Cadillac Owners Forum banner

1 - 10 of 10 Posts

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #1
H&R springs, KYB struts and upper front strut mounts installed

A few things to mention

- The bottom of the front H&R spring did not fit into the strut perch.
-The inner dia. of the spring was too small of the strut perch.
  • I cut one coil of the bottom so it could sit into the strut perfectly.
  • The diameter of replacement KYB strut for the rear was way small than original. I kept my original rear struts and just installed the H&R in the rear
  • I had forgot to remove the front bump stop, so the initial test drive after the installation was not good. No suspension travel in the front
  • Came back and removed the bump stops and that’s where I ended the day
 

Attachments

·
Registered
2007 CTS Non-V
Joined
·
128 Posts

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #3
Back to the drawing board. With the front bump stops removed, now the front struts are bottoming out. Some keys points

  • Unloaded empty strut measure 25.50”
  • Maximum compression stroke of the strut rod measure 5.25”
  • I push the rod into the strut (took a good amount of force) to compress and measure
  • Loaded strut assembly measures 25.50”
  • Due to the shorter spring height, I did not have to compress the H&R spring to install/remove.
  • With the strut assembly installed, jack stand under frame and floor jack under lower control arm. I got 5” of compression before weight of chassis lifted of jack stand
  • So that confirms why the strut it bottoming out. It only has 1/2” travel, no bueno
 

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #4
It’s a common fact. When lowering some vehicles with coil springs, it’s ideal to use drop shocks/struts with lowering coils.

The length of the OEM shock/strut is not designed for shorter springs.

I think I figured out a way to make our OEM strut a drop strut. I need to take one more measurement to check my hypothesis 😁
 

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #6
Laying in bed quarantine style got my wheels turning. So I’m curious how this is going to end 😁
 

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #7
If the drop spring is causing the strut to bottom out. Meaning the strut has compressed almost completely at right height. Which is a common problem with short compression OEM struts/shocks when using drop coil springs.

So how can we increase the OEM strut compression stroke with drop coil springs?

What you think about this theory? Take a look at the two pics above. The pic of the strut rod and upper strut mount assembly. The upper strut mount assembly rest on the shoulder of the rod below the threads.

Since the upper and lower strut mount location is fixed and does not move. If the shoulder is lowered by X amount, theoretically the strut rod should be raise X amount in the strut assembly? Which should decrease the possibility of the strut bottoming out.

What do you think of that theory?
 

·
Registered
2007 CTS Non-V
Joined
·
128 Posts
Discussion Starter #10
What are you referring to as a “kit” ?
The springs and struts were purchase separately.
 
1 - 10 of 10 Posts
Top