Tein Flex Z intermittent lean/sag blown damper?

[FrickingReallySlow]

so this weekend I was doing some twisty roads and suddenly started hearing constant scraping sounds in the back. I stopped and looked to find that the driver side rear was lower than the passenger side rear by about 3/4 inch.

I have Tein Flex Z (VCQ55-U1931) and already lowered by 1" (my fender to hub is 13"3/16). Just did an alignment in March (sheet attached)

I could see the spring was more compressed on the driver side than the passenger (see pictures attached). After letting the car sit a bit, I raised the rear and let the suspension droop a bit and after lowering back down the suspension went back to roughly to its original height.

Has anyone experience something like this? I'm gonna take it to a shop but most likely I'm thinking the dampers are bad . I've only had the Teins for <12K miles with no tracking/autox so kinda disappointed they didn't last very long. Also the damping adjustment I had was right in the middle so not too harsh or soft

[EndlessAzure]

@FrickingReallySlow I don't think I would attribute change in static ride height to be a symptom of a bad shock. Bad shocks usually manifest in dynamic environments when your suspension needs dampening (think excessive bouncing or always slamming onto the bump stops). It's the job of the springs to hold your ride height.


Before the coilovers were first installed, did you verify that the collars positions/preload were set appropriately? How long was it between when you first installed the coilovers to when you got your car aligned and height adjusted? Did you check the preload and height adjustment collars to see if they came loose?


Another possibility is that your shock rod is bent, making it unable to return to the neutral position easily. Have you incurred any sharp impacts on that corner of the vehicle? Any signs of leaking shock fluid?

[FrickingReallySlow]

thx for the reply. These coilovers were installed in 2019 by the previous owner so have been on the car for quite a while. I made a slight height adjustment in august last year when I noticed they weren't all "exactly" at the same height (hub to fender). got an alignment this year since I crushed my back driver side quarter panel in a parking lot (going slowly no frame damage). As you can see the alignment wasn't too bad.

I've definitely gone over big bumps on the highway where it felt like it reverberate through the whole car so that might be a cause too as you've mentioned but it should impact all 4 corners since these bumps here in SF highways are discontinuities in sections across all lanes and it felt at times like it hit the bump stop. I've set the damping to right at the center and only dropped 1" on stock 17" wheels so didn't think these bumps would do much damage. Called Tein to see what they think and they wanted pictures of the coilover from underneath so gonna do that at the shop later this week to look for oil or other anomalies.

its weird that the car would drop in height from just mild sharp turns and then rebound back to normal after decompressing

Originally Posted by EndlessAzure

@FrickingReallySlow I don't think I would attribute change in static ride height to be a symptom of a bad shock. Bad shocks usually manifest in dynamic environments when your suspension needs dampening (think excessive bouncing or always slamming onto the bump stops). It's the job of the springs to hold your ride height.


Before the coilovers were first installed, did you verify that the collars positions/preload were set appropriately? How long was it between when you first installed the coilovers to when you got your car aligned and height adjusted? Did you check the preload and height adjustment collars to see if they came loose?


Another possibility is that your shock rod is bent, making it unable to return to the neutral position easily. Have you incurred any sharp impacts on that corner of the vehicle? Any signs of leaking shock fluid?

[NoHaveMSG]

The locking collar on those will come loose if you don't get them really tight. I'd check that first.

If the damper is blown it will usually oscillate when you hit a bump.

[FrickingReallySlow]

Originally Posted by NoHaveMSG

The locking collar on those will come loose if you don't get them really tight. I'd check that first.

If the damper is blown it will usually oscillate when you hit a bump.

Checked for oil, loose washer at the top and collars. Nothing seems to out of the ordinary at the shop, Also check the surrounding control arm bushings/links etc. Videos of the coilover install in case anyone can help take a look. Sent email to Tein to see if they can respond. since I'm way past 1 year warranty I may just have to just wait 2-3months for a new damper

https://drive.google.com/file/d/1oPi...ew?usp=sharing

https://drive.google.com/file/d/1Qca...ew?usp=sharing

[FrickingReallySlow]

got a response back from Tein. They're saying I need to preload my suspension while I do the install. it "seems" to make sense, I never thought you need to preload suspension during an install

"Please read our blog on applying suspension preload. http://teinusa-blog.com/applying-suspension-preload/. This should clear things up what we mean. This is what seems to be the issue. Your OEM arms had tension from the vehicle being at a higher height and when you lowered it. You did not loosen the lower control are bolts, and add suspension preload. So when you were driving on a twisty road that was enough force to break the tension, and in turn lowered the vehicle. You will be re torquing all locking collars and the top nut to our factory specs in the manual. Please make sure you use the manual to find the torque specs. All specs can be found in the manual on the assembly diagram page."