Good day everyone. My car is a 03 Z06. l have had several now and never had this issue. When l purchased the car it had 168xxx miles and was slammed on the ground with lowering bolts. The shocks appeared to be OE so l replaced them with new C6 Z06 shocks all around. l also just procured some factory length rear lowering bolts and herein lies my problem. So l installed them on both sides with app 4 threads showing above the locknut. Put the car back down on the ground and took for a few mile drive to have the suspension settle. Came back and measured. Now l measured the DS first and was very close to where l wanted it, app 27-3/4" ground to fender lip. l go around to the PS and it was a little over 18, say 18-1/8". Now l didn't expect it to be spot on with the other side as l know thats not it works in the real world. So, no biggie, lift the car and readjust the PS down a bit to match the DS. So l give it nut a full turn, lower car and take it back out for a spin. Come back, remeasure, ZERO difference. Hmpf.... odd l thought. Undaunted l do same procedure again,(every time l adjust l take car for a 5 mile, uneven bumpy drive to remeasure) one full turn on nut, again... ZERO difference. Ok l thought, this time l adjusted to full lower on the stock bolt, just half a thread protruding from the lock nut. Go drive, return, measure again. This time it did in fact lower, but still not to match the 27-3/4 on the passenger side. lt is sitting at about 27-7/8. As l sated at beginning of this thread, l have owned several C5 Z06's and have lowered all of them a little on the factory bolts. l never felt the need to lower more than they would allow. But lve never had one not respond to twisting the lowering bolts/nuts. What the heck could be causing the rear PS to not respond to twisting the lock nut and unloading the mono leaf on that side? So the final result on the bolts are the DS has just a little more than 4 threads showing above the nut, almost 5. The PS has ZERO showing above the nut. What the heck can cause this?!?! Any ideas would be greatly appreciated

 

I'm not an expert on lowering, but that does sound strange. I don't think the issue is the bolt position. If you adjust the position and see no change, I would think it is because the suspension has not settled properly on that side. I would readjust to about 2-3 threads, and then just try giving it some additional time/distance to settle. Maybe an alignment might help. Like I said I'm not an expert.

 

Thank you for reply MW. I kinda thought the same thing so I stopped and let it be yesterday afternoon. I will take it back out this afternoon and measure again. I will post my results after!

 

Best of luck. I hope it solves your problem.

 

Well I got home, hopped into car, went for 5 mile drive, came back and measured. No change 😡

 

Moved to C5 Tech.

 

Dont know for a fact on this or if it may contribute but I have heard the C6 Z shocks are a little taller than the original C5. Maybe some of it?

 

Well l had heard about this possibility before l had purchased the C6 Z06 shocks as l did much research on the matter B4 l pulled the trigger on buying them. l did my own measuring when
l removed mine against the new C6 units. The C6 units were indeed about 1/2 taller. However, this will have zero effect on ride height as the shocks do not determine ride height, the mono leaf does. Unless of course the shocks are binding in some sort of way, which these are not as when l place a jack under the frame and go up, even in the slightest, the shocks allow the
expansion with no binding issues whatsoever. And the opposite is true as well, if l apply pressure to the rear of car, the suspension collapses with zero issues also. What l am going 2do 2day is raise the front end, as it is still super low, and see if that somehow helps level out the back? Wishful thinking l know, but l'm quickly running out of things to try,

 

Also not an expert, but you may want to give that rear leaf a cleaning and very careful visual inspection to make sure it is in good order.

 

Yes, l did that as well. Even though l have never in all my time working on these cars came across a bad one. l thought who knows what the prior owner(s) have done. So l cleaned it very good and inspected for cracks of any kind and found none. l mean, other than the obvious crack or split, can these things even go bad? l have worked at two different Chevrolet dealers combined for over 4 years as a light duty tech and l dont recall ever seeing a failed one, or anyone l knew there replacing one. Unless car was in an accident. But l guess anything is possible. l never have a closed mind