installation, to see if any codes got thrown, and there were none. I checked out the suspension with the Tech 2, and the damper actuators comm's were working. I'll take the truck out for a more substantial test ride soon, including my test cloverleaf, and report back in this thread.

 

[George B]

I only took a very quick ride after completing the installation, to see if any codes got thrown, and there were none. I checked out the suspension with the Tech 2, and the damper actuators comm's were working. I'll take the truck out for a more substantial test ride soon, including my test cloverleaf, and report back in this thread.

Did you do a trim cal?

 

[TollKeeper]

Did you do a trim cal?

Can you please remind me how thats done. I imagine it needs to be done on mine as well.

 

[George B]

Can you please remind me how thats done. I imagine it needs to be done on mine as well.

It’s done with the tech2 in the suspension section.

https://f01.justanswer.com/dcraig1000/01f657c2-9509-4fb1-8b17-0573655e04ed_eee1.pdf

 

[Joseph Garcia]

Did you do a trim cal?

Yes, I did an ALC trim cal procedure with the Tech 2, when I first completed the rear air assist work, and then I repeated the action, after I completed the electric portion of the project, though it probably was not necessary the second time.