Control Arm Bushings

[D.J.]

Ok, it seems my Stinger is attracting some bad omens.

Today I went to the dealer to have the last set of front bushings replaced. After the curbed control arm bushings and the stabiliser bar bushings, today they replaced the forward arm bushings (the straight arm). I wanted them replaced simply because they were squeaking over bumps.

After they finished I got in my car and instantly realized something was way off.
The steering was VERY soft turning right and VERY heavy when turning left. It was like the steering had its own plan of where the car should go. Really impossible to drive.

Went back. They mentioned they had to disconnect the tie rods to get to the arm but that everything should be fine. They did a full reset of the computers but nothing. They did a full alignment but nothing changed. They checked the suspension again and all looked fine.

I left the car there over night to see what they can do tomorrow.
The behaviour is so strange! You start turning the steering wheel and it's very heavy or very soft for 2 seconds, then it suddenly changes weight or suddenly pulls or pushes in a direction. I was literally fighting the car to go in the desired direction.

The lane assist was fully off at all times. In any case, it was behaving the same at all speeds, both in the parking lot and on the road.

Any ideas?
Did they break my steering? How!?

Does this heavy steering effort in one direction occur when parked as well? Or only at speed?

 

[Volfy]

Ok, but to happen while they are working on the car?! What could trigger it?

That part of it was definitely something done wrong by the shop that worked on your car. Sounds like they didn't center the steering correctly. For the electric power steering assist to work, it must know accurately where the center of the steering wheel is, so it can meter the correct amount of assist one way or the other, depending on how far away from center the steering wheel the steering angle is at any time.

If they did not physically set the steering at center before the loosen the tie rod arms - and keep it exactly centered as they replace the tie rod arms, they could put your car in a situation where the front wheels are pointed straight ahead, but internal steering angle in the control unit is not at dead center.

That said, dealer service depts have access to factory software tools that can reset the internal steering angle to zero. Us shadetrees don't. That's why when I work on tie rod ends, I have to watch out for the above issue. I've gotten it messed up on another car before, causing the body controller to get all confused, including stability control. An independent shop may or may not have access to the software tool. So when you say the shop did a "reset", I dunno if that means what I think it means.

 

[7Andrei7]

Does this heavy steering effort in one direction occur when parked as well? Or only at speed?

Yes, it has the same behavior while in park. It keeps changing the level of steering assist depending on which way I turn the wheel. Heavy in one direction and very light in the other direction. But this also keeps randomly changing. It wasn’t always left = heavy and right = light. It kept switching.

 

[7Andrei7]

@Volfy this was done at the Kia dealership. The one that maintained my car since day one.
Very strange.
I’m still hoping it could be something they did wrong and can be undone.
Otherwise, it looks like I’m without a car for a while.

 

[Volfy]

Maybe they put the new guy on this job... I'm at a loss. Cannot imagine the dealer service bungle a relatively simple job like this, but who knows.

Still sounds like they didn't zero the steering angle correct, so whenever the body controller thinks the steering angle cross zero (center), it switches the electric power assist the other way.

 

[D.J.]

Yes, it has the same behavior while in park. It keeps changing the level of steering assist depending on which way I turn the wheel. Heavy in one direction and very light in the other direction. But this also keeps randomly changing. It wasn’t always left = heavy and right = light. It kept switching.

Never heard of that. Something is off
Did the dealership not perform a test drive after the alignment?

Is it an intermittent issue? How did they not detect it immediately?

 

[7Andrei7]

Never heard of that. Something is off
Did the dealership not perform a test drive after the alignment?

Is it an intermittent issue? How did they not detect it immediately?

They did not even plan to do an alignment. Told me it’s not necessary. So probably no test drive either.

When I got in the car and immediately spotted the problem, I went back to the front desk to let them know and they said they will make a full reset + alignment. By the time they finished all mechanics had left.

