exactly ^

It sounds crazy, I know.

But one time when I bent a tie tod on my Z at an event, the slip and vdc lights were on even when I was going straight.

Not sure of your experience with different types of LSD but an LSD requires constant resistance or clutch or friction materials would wear out. The bad alignment could be a culprit in this case.

I know. I wasn't planning on driving around joy riding, I set up the first appointment with the shop and it just happened to be monday morning. But I still don't know how I get a knocking or clunking noise under accel/brake cause my alignment is off?

Like I said, before I do anything, first thing is alignment tomorrow morning. I'll report tomorrow afternoon.
John

I'm not gonna go along with the alignment comment quite yet, but it wouldn't be a bad idea to take it to the shop and ask if they will look around for prior to the alignment. To me, it would just suck to do an alignment and then find out you put something on incorrectly and have to spend another $80-100 on a second alignment. I would say check all the easy clunking issues first...
-Pillow Ball monut nut
-Sway Bars (sometime people mix up the sway bar nuts with the arm/shock nut and they dont tighten properly)
-Locking perches on coilovers (I've had that knock before) Sometimes they loosen up enough to slap together, for me it was the shock height adjustment lock
-Check for missing tools (yeah, silly as it sounds) If you're getting a sliding clunk on acceleration and braking maybe you forgot a tool somewhere.

If these don't do it, see a professional. They may have to re-do the job to find the error or fault.

Yeah, that first alignment not working and having to do another one is a risk I have to take. The shop I'm taking it to lifts the car up for the alignment on the rack anyways, so I can go under and double check everything.

I'll try to take off the rear coils and see whats up with the pillowball mounts and spring perches. They were all on super tight and no play whatsoever on them. I tightened the locking perches too, no movement at all. I don't have missing tools. I borrowed specifically 2 wrenches, 5 sockets, torque wrench, and 1/2" to 3/8" conversion and I returned them all the same. And I don't think the tool would only make a sound going over 30 and turning instead of driving straight or something?
John

And again, I'm 99% sure everything is super tight. Under the car I double and tripled checked all my work. No play whatsoever in the sway bar, all 4 adjustable arms, shocks on both sides. Nothing. I hope alignment and new tires can make it at least drivable. I guess best thing I can do is wait and see what's going on under the car on the alignment rack tomorrow. Before that, I will mount tires in the rear. So when the rear is jacked up, I will get under and tighten spring perches, will check pillowball mount for being loose, will check endlinks, etc.

Can it just be the stock endlinks can't handle how stiff the rear end is and they keep making knocking and clunking noises?

I'd doublecheck those to, and remember they will have different load on them depending on the arms' position. So check them when you know they are unloaded.

Ok. I know the endlinks are in the right place and they are both super tight. But the endlink has a little rubber bushing on the bottom of it, that rubber bushing allows the sway bar to have some sort of play right? That's how stock endlinks are? Or should there be no play whatsoever?

I tightened it and it's like the threads on the endlink stop, and then there is a black bushing. That's the piece I'm wondering that can cause the car to clunk when I accel hard or brake suddenly, I'm sure the cars torque can cause the sway bar to snap back or forward and hit the exhaust or something else down there. Does that even make sense? Or not really?

A binding endlink is possible, but your drop is not significant enough to cause that. I have installed coilovers on a g35 slammed and the endlinks were not binding. E-diagnosis is always difficult. I would love to have a ride in your car if I were nearby!

I suggest finding a performance shop specialized in performance suspension components. A regular alignment shop down the block may not have the knowledge to diagnose your car.

They aren't just an alignment shop, they also do suspension. And from what I hear, they are one of the best/friendliest and honest shops in the Bay Area. If nothing works. Same day I'll stop by Z Car Garage which is a local Z/G shop and ask them if they can come for a quick ride along to diagnose the car. Now it's just time to play the waiting game.
John

Sounds like you are set man.

Got the tires mounted and balanced this morning and then headed straight to Alignment. Noise was gone after alignment. Car's rear end is very stiff and once again, no more problems. Thanks for all the help. I knew I didn't install something wrong lol.
John

That's good news!

Suspension noises can occur for no apparent reasons, at least not that we can visually see. When I eventually get a similar setup as you, I wouldn't be worried. I was a little concerned at first ;)

Yeah. Great news actually. I was worried, but the car runs like a champ now. Was so smooth on the highway ride home. I get the occasional squeaking noise from the rear coilovers going over some bumps or slowly going in/out of a steep driveway. Some grease should take care of that.
John

Sorry to bring back a old thread but I might be having the same problem.. OP did the problem reoccur after in the future?

I have the same coilovers same toe arms and ichiba camber arms.. I'm getting a knock sound from the passenger side rear.. I checked and everything seems tight.. I;ve had the parts on for about 3 weeks. it got aligned a day after the install. but the problem started occurring about 5 days ago.. Its under steering to at slow speeds and rolling at a few miles per house on a slightly bumpy road. I try juking the car right to left hard and moderate speeds but no issue there.. any idea peps?:icon8: