Front Coil Hitting Sway Bar

[Paul-JK]

I've discovered a problem with my front drivers side coil on the JK and I was hoping that someone had seen this before and has a fix for it.

Quick bit of background......I've got a 2.5" lift using SS flexy coils, adjustable front track bar to re-centre the axle and adjustable LCA's to sort out the caster. When I was under the JK the other day I noticed some paint missing from the bottom 3 or 4 coils of the drivers side spring.



After a bit more investigating it seems that, with the sway bar disconnected (and tied off so it stays horizontal), the end of the sway bar is hitting the front of the coil as it flexes.



I've tried adjusting the LCA but I can't seem to stop it from happening. Adjusting the LCA to 585mm long (so about 9mm longer than stock) seems to minimise the contact but it still hits. If I have the LCA longer than that it pushes the coil seat (and therefore the coil) further forward making the contact worse, and if I have the LCA shorter than that in pulls the coil seat backwards (and downwards I suppose) but this causes the coil itself to bow forward as it compresses so it pushes into the sway bar.

The spring also bows sideways slightly as it compresses and is contacting with the bolt heads from the steering box bolts.



Has anyone had this happen before or does anyone have any suggestions as to how to stop it from happening? I've contacted Suspension Stuff but he says he's never seen it before. His only suggestion as to try the AEV drop brackets rather than the adjustable LCA's as that will reposition the diff better. I'm happy to try this but I thought I'd check and see what others thought first. Clearly another option is to increase my bump stops to prevent the coil from compressing so much. I already have about 20mm bump stop extension in which is enough to stop the shocks from over compressing but I think I'd need at least another 50mm on top of that to stop the coil from compressing so that it hits the sway bar.

The other thing to know is that this is only an issue on the drivers side. The passenger side coil does not bow side ways towards the chassis and still has a good 10mm of clearance to the sway bar under flex



If it was happening on both sides then I'd accept that I needed bump stops or a different diff angle but I've no idea why the passenger and drivers side seem to be behaving so differently. Any insight or advice would be greatly appreciated.

Thanks,

Paul

[SteveC]

Paul
As yrs is similar. Why not compare with mine and we can easier notice what may be wrong. I think there may be an issue with coils as i have nticed somthing odd as well
Steve

[Paul-JK]

Thanks Steve. Sounds like a good idea. Do you have 2 car ramps at your place so that we can get it flexed up? If not then I can bring mine over.

[SteveC]

Paul - Call me - but you'll need to bring the ramps
Steve

[Paul-JK]

Just as a follow up to this in case anyone has the same problem, after comparing my JK to others I couldn't see any logical reason why this should be happening other than using the adjustable LCA's to correct the caster after the lift. It was the only thing that I had different in comparison to others I looked at. So I decided to change over to using the AEV geometry correction brackets to correct the caster instead and see what they did.

Fitted them up this weekend. The install wasn't too bad other than having to cut the drivers side upper control arm chassis mount bolt off as I couldn't get it past the exhaust. Ended up blunting my saw blade so had to cycle to Autobarn to get a new blade as I couldn't very well drive there without the upper control arms connected. Then (and I still can't believe I managed to this) when putting the replacement bolt back in from the other side, which involves passing it through holes cut in the chassis rails I, yes you guessed it, I managed to drop a bolt inside the damn chassis rail . Pleased I had a spare! No doubt I'll regret that at some point when it starts to rattle but I couldn't feel it though any of the other holes in the chassis so I'll just keep poking my fingers inside the chassis at different times and see if it works it's way towards one of the holes at some point.

Anyway, the drop brackets seem to have fixed my problem. Haven't had it fully articulated yet but flexing it as much as I could on my ramps showed a good 10mm or so of space between the end of the sway bar and the coil. As an added bonus it's also given me a smoother, quieter ride with less harsh bangs coming through the front end when I drive over broken roads. Whether that's due to the angle of the control arms with the AEV brackets fitted or whether it's due to going back to the factory LCA's with rubber bushes both ends I'm not sure, but I suspect it'll be a combination of the two.

