ZW7 "Premium Smooth Ride" on a '02 Suburban LS

[SpitShine_PL]

I pulled the trigger too fast at asked about this in the Envoy etc. section, but...

My 2002 'Burb has ZW7 on the RPO list, it's "Premium Smooth Ride".
There is no evidence of any wiring for the rear shocks, or air lines, or that any air compressor was ever factory installed in the car.
I think ZW7 is the Nivo shocks for the large trucks, like these:
More Information for SACHS 444232
I understand they are self-contained, auto levelling oil shocks that lift the ass under load about 100 yards of driving from park. Am I correct?

 

[TollKeeper]

Its not a 100 yards, it does take a but more of a drive. But yes, they pump themselves up within 2-4 miles.

 

[SpitShine_PL]

Gotcha. This sounds good. There are only a few things worse than sloppy steering from the lifted nose, at least in my personal ranking.
What is the ballpark service life of the Nivos? (I know the answer might be that it's manufacturer-dependent) 80-100k miles?

 

[azswiss]

Got 165K miles out of them on my 2003 Suburban. Note, if you are considering swapping out the Nivo's for standard shocks you also need to swap the coil springs since they are designed to work together.

 

[SpitShine_PL]

It's kinda the other way in my case. Someone, before my ownership, replaced the factory installed ZW7 Nivos on my Burb with some regular shocks. It rides alright, although the rear is a bit lifted, giving a bit of a forward rake; unless its normal (the torsion spring height adjustment is not set to be extremely low).
I cannot say if the ZW7 coil springs were replaced with something non-ZW7, I'd need to look for tags or other markings on them, if any are present or have survived.
Do the ZW7 springs for the Nivos look distinctively different, or do they only have a Nivo-specific performance?

 

[azswiss]

Do the ZW7 springs for the Nivos look distinctively different, or do they only have a Nivo-specific performance?

The spring rates are likely different but as to whether they look different, I do not know.