Weird rubbing mark with aftermarket front sway bar endlinks

[BishamontenZC6]

Hi all,

I'm facing something new with my 2014 BRZ, that's been running ST STX coilovers flawlessly for more than 15'000km with a modest 20mm drop over stock, 225/45-17 on 17x8 ET35 rims, and -1.8 deg negative camber front. There has been NO change to any of that before the following problem showed up.

My passenger side (right) front sway bar endlink decided to start giving up after 160'000km a few weeks ago. It wasn't making any noise or clunk but the boot was punctured and all the grease had come out. I therefore decided to replace the front endlinks pair. As the OEM ones were on backorder at my usual dealer, I decided to go the faster, easier (and risky) way and ordered a pair of TC5884 Delphi endlinks on Rockauto :



Those are supposed to be identical to the OEM, non adjustable ones.

Installation went fine and I drove the past 2 weeks normally. Yesterday, while checking the suspension to make sure that they were still torqued properly, I noticed a weird contact scratch on the inside of the passenger side wheel well, that wasn't there before (100% sure as I took pictures before installing the Delphis) :





I don't understand where it comes from because I've never had a single scratch, noise or whatever in 15'000km with the OEM ones, and even with the Delphis I didn't get any clunk or knocking noise in the past weeks. I also tried to move the steering in all directions, full lock left/right, different suspension compression and it doesn't seem to touch in any case.

Could it be that the Delphis are a little bit thicker, or the nuts longer ?

Is there something else I'm not thinking about ? i might end up ordering OEM ones eventually but I would like to understand what's going on instead of chasing ghosts.

[NoHaveMSG]

Need shorter endlinks. What’s your sway bar looking like with the car sitting.

[BishamontenZC6]

This is while sitting in the pictures. But no, I was expecting that answer but you don't need shorter endlinks with the modest drop that I have. On top of that, as I wrote, I had been running the OEM ones that are the same length for 15'000km without a single problem (rubbing, clunk, etc.). So it's very unlikely to be a length problem.

[Racecomp Engineering]

Is there a mark on the back side of the endlink?

- Andrew

[BishamontenZC6]

I checked the inside side of the endlink head and it doesn't look like there's any mark. At the same time, it looks like the scratch on the wheel well is superficial, it only scratched the kind of "insulation" and dirt outer layer, the metal underneath is still has paint.

The scratch also is at the level of the head when the car is on jacks and the suspension hanging, not at any point when the suspension under load.

[EndlessAzure]

Probably endlink collision.


While the car is on the ground, check the endlink clearance at max steering lock and evaluate the clearance for an idea, but that's not the whole story.


The endlinks undergo min clearance at max steering lock plus when they are differentially loaded (like when you are angled for a steep driveway, then drive onto it loading one side of the suspension first).

[NoHaveMSG]

Originally Posted by BishamontenZC6

This is while sitting in the pictures. But no, I was expecting that answer but you don't need shorter endlinks with the modest drop that I have. On top of that, as I wrote, I had been running the OEM ones that are the same length for 15'000km without a single problem (rubbing, clunk, etc.). So it's very unlikely to be a length problem.

Guess I should look at the picture. Mine clears with white line end links and a ton of negative camber at the top hat. Couple others I tried were no good and would hit.

[cmiovino]

Mine did this. I have -4 degrees of camber up front and this is on a KW based coilover (which it looks like yours are too).

I ended up getting some basic, adjustable endlinks. You want the heads to be slimmed down. They call this "low profile". It helps not make contact there with loads of camber.

The second thing you really want is to have adjustable length endlinks. First, you want the swaybar to sit properly and not to have the endlinks or the bar hit other things like the lower control arm. The other huge benefit is taking out pretension on the bar. I used to run the long stock ones and just jam them in there, tighten it down, and then put the car on the ground and the car would seem to understeer even though it was only a 10mm bar. I got the new endlinks, adjusted it properly, the tightened everything down when the wheels were on the ground instead and holy cow did the car just work better. No understeer and it just stuck.

So yeah, you'll need adjustable low profile endlinks to avoid the contact and have better handling. When you put coilovers on, the stock ones or anything stock-ish length just become too long.

[BishamontenZC6]

Many thanks for your insight.

As I mentionned before, there is no need for shorter nor adjustable endlinks with -20mm drop over stock, which is confirmed by the tangible and measurable fact that I had ZERO problem or noise with the exact same setup and stock endlinks for 15'000km prior to replacing them. My BRZ rides beautifully, zero understeer, steering is as direct as it comes (with other supporting mods). To me it was absolutely perfect and I'm used to Lotus, Noble and TVR steerings as references.

In your case, you have 4 degrees negative camber which changes quite a lot compared to what I have (and probably much more drop too), and understandably causes some rubbing on the wheel well. This is well known and documented, and the solution is indeed to put shorter/adjustable (for the drop) AND slimmer (for the negative camber) endlinks. I'm in neither of those cases fortunately as my setup isn't as extreme. Some people even relocate the connection on the lower control arm instead of the strut to get rid of the problem with a lot of camber.

I ended up ordering a set of new OEM endlinks last week, they should hopefully arrive in the next days. After taking measurements everywhere, I'm pretty sure my problem is circled down to 2 things :

1) The Delphi endlinks heads are bigger than the OEM ones by a couple mm both in diameter and thickness. This causes occasional light rubbing of the upper head (connecting the strut) on the wheel well on the right side.

2) The bolts on the Delphi are longer than the OEM's by 5-10mm, which causes light rubbing of the lower bolt (connecting the sway bar) on the lower control arm on the left side. I had not noticed that the first time I checked under the car.

I can't confirm that but I think that those 2 different problems on each side cause the sway bar to slightly slide left and right, making the rubbings more pronounced depending on the particularity of the roads I drive.

All this leads me to think that in no circumstance should those Delphi links be used as long as you ride anything else than stock height and alignement. I'll post the confirmation and actual measurement when everything will be solved.

[BishamontenZC6]

Here I am with the final solution of my problem.

Received the stock endlinks and installed them flawlessly. They were much easier to install than the Delphis, didn't take more than 40 minutes including lifting the car, removing the wheels, putting everything back and tidying up the tools.

So my diagnostic was correct, there are slight dimension differences between OEM and Delphi endlinks on 2 critical spots if you run a slightly lowered BRZ.



Based on the references on the picture above :

A : 2mm longer than OEM
B : 5mm longer than OEM
C : Same diameter as OEM (I was wrong on that)

Longer A probably caused the slight scratch on the wheel well, in a particular condition driving condition I can't remember. Seeing that the scratch only removed the protective layer and didn't damage the paint under it, it's a sign that it was a one time only scratch and it didn't go deeper than surface. In that case, the explanation of the 2mm longer endlink head is valid. Sometimes 2mm is all it takes to remove clearance.

Longer B definitely caused the scratch mark on the left lower control arm. This was the easy one to diagnose. The OEM bolt being 5mm shorter allows a much better clearance, with absolutely no rubbing possible.

So there is it. Bottomline is, do not cheap out and go for aftermarket "OEM style" endlinks if your car is lowered unless it's been proven that those are OK. Even though they are supposed to be direct replacement and are most probably absolutely fine with a 100% stock suspension setup, my experience shows that some tiny difference can cause some really annoying problems, plus loss of time and money in other cases.