So, in a nut shell, with a 2.5" lift I'd definitely recommend using the AEV brackets for caster correction rather than just using adjustable LCA's. Perhaps if I'd used adjustable uppers instead, or both, I wouldn't have had this problem but for $100 + freight the brackets are a whole load cheaper and give a better ride to boot. OK, for some they may not be suitable if you're wanting to go more hardcore 4WD'ing and are concerned about losing the clearance but I think for the mix of driving that most people do (or most of the people that I know anyway) it's probably a worthwhile trade off. Now just got to get a trip planned off road, see what the ride's like on the dirt and get it flexed up properly and check out the clearances again.

[mikeb]

Yeah I've got the same issue with my passenger side coil. I'm just going to make a sway bar relocation bracket. Move it towards the front of the car by about 1". I've got synergy adjustable lower control arms. If you're interested I'll make two sets.

[rainman]

i have the same prob on my xj.
however with greased bushes the whole bar will rotate away from the spring once disconnected.
assuming you have a old school bar and not a electric new fangled set up.
my jk knowledge is limited at best.

[Paul-JK]

Yeah I've got the same issue with my passenger side coil. I'm just going to make a sway bar relocation bracket. Move it towards the front of the car by about 1". I've got synergy adjustable lower control arms. If you're interested I'll make two sets.

Strange that you have the issue on the passenger side as on the couple of JK's I've looked at all have had more clearance on the passenger side than the drivers side (the sway bar actually seems to be angled slightly from the factory with the fixing location to the chassis being fractionally further back on the drivers side).

I did think about making relocation brackets for the sway bar as well as this would very probably have fixed the issue but in the end just decided to try the AEV brackets as everyone who has them raved about them and said they improved the ride as well. So far I'd say they seem to be correct so I think I'll stick with the AEV brackets.

I now have a spare set of Synergy LCA's in the garage with my growing collection of bits from the JK that have been swapped out.

[SteveC]

Paul Now that you used the drop brackets - is your caster correct? Have you thought that rather the sway bar is slightly forward on one side - that it may be the axle slightly forward??

I think my left axle position is ever so slightly backward, may be 2-5mm. Rides smooth and OK but is tends to swerve left if you let go of the steering wheel only slight though. It follows the camber of the road but only a little. Even after re-alignment etc etc , If you hold the steering wheel it goes dead straight. Only if you let go. I have given up on trying to fix this. At one time I thought of using a RTC damper but they don;t make one for the JK.
Sorry a little off topic....

[Paul-JK]

Hi Steve,

To be honest I've not had my caster checked since I put the AEV brackets on, partly due to lack of time and partly due to the fact that all of the measurements I took seemed to indicate that the height of the lift put it where AEV said it should be to fit their brackets so I assumed it would (should) be OK. I do intend to get it checked at some point though, more out of curiosity than anything else. I need to get my wheels balanced so I'll get them to check the alignment at the same time.

Not sure about whether the axle is straight (or rather whether it's perpendicular to the chassis rails) or not. I know the measurements I took on both mine and George's JK showed the sway bar fixing location on the drivers side to be slightly further away from the front of the car than the passenger side though and by the same amount on both JK's.

My JK also pulls left just as you've described, and follows the camber of the road more that it did stock. I've spoken to a few people about this and they say it's normal after lifting a JK (and the slightly wider tyres will also follow the camber more as well). Shouldn't be too severe but it will happen and is damn near impossible to get rid of totally. I've also been warned off using an RTC dampened on the JK's but for the life of me I can't remember why now. I'm about to fit a aftermarket bilstein dampened to mine (along with the relocation bracket to move it out of the way) so I'll see if that has any effect as hopefully it'll be a better dampened that the stock unit.