dcher

My 2015 Z07 has 22K miles on it. After buying it I lowered it in front and rear. The rear required cutting the stock lowering bolts due to the rear springs on the Z07. Over the past 4K miles I have noticed a loud clinking noise when I hit a bump or go around a tight turn and it sounds like its coming from the lowering bolts. Has anyone experienced this sort of thing after cutting their lowering bolts on the Z07? Is there a decent lowering bolt for the rear of this car. The front lowering bolts did not require cutting and are not making the noise.

JackTripper

The rubber most likely wore out or split on the bolt. Have you inspected the bolt?

dcher

I am about to get her up on the hoist. I think you may be correct regarding the rubber wear. Is there a way to correct this with my existing bolt? I presume I will need to replace which will require realignment?

foreverfuelie

Phadt makes “articulated” replacement bolts that allow you to drop further and keep the “pad” aligned with the lower control arm. But yes, you will need to re-align the rear after the change.

dcher

Will these work on the rear of the Z07?

Can one buy only two rather than four?

foreverfuelie

dcher, they fit but will still not lower much beyond your cut down stockers. Z07’s like ours have significantly stiffer springing than a regular Z06. The spring rate is what limits that travel more than anything else. The adjustable Pfadt bolts will get you about 1/4” more than the cut down stockers and they are (or were when I bought them) sold only in a set of four.

dcher

Thanks, I just ordered a set. Will install and then re-align. Thanks

Ltrain925

You need lg drop spindles on a z07, your going to have a pretty rough ride

dcher

I agree these would be ideal. However, they run 3K for the set which is more than I want to spend. Given that I have been using cut factory lowering bolts and the ride is quite good, the Pfadt bolts at $200 for the set should be OK with me.

dcher

How big a deal is it to install these? Is it just a matter of hoisting the car and unscrewing the stock bolts and replacing them with the Pfadt ones? How much time will this likely require. With that said I understand the car will also need to be re-aligned.

cyi1

Hey, if you want to split the cost, I'll buy 2 from you.

I also need 2 for my Z07 rear.

foreverfuelie

There is a thread somewhere that describes the process but the “Readers Digest” version is, there is insufficient room to back the bolts all the way out of the spring. So, the spring (and other components attached) needs to be unbolted and “tipped” forward or back (don’t remember which) to remove and replace. That disturbs the camber adjustments, hence the need for re-alignment. Hope that helps.