Zr2 front suspension

GMCnewbie · May 11, 2025

9 minutes ago, kylant said:

except for when the unloading tool falls off the crossmember, hits your head, and then you need to go get a few stitches. don't ask me how i know

I came close to having that happen as well. I got lucky and was able to shift my head just before it dropped.

Chuck FB · May 11, 2025

3 minutes ago, GMCnewbie said:

I came close to having that happen as well. I got lucky and was able to shift my head just before it dropped.

Who knew that the old enclosed face street bike helmet kicking around would come in handy ... and the neck brace from same said motorcycle accident, "repurposed" ... just kidding

kylant · May 15, 2025

does anyone have a source for those lower control arm bolts? mine have been on order for a while now, the dealer seems to be having a tough time getting them from GM. Seems like they are an odd size and the aftermarket, like Fastenal, doesn't have them either

thanks

GMCnewbie · May 15, 2025

I've ordered parts from this dealership and had good luck.

https://parts.jakesweeneychevrolet.com/oem-parts/gm-front-lower-control-arm-bolt-11549229

Ive also ordered from these guys too.

https://www.gmpartsdirect.com/oem-parts/gm-front-lower-control-arm-bolt-11549229

My local dealer in Houston wanted $27 per bolt. I had to argue with the parts manager to get the to sell them to me for MSRP.

Good luck!

Epsilon Plus · May 15, 2025

I get all my shipped stuff from GM Parts Direct which is Flow Chevrolet in NC. They have been in the online GM part game since the way back supporting forums like LS1GTO and LS1Tech and I've never heard or had issues with them that weren't resolved. They also seem to consistently have the best or even pricing with the others (TASCA...etc) but unlike the others I think they have a personal watch on their GM inventory system. IE. when the knuckles were unobtainium they were listed as backordered and you couldn't add them to cart. Other GM sites around the web you could. There's actually a rear door crew cab interior piece I'm interested in (84631258) that will show up on other sites but on theirs it says unavailable so I don't even try it anywhere else knowing the order will just bounce back.

LC bolts show available there:

https://www.gmpartsdirect.com/oem-parts/gm-front-lower-control-arm-bolt-11549229

Edited May 15, 2025 by Epsilon Plus

kylant · May 15, 2025

i'll try them. i have had them on order from my dealer and they say they are direct ship. it's been 3 weeks. i called another big online seller and they said they are "backordered"

i have found them for the HD up to 2019, and really the only spec difference I am seeing is they are a touch shorter, like 1/8" shorter. i'll keep bugging my dealer.

i want to do this conversion over memorial weekend

newdude · May 16, 2025

3 hours ago, kylant said:

i'll try them. i have had them on order from my dealer and they say they are direct ship. it's been 3 weeks. i called another big online seller and they said they are "backordered"

i have found them for the HD up to 2019, and really the only spec difference I am seeing is they are a touch shorter, like 1/8" shorter. i'll keep bugging my dealer.

i want to do this conversion over memorial weekend

Those bolts have been on and off backorder for like 3 months now. Took us a while to get some for a truck at work and that was in January/February.

kylant · May 16, 2025

10 minutes ago, newdude said:

Those bolts have been on and off backorder for like 3 months now. Took us a while to get some for a truck at work and that was in January/February.

do you have any connections?

newdude · May 16, 2025

8 hours ago, kylant said:

do you have any connections?

No. Its all dependent on the supplier and has been. They seem to be able to handle production line hardware needs but can't fill service parts regularly.

kylant · May 19, 2025

no bolts in site. I have searched high and low. Dealer is still working on it.
This project is going down this weekend. I have 5 days off.
I ordered some grade 10.9 bolts, washers, and crimp locks, with nearly identical dimensions (just 5 mm shorter) that should be here in the next day or so. at least I will have something. I highly doubt a grade 10.9 M18 will be significantly weaker after 1 use.

