2008 Denali Sagging?

[Quimbola]

My rear end is sagging on the denali, it sits about an inch lower than the front.

I don't have any error codes, the compressor runs for about 30 seconds when the car starts up. When I am towing it also pumps the rear up but still sits about an inch lower.

I looked at the rear shocks and the rubber diaphragm looks fine.

The truck also doesn't sink or sag if it sits for awhile so I don't think it is a leak.

What can I look for or do to level it?

Thanks in advance!

 

[Quimbola]

Anyone?

 

[THE YETI]

How many mile? Might need new struts?

 

[Floep]

Adjust the level sensors for the rear bags

 

[GM Customer Service]

Quimbola,

Do you have the Autoride feature? The shocks used to level the rear suspension may need to be replaced. Rear springs is another possibility. These are just suggestions. I recommend having the vehicle inspected by a certified technician for an accurate diagnosis.

Please keep us posted.

Louis
GM Customer Service

 

[Quimbola]

Level Sensors?

Adjust the level sensors for the rear bags

How do you adjust those?

The vehicle does have autoride, and has about 85k on it.

 

[KMeloney]

How do you adjust those?

The vehicle does have autoride, and has about 85k on it.

Unless you've had the truck lowered, and those links have already been shortened, you're not going to want to mess with them.

It sounds like your rear shocks are shot, and are no longer holding air.

 

[gnarpow]

30 seconds is a long time for the compressor to run, especially if there's not much weight in the back

 

[stevek]

Yeah my compressor runs for maybe 5 seconds... at most.

 

[gnarpow]

My rear shocks are shot, I actually have some Arnott/ Bilstiens that should be at my house on Friday.
That said, my rear doesn't sag really at all. If I have a load in it, the rear will sag until I turn the truck on and it will pump up. With 6 adults it takes about 15-20 seconds.
The reason I know my shocks are bad is when loaded it pumps up again every 2-3 minutes.

If your truck isn't loaded down and it is sitting a inch lower you may have a spring problem to look into.

 

[Quimbola]

Wouldn't the autoride give me an error?

 

[KMeloney]

Wouldn't the autoride give me an error?

Not sure, 'cause the shocks can operate fine without much air pumped into them. So, if you have a slow leak, then maybe you wouldn't get a warning. When my front shock crapped out, apparently there was fluid leaking from it, and I got the error light.

 

[quattrotman]

I think your springs are sagged. Shocks aren't really going to affect the ride height especially when stationary. the springs hold the vehicle at a certain height. The bags will air up and help with that but when the air is out of them, the springs will dictate the height. Maybe they are sagged from overloading but I have to admit, that condition is pretty rare. Springs are a lifetime part and never need to be serviced. Have any rust issues? Perches rusted?
Remedy, get a new set of OEM springs and throw them in. Cheap and easy to do.

 

[Quimbola]

Interesting, I'll take a look at the springs.

Another intersting thing happened this weekend.

The compressor did kick on this weekend and souonded like it was going to BLOW UP!! LOUD and only was on for about 10 seconds.

Loud as in, shut the car off loud!!

I wonder if the compressor is shot and not pumping it up to height?

 

[Quimbola]

So, shocks look fine, compressor looks ok.

OEM the best way to go for new springs? Best place to buy online?

Thanks in advance!