Zr2 front suspension

Chuck FB · February 27

15 minutes ago, UTGOZER said:

Boom! Done!!

It turned out just as I hoped.

Again, thank you to all that have contributed to this thread.

It would be interesting to compare your suspension height measurements compared to stock. I realize the GMC fender is slightly different than the Chev so one has to keep that in mind when comparing the two brands. Would you be able to find a flat area to park ( sometimes harder to find than one would think ) and measure from the underside of all four plastic fender moldings to the center of the hubs. You may have done a certain amount of that already to set the front end even from side to side. Measuring this way takes any tire size or tire inflation pressure out of the equation so its the perfect method to compare one truck to the next for suspension heights.

The other part I am curious of is did you measure your droop distance, if not and had a chance sometime to lift the front of the truck until the front tires are just off the cement and measure in the same way as I described. Also when the front tires are off the ground, is it the upper control arm that stops the downward travel by going against the frame stop or the shocks extending to their full length.

UTGOZER · February 27

I'll bet it took me 15-18 hours. One full weekend day and a few nights after work.

Having a second set of hands to grab tools and during re-assembly was super helpful.

I used 6 ton Jack Stands that start at 18"+/- tall. I believe my Floor Jack is 6 ton too. Second set of jack stands came in handy to hold the Lower Control Arm up during re-assembly.

There were certianly situations like torqueing the Lower Control Arms bolts where I wished the truck was further off the ground.

Tips while they are still fresh:

Start by getting the axle nut off then disconnect the steering tie rod so you can turn the Knuckle back and forth for easier access the Brake Caliper Bracket bolts and Hub bolts. With the axle nut off you can push the stub axle in to give more access to the hub bolts.

The most tedious part is certainly the Diff Carrier Brackets. I supported the diff with a floor jack under the pumpkin, and started by loosening the 4 bolts that go up through the brackets to the frame. I swapped the passenger side bracket out first and left everything on that side very loose while I moved over to the drivers side. Lower the drivers side down some to access the third bolt on top of that bracket and it helps to have the diff lowered down to get the drivers side bracket out.

Take bunch of pictures of the bolts that go through the Upper Control Arms to aid you during re-assembly. I installed the drivers side UCA bolts backwards/upside down and it went right together like it was correct. Oops...

OS RR · February 28

Did you have to reset your torsion bars? I seem to recall they go right back where they were with the ZR2 stuff.

essubilt · April 2

So it seems like the working consensus is that the 84745473 and 84745475 GM torsion bars are the equivalent to the Cognito Comfort Ride components.

This has me wondering if the Comfort Ride leaf springs are also just rebrand OEM units as well. Was wondering if any of the fine GM part savvy folks here have a thought as to what GM leafs are equivalent to the Cognito leafs.

kylant · April 3

17 hours ago, essubilt said:

So it seems like the working consensus is that the 84745473 and 84745475 GM torsion bars are the equivalent to the Cognito Comfort Ride components.

This has me wondering if the Comfort Ride leaf springs are also just rebrand OEM units as well. Was wondering if any of the fine GM part savvy folks here have a thought as to what GM leafs are equivalent to the Cognito leafs.

cognito leafs are made by deaver