I looked at about 6 different lift instructions over the weekend. all of them reuse the factory bolts...

are there any tips/tricks to doing the diff carrier brackets? did you guys lower the diff? remove the cv axles? those look to be the biggest PITA for the swap

thanks

Edited May 19, 2025 by kylant

GMCnewbie · May 19, 2025

1 hour ago, kylant said:

are there any tips/tricks to doing the diff carrier brackets? did you guys lower the diff? remove the cv axles? those look to be the biggest PITA for the swap

They were a massive pain to swap without any tips beforehand. I wasted a lot of time trying to get the old brackets out and then getting the new ones in.

I started my project with the passenger side first and didn't touch anything on the driver's side until I completed the passenger side (with the sole exception of releasing the torsion keys on both per Cognito's instructions.

The easiest way to get the old brackets out and new ones in is to remove the protector plate (mind just went blank on the part name) that covers much of the underside of your truck. Then, loosen the bolts on the other bracket to gain a little extra wiggle space to move the bracket you're working on. If you leave the other side fully mounted, it will be a massive struggle to get the brackets in and out.

The driver side was impossible to remove until I dropped the plate and loosened the passenger side diff carrier bracket. Once I did those two steps, the driver's side bracket easily slid out and the new one went in without any issue. I felt like a complete moron after I got the new bracket in. Seriously. I struggled for more than an hour on the driver's side before I did those extra steps. It was a few extra steps that took maybe 5 mins and made the work soooo much easier.

Good luck!

GMCnewbie · May 19, 2025

The other parts that I wasted a lot of time with (and ultimately replaced) was the stabilizer link bar. GM did us a solid with these pieces of crap. There's a guide plate added to the lower bolt on this bar that is not permanently secured to the bar. I didn't realize this as I was removed the lower nut and was trying to get the bar free from the LCA. Well, the guide plate popped off for me and couldn't get it back on because of how they made it. So I was screwed by my local Chevy stealership into paying nearly double MSRP for a new stabilizer link bar.

I say this just to make sure you're careful with that one part as you disassemble everything. I didn't have an issue with the passenger side. It was the driver's side that gave me all the issues. Be ready to replace if you're unlucky like I was. I wasted a lot of time trying to get the plate back on the bar. Not worth it in the end.

kylant · May 19, 2025

5 hours ago, GMCnewbie said:

They were a massive pain to swap without any tips beforehand. I wasted a lot of time trying to get the old brackets out and then getting the new ones in.

I started my project with the passenger side first and didn't touch anything on the driver's side until I completed the passenger side (with the sole exception of releasing the torsion keys on both per Cognito's instructions.

The easiest way to get the old brackets out and new ones in is to remove the protector plate (mind just went blank on the part name) that covers much of the underside of your truck. Then, loosen the bolts on the other bracket to gain a little extra wiggle space to move the bracket you're working on. If you leave the other side fully mounted, it will be a massive struggle to get the brackets in and out.

The driver side was impossible to remove until I dropped the plate and loosened the passenger side diff carrier bracket. Once I did those two steps, the driver's side bracket easily slid out and the new one went in without any issue. I felt like a complete moron after I got the new bracket in. Seriously. I struggled for more than an hour on the driver's side before I did those extra steps. It was a few extra steps that took maybe 5 mins and made the work soooo much easier.

Good luck!

thanks for the tips. did you remove the cv axles or drop the whole diff at all?

looking at lift install instructions, it looks like it would be so much easier to just drop the diff, but i don't want to do that if i don't need to

i'll pay attention to the endlinks. i really don't think that retainer tab is even needed

GMCnewbie · May 19, 2025

1 hour ago, kylant said:

i'll pay attention to the endlinks. i really don't think that retainer tab is even needed

I believe it is necessary (don't quote me) as I believe that's what prevents the ball joint stud from spinning while you tighten the nut.

1 hour ago, kylant said:

did you remove the cv axles or drop the whole diff at all?

I did not remove the cv axles. I simply loosened the diff carrier bracket bolts on both sides along with removing the skid plate. That will give you an extra inch or so to maneuver with the brackets in and out.