STEVO9000 54 Report post Posted February 12, 2015 Hoping someone can help here! I've just fitted some of the titled coilovers to my 86. Car feels fine, but I'm getting a knocking noise coming from the rear, seems to be both sides. All bolts are tight, top mounts are tight. Turned the shocks to fully soft and seems to make the knocking less noticeable but it's still there. Has anyone else come across this before? Is it just a trait of the coilover itself or should I be looking for something else..... Thanks! Share this post Link to post Share on other sites
Jamie_GRMN 177 Report post Posted February 12, 2015 I have them fitted, and have done for about 8months and no knocking at all, not even after hard sprint sessions or a trackday... How much have you lowered them by? Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 12, 2015 I've not touched the height at all yet Jamie. I'm taking it for alignment and setup on Saturday morning so I was going to have the height adjusted then. I've spoken with the company I bought them from who are kindly querying it with BC tomorrow. Doing some googling though, appears to be a common problem for the tears not necessarily on the gt86 though but quite a few guys on the frs forum have had the same issue. Share this post Link to post Share on other sites
rob275 1817 Report post Posted February 13, 2015 I get a knocking on the rear, i'm on teins though. It's nothing to do with the coilovers as far as i'm aware. Just a creaky panel somewhere Share this post Link to post Share on other sites
GTB 53 Report post Posted February 13, 2015 No problems to report with HKS Hipermax ! 1 Tilly reacted to this Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 13, 2015 Hmmm.....seems weird though as it was fine on standard suspension and it not as bad with the shock set to full soft. Will wait and see what BC come back with and my alignment guys say tomorrow. Share this post Link to post Share on other sites
Tweedbean 151 Report post Posted February 13, 2015 I had knocking at the rear after I had fitted BC's on my Mini. From what we understand it's the type of top mount they use which is prone to knocking. Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 15, 2015 After discussions with the supplier, we agreed to take the rears off the car just to eliminate anything else. However, what I have found is that once the rear is jacked up and the wheels removed I could actually put my hand on the spring and spin it on the perch. I could also grip it and rock it back and fore slightly and as it moved you could hear a small clunk. My guess is when it's going over a bump and the shock is extending the load is coming off the spring and allowing it to move slightly resutling in the knock. Either way, they're off the car for the moment and the standard stuff is back on the rears with no knocking. So we're going to run this by BC on Monday and see what they come back with. Hopefully they agree that'll be why and we need to add some pre load to the spring as they were fitted exactly as they came out of the box with no adjustment. If they believe it to be something else then obviously it'll go back. I'm just hoping if they do say to add pre load and I put them back on that it doesn't knock! Jamie, just to check did you ever have yours properly set up with the pre load adjusted? If its not too much trouble, could I ask you to try the same on your rears? Whether the spring with turn and rocking it back and fore produces a knock? Thanks Share this post Link to post Share on other sites
Lauren 2259 Report post Posted February 15, 2015 Surely though you can adjust the ride height at the bottom and the preload at the top? So can't you just pre-load the spring? Share this post Link to post Share on other sites
Tweedbean 151 Report post Posted February 15, 2015 Preload will resolve the spring moving. Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 15, 2015 Oh yes certainly they can be adjusted that way I was just merely seeing if anyone else has had the same issue from them as they were installed as they'd come out of the box. BC's initial reply was that it was a fault with the car, something to do with a problem across the rear deck where the spot welds break and cause the panels to knock together. I removed them purely as a process of elimination exercise and so we could feed that back to BC on Monday. Hopefully adding pre load will just solve it, but I'd like to see their response first as if we go by what they tell us to do, they can't say we did something wrong Share this post Link to post Share on other sites
Lauren 2259 Report post Posted February 16, 2015 It doesn't sound like they were preset when you got them from what you say! Seriously just get them setup properly when you have the geo done there's no other way to do it. Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 16, 2015 Yeah, I'm pretty sure it is just that. Would just be nice to have them clarify as like I say I know a few people have gone back with the same issue and been told it's the car. But hey ho, I'll dial some pre load in and refit. Fingers crossed Share this post Link to post Share on other sites
Qu1nt 1 Report post Posted February 20, 2015 I have BC coilovers & a very similar problem I've had them on the car for 6 months & the knocking noise from the rear started after approx 3 months They've been off (& back on) numerous times to try & find the problem (inc removed/refitted my adjustable rear arms) to check tightness & preload etc but with no success & nothing appears loose on the coilover or suspension (which is surprising considering how loud the noise is) I've just this week carried out the rear deck mod/adjustment but as suspected it made no difference so will be back onto them again next week ... Will follow this thread with interest & also let you know how I get on Chris Share this post Link to post Share on other sites
Jamie_GRMN 177 Report post Posted February 20, 2015 i think I have the perfect set of BC's judging by the threads on here... Thank you Toyokid Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 20, 2015 I am in direct contact with the BC UK distributor at the moment. They've advised me on recommended preload to add, and about tightening the top screw. So I'll give that a bash over the weekend and report back! Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 21, 2015 Just to keep you updated, Pre load added in as per their instructions and top nut also adjusted. Knocking had reduced but not totally eliminated, have fed this back and awaiting further instructions Share this post Link to post Share on other sites
Deacon 1357 Report post Posted February 21, 2015 I'm pretty sure there's quite a lot about this problem over on the frs forum. Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 21, 2015 Yeah. I have read up about it on the frs forum. Just seems weird where some owners don't get it, but majority of owners do. I'll see what they advise in the week and possibly consult with my setup specialist Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 25, 2015 So the advice received is to strip the unit down (remove spring and locking collars) and test the movement of the damper. I'll be hopefully doing that over the weekend. I suppose the plus point is the knock isn't getting any worse! Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted February 28, 2015 Test carried out, knocking from both still apparent. Have contacted them back to see where to go next. Have also been doing some research, spoken with a few others who've had the problem, one who's investigating now also. As well as spoken with another retailer who has had no issues with any kit they've supplied and fitted bar one recently which was returned and rectified. So we shall wait and see! 1 beexpwebsa reacted to this Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted March 3, 2015 Rears now removed again, standard suspension reinstalled. Distributor want the units back for further testing. Will keep you updated when I know more. Fear not knocking BC owners, we shall hopefully find a solution 1 Keethos reacted to this Share this post Link to post Share on other sites
STEVO9000 54 Report post Posted March 18, 2015 Looks like a light at the end of the tunnel! Although my units passed the dampner test when they went back, the UK distributor (Apex) have now advised that as the problem is becoming more and more highlighted across many people who run these on GT86's (I am aware of another 2 sets that went back in the same week as mine!) that a factory redesign of the units is being implemented as we speak and will be ready for testing with Apex in 2 weeks, following that providing all is successful they will then be issuing fixed units! 1 Keethos reacted to this Share this post Link to post Share on other sites
Special K 442 Report post Posted March 19, 2015 I get a knocking on the rear, i'm on teins though. It's nothing to do with the coilovers as far as i'm aware. Just a creaky panel somewhere Not a panel, have a tweak for this. Cost Pitman and I a test session at Millbrook with Colin, Mark, Adrian.... Cost you a grand for the answer... Spec K Share this post Link to post Share on other sites
rob275 1817 Report post Posted March 19, 2015 Not a panel, have a tweak for this. Cost Pitman and I a test session at Millbrook with Colin, Mark, Adrian.... Cost you a grand for the answer... Spec K You can have a pint! Share this post Link to post Share on other sites