I did a test drive but nothing had improved and everyone was already gone. I got the front desk guy to try the steering and he understood the problem. Said he can’t let me leave with it like that so had to leave it there overnight.
They gave me a replacement car. A 100hp kia ceed

 

[7Andrei7]

Today they took everything apart and put it back together. Nothing changed.
They did a calibration of the steering. Nothing.

Now they are hinting at the bushings being to blame and suggesting that it's my fault for only changing the bushings instead of the whole control arm. I challenged them on how a bushing can cause the steering to behave erratically while the car is standing in Park. They couldn't explain.

The car is still with them. I'm with the 100hp kia ceed. I can't believe this is happening.

 

[Ohiocruiser]

That sucks. Looks like kia dealership experience is a worldwide phenomena.

 

[Volfy]

Yeah the bushing couldn't possibly have caused that behavior. I hope they fixed it up soon. This has been quite a saga for you.

I suppose I should count myself lucky, in that I have not had a car that needed anything more than maintenance or regular wear and tear items, much less stuff that can be considered major repair. Knock on wood.

 

[D.J.]

They did a calibration of the steering. Nothing.

This is very surprising
I expected that to be the solution.

Good luck with the diagnosis. Kia dealerships are not know for their world renowned diagnosticians.

 

[7Andrei7]

Ok, the verdict is in: they need to replace the whole steering "Gear & Linkage Assembly".
They still did not explain how they messed it up but also didn't pretend like it was broken before. They will fully cover the cost for this (4500 EUR).

However, they keep insisting I should replace the whole control arm. Although I now have the new bushings in place they claim that it's strongly unrecommended to change only the bushing on those control arms.

They basically said that in order to be able to guarantee that the car will be fine I should replace them. The cost of both control arms will be around 700-800 EUR.

Can anyone understand a potential problem to leaving the old control arms with the new bushings in place? Thanks!

 

[7Andrei7]

Car is back with a new steering gear, motor & linkage assembly. They kept the old control arms with the new bushings.

No more erratic steering. No more squeaks over speed bumps.
The whole front end feels much more solid than before. I basically now have new bushings on both arms and on the stabilising bar plus new steering links. Feels like a new car at 190k km. Happy owner!

 

[DeltaV]

Front Radius Arm To Chassis Mount Bush Kit - Caster Adjustable Kia Stinger

Control arm bushings form the vital pivot and link between all core suspension components. SuperPro's 'offset' bushing options introduce additional positive caster into the front end suspension geometry. With a small but significant change the additional caster delivers several benefits...

superprousa.com

Only bushing I can find for the Stinger. I wish they made ones for the camber arm too.

Apologies for bringing this thread back from the dead and to change the subject a bit, but has anyone found a source for the large bushing on the straight (camber) arm?

Specifically, I’m looking for a source of slightly offset bushings to induce additional camber by pushing the bottom of the kingpin away from the car’s centerline.

I figure this would be easier than ovaling the bolt hole, tack welding two “ears” on the subframe carrier, and replacing the bolt with an eccentric alignment bolt, though I wouldn’t gain adjustability.

Thoughts?

 

[Volfy]

Apologies for bringing this thread back from the dead and to change the subject a bit, but has anyone found a source for the large bushing on the straight (camber) arm?

Specifically, I’m looking for a source of slightly offset bushings to induce additional camber by pushing the bottom of the kingpin away from the car’s centerline.

I figure this would be easier than ovaling the bolt hole, tack welding two “ears” on the subframe carrier, and replacing the bolt with an eccentric alignment bolt, though I wouldn’t gain adjustability.

Thoughts?

That isn't a camber arm. Changing the length of it would change not only camber but also toe, and it might even vary caster a little. You should be able to readjust toe angle using the steering pushrods, so I support that could be useful for adjusting static camber angle.

More importantly though... because the front suspension is of MacPherson strut type, changing that lower control arm length would also alter the dynamic camber gain/loss... most likely not in a good way. For that reason, I doubt you'll find anybody selling a replacement adjustable bushing.

