Zr2 front suspension

Epsilon Plus · January 29

Trail Boss info out. Super lame. Z-71 with black painted bumpers and red tow hooks. That's it. No ZR2 lift. So they're not stock piling the knuckles for it at least.

Super lame announcement from GM. Should have been ZR2 lift with Ranchos and 33s.

Epsilon Plus · January 30

Knuckles are ordered but still "In Process". These are hard parts to find. I asked the guy at a dealer parts counter when I was there picking up an accessory if he had any deeper look at the parts system and he mentioned availability around mid February. If my parts ship/arrive, I'll update.

215robert · January 31

X2 informed on mid February!

Epsilon Plus · February 6

Knuckles are available to order and are shipping. My passenger one shipped and the driver is expected the week of 02/12

215robert · February 10

Knuckles arrived! In the process of measuring them to see if there's any height difference...

215robert · February 10

Easiest point to measure with truck complete, appears zr2 knuckle to be .5 longer

215robert · February 10

Also from lower control arm on truck this measurement is on 1" shorter!

chevy2tuff2006 · February 10

Skid plate 85637479 is ordered. Thanks for all the info here. My truck didn't come with any skid plates and I have a 3" BDS lift on it now and hopefully this plate will work great since the diff has been dropped.

Epsilon Plus · February 15

Got the whole shebang now. Need to get a torsion bar tool and look up torque specs on all the bolts. Hopefully, none of them are torque-to-yield and can be re-used.

Epsilon Plus · February 18

On 2/10/2024 at 10:00 AM, 215robert said:

Also from lower control arm on truck this measurement is on 1" shorter!

When are you putting your stuff on? My torsion bar tool gets here Monday. I'm going to buy the GM 3 day subscription to the service manuals and try to copy down any torque specs or procedural info I find. The differential brackets seem to be the worst part. Might do those with all the control arms, hubs and knuckles off for access and less weight to support. After I get all the parts on I'm putting it on my new Alaskan 18s with likely 37x11.5 Nittos. Going to be a completely different truck.

215robert · February 18

Also from lower control arm on truck this measurement is on 1"

215robert · February 18

Hopefully next week, I agree, diff drops will be hardest part...

Would much appreciate those torque values!

SMiller · February 21

My question is can we simply swap out the upper control arms? Seems like a great option for those looking to simply crank the torsion bars while correcting the ball joint angle.

Would be interesting to compare a stock, ZR2, and a Cognito/Kryptonite.

I am used to using aftermarket A-arms and front diff spacers, seems the GM version actually lowers the entire cradle.

Crazy GM went through all this work for 1.5in as the rest of the height comes from the taller tires.

SMiller · February 26

Drove a ATX4 today and was kinda let down, shocks were stiffer then stock, ride was unimpressive, I was expecting more of a Fox shock feel which each smaller bumps and is a smooth ride, these shocks are stiffer then stock, I'm guessing they eat BIG bumps better but day to day a huge let down.

Really wanted to order the upper control arms but I see the mount the brake lines on them, guessing I will stick with stock or go aftermarket upper control arms.

Epsilon Plus · February 27

Brake lines don't look to me like it's going to be an issue. Previous looks mounted on the knuckle but it's a flex hose and looks easy enough to work around.

As far as the shocks I learned the same going away from Rancho. It's really not the shocks fault, it's the gargantuan spring rate. 3,500 pound leaf sprung payloads and soft ride don't compute. When I had a rear Bilstein in for warranty, I drove around for a few weeks with no shock on one side and there was ZERO difference. I even bounded it off of speed bumps and such to try and get the back to dance but it was rigid like I had a bar welded in place of the shock.

The only way you're going to feel damping on a GM HD truck is under decent payload or towing heavy (>10k lbs). Otherwise, it's covered wagon time.