rich2342

iTrader: (3)

I am trying to get my car ready for summer with a fresh inspection etc..

I have had a suspension issue I noticed late last year before putting the car away for winter hibernation.

I have bc coilovers, hotchki's sways with SPL endlinks with no aftermarket front control arms. It was aligned as much as could be also.

Factors: I have changed a full set of tires at different times. I have 255 nexens n3000 in the front a better quality 275 rear tire set I had installed last season(name escapes me). I first had this set up with Dunlop starspecs all around in the above sizes and no issues with tail wiggle or tracking straight.

Now on the highway above 70 or so, slight inputs to the wheel cause a side to side unsteadiness which is pretty unsettling. If i test the car hard side to side around 35mph it sticks and bites, I don't feel the wiggle as much into the turn. It mostly is straight highway left and right sway or wiggle with minimal input.

I suspected Front lower control arms, but just had it looked at front and rear and they said no visible tearing?

What the hell can this be, i want to get it fixed but don't know where to start.

MicVelo

I would start with the obvious deviating factors: Tires and even more obvious, tire pressure. (I know, stating the TRULY OBVIOUS but y'never know, particularly if you had a pressure differential that you didn't think about when you put it away for the winter.)

Fact that you have two different brands of tires on the car MIGHT also be contributing to the unsettling at highway speeds. No matter what people say about running mixed sets, it's always better to be running same-construct tires F&R (except of course under specific conditions. e.g. race, autocross, where running staggered *construction* is the key to a hot lap.)

Once you have that squared away and if the problem is still there, get an alignment check (free at most places cuz they want your alignment biz). I know you said you had it aligned but it is still possible that toe could be an issue.

Note: Following is guesswork... best one can do without putting hands on it.

Finally, if the techs just looked at your LCAs (AKA "transverse link") and/or your UCA (AKA "upper link"); that is, just did a visual, it still could be a problem with any of these components or, more likely, a bad compression rod (and/or the CR bushings, which are known to go bad on Zs) which could cause such "inaccuracy" in the front suspension.

Any/all of which can be keeping your tires planted correctly - which is what is causing sway/wiggle at speed.

You'll need a good front end tech to understand where the problem may lay or if you can do it yourself, great!

Hope that helps some.

Mic

rich2342

iTrader: (3)

Thanks for the input.

I can get the oem front Lower control arms at a good price under 200 bucks and could probably throw those on there myself with a bit of labor. Was thinking of trying that, but due not really knowing the status of the bushings, don't know if it would be helping?

When I tested side to side wiggle it felt like one of those kids horses suspended by springs on each corner, where if I gave it a turn left and then right, it might follow the motion on its own, yet the tires felt planted.

rich2342

iTrader: (3)

Welp, Wasn't tire pressure.

I inflated all 4 to 35psi. I tried a hard acceleration and felt like the back end was floating. This is driving me nuts.

Spike100

The problem is running different tires front to rear. (As Mic mentioned previously)

rich2342

iTrader: (3)

I just find it hard to believe that tires while inflated at the same rate would cause floating and the uneasiness I am encountering.

When I had my stock wheels, those were mismatched front to rear and this wasn't an issue.

guitman32

iTrader: (15)

Let me confirm that swapping tires can make an enormous difference in the ride and feel of a car, all other things equal. Just today on my DD I just swapped sets of wheels and tires, and holy moly everything is different between the different tires.

That side to side motion while stationary is exactly the kind of thing that will differ hugely tire to tire, and also depend on the ratio of tire size to wheel width.

You never mentioned exactly what modification lead to the change in vehicle behavior . Did you notice the problem when you put the 275s on the rear, or when you added the front tires? Did the problem set in immediately after a change or did you notice a gradual degradation?

Absolutely the last thing you should do is throw bushings and control arms at the issue.

terrasmak

iTrader: (8)

What size tires are you running , width , aspect ratio and wheel size

labelworkshop75

iTrader: (13)

I would check your differential bushings.

Lug

Check:

Tire pressure
Alignment (Make sure your toe isn't to straight. If its to straight it can make it hard to steer straight)
Bearings
Bushings (You may have to remove the arms to really tell if they are torn)
Ball Joints (Make sure they move smoothly but with some resistance - is the boot torn)
Rack and Pinion (If it looks "wet" you might have a leak)
End Links (Do they squeak, or clunk over bumps at low to mid speed - are the nuts tight)
Shocks (Does you car nose dive forward when applying the brakes - does it lean to one side on level ground)

Spike100

The problem you describe happens when the tires (different bands/types front to rear) do not have identical sidewall stiffness. You can sometimes “apply a patch” by fiddling with the tires’ inflation. You simply overinflate the tire with less sidewall stiffness, or slightly under-inflate the more rigid tire.

rich2342

iTrader: (3)

255/35/18 f 275/35/18 r

rich2342

iTrader: (3)

I did have the diff bushing replaced as I experienced a torn OEM bushing 3 years ago. If I remember I have the Energy suspension Diff bushing installed.

Lug

Are your steering issues similar to the one in this thread?

guitman32

iTrader: (15)

Some clarifications:
Alignment - zero toe will cause the car to feel darty, but wont make it "hard to steer straight"
Bearings - I highly doubt blown bearings will cause these symptoms
Rack and Pinion (If it looks "wet" you might have a leak) - A leaky rack I do not think will cause this
End Links - likely not the cause either
Shocks - damper condition has nothing to do with ride height

terrasmak

iTrader: (8)

But a bad shock can easily make the car sway

guitman32

iTrader: (15)

Absolutely. Prime suspects for the OP are tires and shocks. And agree with Lug (despite the minor clarification) that if the OPs toe is off it may cause dartiness at speed which may also match the symptoms.

Wondering where the OPs BC coilovers damping is set.

rich2342

iTrader: (3)

The coils seem to be ok, but not sure how I would rule those out as a factor?

I have varied the settings from med to full stiff to see if that might be it. I mean, the wheels feel planted and there is no real pull from one side or the other, yet at highway speeds the uneasiness begins it feels as if something in the rear end could come undone.

It's hard to describe without experiencing it.

Spike100

Change the tires so that you are uniform front-to-back, and your problem goes away. --Spike

Lug

Alignment - Zero toe Read paragraph "What is Toe?" Third sentence. Also the link I posted for the Altima wandering issues were solved by adding some toe in.

Bearings - Follow the link bullet points 2 & 3. Just saying it "could" be a possible cause.

Rack and Pinion - A leaking rack pinion can lead to all kinds of steering issues - possibly the issues the op is having. If the rack and pinion is leaking it needs to be replaced.

End links - You are right, I should not have listed end links as a possible cause to his steering issues.

Shocks - Believe it or not, shocks and struts can cause a car to lean. If the shock is "pinched" or binding it can cause it to lean. Its rare, but it does happen.