Non-adjustable Bilsteins or Koni retrofit?

DickRasmussen · **Posted:** Sun Aug 01, 2010 5:43 pm

I guess they were watching the World Cup and got upset when their team lost in the final. :cry:

JamesMilko · **Posted:** Sun Aug 01, 2010 7:22 pm

Wow I can't believe you're having this many issues with them. I've had them on the 3800lb GTO for over a year now without any problems. My fronts are inserts as well, no idea what other platforms use the same ones.

JamesShort · **Posted:** Sun Aug 01, 2010 9:16 pm

JamesMilko wrote:

Wow I can't believe you're having this many issues with them. I've had them on the 3800lb GTO for over a year now without any problems. My fronts are inserts as well, no idea what other platforms use the same ones.

I'm close to returning them and requesting a $190 check for the cost of housings and new rear top hats

. But who knows Lee may surprise me tomorrow.

James, I hope it's ok if I hold onto your compressors for a bit longer....they are very helpful in this ordeal

.

JamesMilko · **Posted:** Mon Aug 02, 2010 8:58 am

No problem. If you just want to hang on to them till an AX that's fine as well. I'm (hopefully) done with suspension work for the season.

JamesShort · **Posted:** Tue Aug 03, 2010 9:45 am

What do you guys think, does this seat look perpendicular to the axis of the damper shaft:

This is what I think is happening (exaggerated):

My coworker rode in the hatch of the car with his fingers on the end of the damper shaft and he said when I hit the bumps that recreated the issue that the end of the damper is definitely vibrating at a difference frequency than the non rattling side.

JamesShort · **Posted:** Tue Aug 03, 2010 5:11 pm

Well, let's see....I've taken the driver and passenger sides apart once each and put them back together with new shocks to begin with. They can be free since that's the price you pay doing the install yourself.

Since then I took the passenger side apart twice debugging the rattle. Then both sides one more time to swap assemblies (this time did not include a break down of the spring, damper, topmount). Then when the noise followed, I took that corner apart 4 more times. I'd say I have at least 13 hours of sweat and busted knuckles and pissed off wife for wasting the whole weekend (she started thinking I was f-ing my car up and that I should pay to get someone else to fix it).

Well, I just got done redrilling the top mount on the rattling side to 12.3mm just in case my initial drill was not coaxial to the damper shaft leaving it off kilter and I put a rubber gasket in there. Noise still there.

So the only thing I could think of is maybe that top mount had internally separated (the rubber isolation peeling from the stamped steel). So I took both sides off, and took the spring/top mount off each side and was going to swap ONLY the mounts. Well since this has been the first time that I've had the dampers both off the car at the same time, I did the hand test (which Lee said is worthless since human hands can't move a piston but a 1/2 in/s or so.

Sure as hell enough the bad sides damper had NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO bump damping whatsoever. The relationship 'force is proportional to velocity' did not apply on this damper at all. The other damper had orders of magnitude more bump resistance.

Oddly enough the rebound damping on the 'bad' damper is spot on! WTF?

So my thought was that with high frequency inputs the suspension would compress so violently fast and then the rebound kicks in so abruptly that it was causing something back there that wouldn't vibrate otherwise to vibrate/rattle (even though I could replicate with the spare, tools etc out of the car). Just some sort of very odd transient behavior with high piston speeds.

Well Lee says this violates all that he knows about dampers, but I'm sending them in tomorrow.

Jason Mauldin · **Posted:** Tue Aug 03, 2010 5:25 pm

are the rears a shock or a strut?

JamesShort · **Posted:** Tue Aug 03, 2010 5:48 pm

Jason Mauldin wrote:

are the rears a shock or a strut?

Shock.

Lee and my wife had me convinced at one point yesterday that it was a install error on my part.

Well I just installed the springs to my OE shocks (in about 35 minutes....I'm getting fast

).

Car sounds perfect!

It is blowing my mind that I got 3 out of 4 bad shocks and I'm sending the 'good' one in as Steve Carter suggests. I want the bad one broken down, the issue figured out, rebuilt and the same done to the other even if it dynos fine. I also want a dyno of both shocks when they send them back to me.

MarcusMcRae · **Posted:** Tue Aug 03, 2010 6:00 pm

Wow. That thing is definitely off. It's a shame you had to mess up your strut mounts.

You definitely have a lot of patience. :shock:

JamesShort · **Posted:** Tue Aug 03, 2010 6:05 pm

MarcusMcRae wrote:

Wow. That thing is definitely off. It's a shame you had to mess up your strut mounts.

You definitely have a lot of patience. :shock:

Yes.....as much as I'd love to just return everything and get the Bilsteins, even getting my money back I'd be out:

$20 drill bits
$98 two new OEM non drilled top mounts
$100 donor struts
$25 pipe cutters
$900 diagnostic labor (10+ hours.....ok this is where you can see maybe I'm not that patient

).

Jason Mauldin · **Posted:** Tue Aug 03, 2010 6:21 pm

JamesShort wrote:

Jason Mauldin wrote:

are the rears a shock or a strut?

Shock.

Lee had me convinced at one point yesterday that it was a install error on my part.

I've felt your pain....
:roll:

Again, good luck getting them fixed.

JamesShort · **Posted:** Tue Aug 03, 2010 9:18 pm

http://www.youtube.com/watch?v=4HH-EI7U_2Q

It's pretty night and day, even visually.

Steven Carter · **Posted:** Tue Aug 03, 2010 10:12 pm

That shock done blowed up. Hard for Koni to fight that-- Hope it gets resolved soon.

JamesShort · **Posted:** Thu Aug 05, 2010 10:01 am

Wow, I have someone in Greensboro that is going to let me 'borrow' his rear shocks! He said he doesn't want to spend money to have them installed if they are going to fail, so worst case I expose the failure for him, give them back and he gets to go through warranty with no sweat of money off his back. Best case, they work out and I give him my new ones when they come in October.

There is no S/N on the invoice or shock, so future issues should not be a problem.

JamesShort · **Posted:** Thu Aug 12, 2010 9:14 am

For those who care...here is the new scoop.

Koni-na has received all my bad shocks/inserts.

The leaking insert was due to a poorly seated o ring internally.

The 1/2 turn insert is an anomaly. Koni-na is sending it to Holland for problem determination.

The rear shock with no bump damping was due to a small burr that 'clogged' a compression valve such that it could never fully close.

All 3 bad shocks had different problems and all 3 are *NOT* pervasive to the whole first production run.

Sooooooo I just have absolutely horrible bad luck I suppose. FML.

FYI, the picture above of the non perpendicularly threads must be an illusion due to the threads. They say it is perfectly square.

THSCC Forums

Non-adjustable Bilsteins or Koni retrofit?

Who is online