JPTL

I have the Z55 Autoride system on my '07 Suburban LTZ.
Although I haven't experienced noticeable issues with the compressor running, ***-end sagging, etc. there's a noticeable lack of firmness in the front suspension. There's a significant bounce/lack of dampening when going over dips in the road - even at highway speed. It's noticeable in the front, but I can't say for sure if this bounce exists in the back.
This is becoming a dangerous condition affecting handling/driveability. Furthermore, I use this beast to trailer a 23' Cuddy on a tandem axle trailer to and from Maryland to Maine, so good/properly working suspension is critical.
With 160k on the original shocks, I have to assume that they're due for replacement at all four corners.

Here are my questions:

• Assuming that this is correct:
  Autoride: indicated by the RPO code Z55. This suspension system uses electronic shocks in the front that automatically adjusts to road conditions, becoming stiffer or softer as necessary. The rear will use an electronically controlled self leveling air shock that is monitored by ride height sensors and inflated remotely from an on-board air compressor.
  Should these shocks always be replaced as a set (fronts & backs) using the same brands, or have some folks put different brands on the front & back?
  
• If the front suspension is bouncy, lacking dampening, could this be a sensor issue not directly related to the shocks; if I replace the shocks could I still experience the issue?

I've read the debate between the oem/factory Autoride replacements and the Bilstein replacements, and can't really get a sense about the differences, benefits and/or disadvantages of either option. I become further confused when I look at my options via an online supplier...here for example
If someone has an informed opinion on replacement options, that would be great.
J.P.

73shark

Welcome to the forum.

Check out Arnot.

Joe In NY

Ah yes. What most likely is going on is that the shocks are wearing out just like regular ones and also the solenoids are probably failing. We have a intermittent solenoid failure on our front left shock but it is a minor code that doesn't set anything off. But at 134K I am noticing that the front is starting to lack firmness on our as well. I would suggest if you haven;t already buying the rear and front shocks from Arnott and buy the Bilstein ones. They internally and mechanically adjust them selves so they last longer than the oem shocks and if the suspension computer dies (which is common with some age) your shocks will still be working perfectly fine.

I did the rear Bilsteins on our burb, ride was noticeable better than oem. Waiting to do the fronts. One unfortunate thing though, the price at Arnott has gone up since I bought the rear shocks and compressor from them (by quite a bit too!)

JPTL

I contacted Arnott tech support and got a knowledgeable CS rep on the phone. He was very helpful in describing the differences between the oem shocks/system and the Bilstein replacements. I have Bilsteins in two of my sports cars and know them well.
At this point, since I'm not having any issues with the rear shocks/compressor (knock on wood), I'm just doing the fronts. Since I tow with this vehicle, when the time comes to replace the rears, I'd want to stay with the air adjustable shocks as opposed to the coilover replacement kit.
Joe, it looks like Shockwarehouse.com has the SK 2671 for 20% less than Arnott...at least at this point. I didn't look into pricing for the rears. I don't feel too bad buying from them as opposed to directly from Arnott since I have to imagine that SW is a retailer for Arnott.

Joe In NY

I bought ours from Arnott because, well, I couldn't find them cheaper! And they included shipping label to ship out the cores to get my $50 back (included in price, so its $50 less what they show)... I would stay with the rear air suspension as well. It looks nice that the rear isn't always jacked and you can load it up and it sits exactly where it should.

Oh, don't forget. Conn. Just passed double digit minimum wage! Yay, here comes extreme inflation!! (ahhh!!)