 

[DeltaV]

That isn't a camber arm. Changing the length of it would change not only camber but also toe, and it might even vary caster a little. You should be able to readjust toe angle using the steering pushrods, so I support that could be useful for adjusting static camber angle.

More importantly though... because the front suspension is of MacPherson strut type, changing that lower control arm length would also alter the dynamic camber gain/loss... most likely not in a good way. For that reason, I doubt you'll find anybody selling a replacement adjustable bushing.

Agreed, it isn’t a camber arm. I was reusing the previous poster’s term to avoid adding nomenclature.

Yes, “extending” that arm would further open toe, (I’m running 0.10° out, anyway) and correcting that would realize less caster. Spec is 6.4 to 7.4. I’m running 6.9 but would prefer a bit less.

Toe and caster are adjustable. Camber is not, and it is uneven, left-to-right. I haven’t determined how much offset I would want but I know how to determine that and that it would differ, left-to-right in my case. I’m expecting a fixed solution, but adjustable.

Before I go to the trouble (simultaneously inspecting dynamic camber changes while on the rack), I’d like to have a supplier so I know exactly what information they would need and in what format.

Sincere thanks for looking out for my best interests. Mistakes here can be dangerous. I don’t KNOW that this is a solution, but I know that I’m driving on the outer shoulder of the tire and very experienced with much better suspension designs. I’m trying to learn and adapt MacPherson to be useful.

Hoping for a source that’s willing to discus custom solutions.

 

[Volfy]

Agreed, it isn’t a camber arm. I was reusing the previous poster’s term to avoid adding nomenclature.

Yes, “extending” that arm would further open toe, (I’m running 0.10° out, anyway) and correcting that would realize less caster. Spec is 6.4 to 7.4. I’m running 6.9 but would prefer a bit less.

Toe and caster are adjustable. Camber is not, and it is uneven, left-to-right. I haven’t determined how much offset I would want but I know how to determine that and that it would differ, left-to-right in my case. I’m expecting a fixed solution, but adjustable.

Before I go to the trouble (simultaneously inspecting dynamic camber changes while on the rack), I’d like to have a supplier so I know exactly what information they would need and in what format.

Sincere thanks for looking out for my best interests. Mistakes here can be dangerous. I don’t KNOW that this is a solution, but I know that I’m driving on the outer shoulder of the tire and very experienced with much better suspension designs. I’m trying to learn and adapt MacPherson to be useful.

Hoping for a source that’s willing to discus custom solutions.

If you just need to correct camber, you'd be better off going with coilovers that have top camber plates. That is one of the main reasons we are running Riaction coilovers. Sliding strut top anchor point does not change either toe or caster appreciably, so that is about as close to a pure camber adjustment as it gets. That said, that camber change does also shift the scrub radius slightly, but it doesn't mess with the entire front suspension geometry, to the degree that varying that lower arm length would. So it's a much better way to adjust camber on a strut front suspension with cup & cylinder lower mount, like the Stinger.

BTW, stock front suspension is not caster adjustable. To do that, you'd need to get that SuperPro bushing kit - or the very similar Whiteline version (which is what I bought).

 

[DeltaV]

If you just need to correct camber, you'd be better off going with coilovers that have top camber plates. That is one of the main reasons we are running Riaction coilovers. Sliding strut top anchor point does not change either toe or caster appreciably, so that is about as close to a pure camber adjustment as it gets. That said, that camber change does also shift the scrub radius slightly, but it doesn't mess with the entire front suspension geometry, to the degree that varying that lower arm length would. So it's a much better way to adjust camber on a strut front suspension with cup & cylinder lower mount, like the Stinger.

BTW, stock front suspension is not caster adjustable. To do that, you'd need to get that SuperPro bushing kit - or the very similar Whiteline version (which is what I bought).

