Raising them would increase the preload and cause more tension.

 

I had 40K km on my coupe before I sold it. About 20k of that was with stillen sways with stock bushings. I had no issue.

 

Pretty sure all they were trying to tell you is that the collars could be loose. It's REALLY easy to tell. There's one on the shock, and two on the spring perch. Crap ***** I'll try to make a diagram when I get a real computer in front of me.

 

Thats what I think you need to raise the collars(slightly raising the ride height) that would put a little more tension on the springs.

 

It's DEFINITELY nailed down to an area directly around the back driver seat, behind it right in the vicinity of the adjustment **** for the coilovers. A friend sat in the back to localize it and said if she could put a finger on it it was right where the back seat meets the B pillar.

I do love a good diagram though- so if that's possible I'll be all eyes...

From BC:
When we first released the G37's there was something in the strut tubes that was emitting a rattle, but after figuring out what it was and sending out new parts to the owners with rattly shocks we never had a problem again. I had one other gentlemen contact me about a rattle and he sent me the same link. I asked him to check the preload on his springs and sure enough that was the problem. The customers that did have rattles had them from the moment they were installed. Being that yours happened after a few thousand miles leads me to believe it is most likely insufficient preload on the rear springs

What you can try and do is jack up the car and add more preload to the rear springs. There are two lock rings on top of the spring (spring perch). The smaller one can be broken lose of the larger one, once that is done you can rotate the larger one and add about another 1/4" of load to the spring, if that doesn't fix it add another 1/4". On multi-link rear suspensions you can run considerably more preload on the spring then on the actual spring over strut combo like the front.

So that's where I'm at with that- it seems to gel with what you guys are saying too- and that's as easy as taking the back tire off and twisting some wrenches. I guess where I get lost is the tensioning adding or taking away from ride height- which I'm under the impression it won't if adjusting the one on the spring perch.

I have to look at the TSB- maybe just take the back seat out and look around at what's going on under there. With it being isolated to one side and SO CLOSE to the top of the seat- makes me doubt on the spring tension. Then again- I have a hard time visualizing exactly what's going on at the top end of that arrangement where it meets the car...

Anyways thanks again for the help guys.

 

^^ Yes indeed Gord, didnt mean to undermine you.

What springrates do you have? I have ZERO preload in the back and they dont creak (I also have BC's).

 

Sorry- how do I even look at that? You talking the adjustments? I'm 10F and 12R. I tried going with 0F 0R and it was quite a pleasing ride even down low. I thought if I tightentend things up it might help but it hasn't.

And to better describe the sound- I guess I was calling it creaking because it's that annoying but my friend described it more like metal bumping against glass, or metal bumping plastic...

Does that help?

 

You might have to get someone who knows coils to look at it/take a ride. That ain't me, unfortunately.

 

^+1

I should have paid more attention to thread to see what we were talking about in the first place.

 

Also try asking Karma since he runs BC coils.

 

Sorry Rbull... kind of drifted off topic. Became my personal problem solving thread.

 

Here are the photos of the arrangment. My understanding is that they want me to tension up the spring on the spring perch about a quarter of an inch. To do this, they say to break the small locking nut free and add tension, then lock it back up. Though it's reversely intuitive, I take it that the adjustmet needs to be made upwards to push down on the spring as Gord had mentioned.

 

Not so much talking about damper adjustment. I set mine in the middle and havnt touched them since hah.

I was referring to springrates, like the stiffness of the springs. You probably just have the BC factory rates of 10kg front, 8kg rear. I ordered a 12/10 combo due to my overly agressive driving. All of that aside, none of that will matter ASIDE from where your collars will be on the perch in relevance to your drop.

Now about that diagram...

 

Make sure the collar on the shock is tight, and on the spring perch (put one wrench on to tighten, and the other in the opposing direction to hold everything in place, naturally).

Now, I DOUBT that spring tension is an issue, as the collars on my cars rear perches are all the way at the top, and if I grab onto the spring I cant move it by hand. The simplest thing you can do is just that, grab onto the spring, and if it slides around on the lower A arm (or whatever its called on these stupid cars) then a light of spring tension MIGHT be causing your noise.

Keep in mind, if you do add some preload in there, the *** end of your car will be raised.

Uhhhhhhhhh. Now what?

 

Thanks for the diagram! I'm not sure it's going to help me- I'm having a hard time getting my head around these really basic principles!

Okay so basically I just adjusted the collars for the spring so they actually went up higher (towards the car)... about a quarter of an inch.


I think that actually made it worse. I'm pretty sure that by doing that I actually loosened the tension- I figured it'd twist the actual stem dowards but I don't think it accomplished that

I take it that lower collar actually pushes down on the plate that presses on the spring? And the top one locks it in place?

I know, I'm an idiot! (Edit in: Just actually tightened spring tension 1/4 inch from where it was originally and still no change. I hadn't actually tried the spring by hand because I figured it'd be too stiff- but yes, once I tried it sure enough I could move that mother no problem. So now the question is- where do I get these things looked at around Calgary without going to LSI in RD?)

The sound seems to be coming from the shock tube as it's where that meets the car that the noise seems to be coming from.

I'm going to go reverse what I did and see what that does. Might as well learn something.