Excellent information, thanks.

My use case benefits from the electronically controlled suspension and Mando tuning module that precludes full replacement. (Aren’t all Stinger front ends coilovers? I know the rears are not.)

Now, if Megan (or others) sold the camber plates separately and could accommodate the tops of the stock electronic units I’d have the solution I was looking for two years ago, but I gave up on that, finally, and started looking at the bottom end…a much less preferable option, but one I had not yet abandoned.

I had hoped that the BMW camber late solution to Biermann’s decades-long error would translate to the Stinger, but only, it appears, as a complete strut replacement…with such a small performance sub-culture, that does make business sense, but leaves me dangling.

 

[Volfy]

Aren’t all Stinger front ends coilovers?

They are MacPherson struts. Coilovers commonly refers to an assemblies of replacement coil-spring over shock body that are adjustable for ride height and spring preload compression. Many (though not all) also incorporate adjustable to camber plate. Stinger OEM struts have no such adjustabilities.

AFAIK, no aftermarketeers make a camber plate that directly bolt on to Stinger OEM strut, replacing the OEM strut top bearing. Likelihood of something like that is next to nil. The OEM front spring diameter is too large to allow for the center top anchor point to shift far enough to affect camber angle appreciably. Besides, the top of the spring is usually very tight up against the strut tower, which makes shifting anchor point difficult, if not impossible.

Aftermarket coilovers typically utilize much narrower (standardized) diameter springs, which are available from automotive spring mfrs in different free lengths and spring rates, which facilitate a wide latitude of suspension tuning. That makes a quality aftermarket coilover kit much more appealing option for drivers looking for setups that are optimized for their individual application and usage case.

 

[DeltaV]

They are MacPherson struts. Coilovers commonly refers to an assemblies of replacement coil-spring over shock body that are adjustable for ride height and spring preload compression. Many (though not all) also incorporate adjustable to camber plate. Stinger OEM struts have no such adjustabilities.

AFAIK, no aftermarketeers make a camber plate that directly bolt on to Stinger OEM strut, replacing the OEM strut top bearing. Likelihood of something like that is next to nil. The OEM front spring diameter is too large to allow for the center top anchor point to shift far enough to affect camber angle appreciably. Besides, the top of the spring is usually very tight up against the strut tower, which makes shifting anchor point difficult, if not impossible.

Aftermarket coilovers typically utilize much narrower (standardized) diameter springs, which are available from automotive spring mfrs in different free lengths and spring rates, which facilitate a wide latitude of suspension tuning. That makes a quality aftermarket coilover kit much more appealing option for drivers looking for setups that are optimized for their individual application and usage case.

Yeah, I’ll admit that was a joke since “coil over” has for the 4 decades I’ve been tuning suspensions referred only to the coaxial layout of the spring and damper.

Somewhere along the line the term got bastardized to refer to height-adjustable perches, adjustable dampers (whether single or double), smaller diameter coils, etc.

The MacPherson strut is actually a coilover, just a design to make front-wheel-drive cars easier and cheaper to manufacture at the expense of native handling and adjustability.

I’m struggling trying to make my first non-SLA design handle reasonably (since I had to give up my rotaries to satisfy new family demands) knowing this solution was good for the rest of my needs, just trying to scratch back some basic handling performance without permanently altering other vehicle dynamics.

How is camber adjustment not a basic human right??? Who cares about ambient lighting color and how did that take priority over basic suspension minimum standards…for a car Kia was using to expand into the sports sedan market?

Yes, a full suspension swap would be the easy solution and one I’ve done dozens of times for previous builds (from bolt-on street prep to a custom-built setup whose twin won the USRRC GT2 championship in the late ‘90s), but this time I need as much Dr. Jekyll as I’d want Mr. Hyde.

I keep promising myself to give up and just drive it like the Camry it seems to have been designed to emulate but the draw of building a 4-door FD just won’t go away.

My own fault, of course.