Crappy handling

[ImaginationLand]

Okay, so since I bought this Cobra, I've had problems with steering wheel play and all around crappy steering/handling. I have done the following mods to try and correct this:

MMFLSFC's
MM Bumpsteer Kit front and rear
New Bilstein Struts/Shocks
H&R Race Springs
New OEM control arms with Steeda X2 balljoints
MM Solid Steering Shaft
MM Solid Rack Bushings
Remanufactured Cardone SPR-ZM Steering Rack
New OEM hubs
New Rotors/Hawk Pads
Tires balanced
New wheels and tires


The steering wheel shakes badly over 55MPH and it isn't just tramlining. I can feel that, but the steering wheel/tires move left and right over bumps, so I assumed it was bumpsteer but that was installed by a shop and they said there is no bumpsteer. They did not give me any measurements or anything though. I've had to get an alignment about every 6 months for the past two years. Seems like it consistently goes out of alignment and handles like crap after a while. I get an alignment and that helps for a while, but then it returns to crap. I do have some SFC Caster/Camber plates which may be causing the problem. I have some MM c/c plates that I'm going to install soon as well. I just feel like I keep throwing money at it and it doesn't get any better. Any ideas? Sell it?

Also, grabbing the wheel at 12 o'clock and 6 o'clock positions show no play after the new hubs were installed. Before that, there was a little bit of movement. At the 3 and 9 position the wheels move back and forth but so does the steering wheel. Even when locked. Not sure if I'm testing that correctly. :??:

Thanks for the help
:beer:

 

[03 DSG Snake]

Install the MM plates then take it to a shop for alignment that knows what they are doing.

To really bumpsteer a car the springs need to be removed. I doubt yours was setup properly. I have very similar mods and have no issues with going out of alignment.

 

[forcefedcobra]

sounds like your inner tie rods need replaced. its a common problem. I've replaced mine once every year or so.

 

[ImaginationLand]

I thought that too, but the replacement rack came with new inner tie rods. Always worth a shot. Do I have to remove the rack to change the inner tie rods?

 

[forcefedcobra]

I thought that too, but the replacement rack came with new inner tie rods. Always worth a shot. Do I have to remove the rack to change the inner tie rods?

went back and read everything again. You said with the stearing wheel locked and pushing on the wheel in the 3/9 position the stearing wheel still moves?

 

[ImaginationLand]

From what I can tell, yes.

Jack up car
Steering wheel in locked position.
grab at 3 and 9 and move the wheels left and right and both wheels move together and the steering wheel moves a little bit. Maybe .5" to 1".

I'm not pushing in and out, but grabbing the left side of the tire and right side of the tire and pulling on left side of tire and pushing on right side. Both tires move about half an inch and the steering wheel does the same. I don't think I'm testing that correctly.:??:

 

[forcefedcobra]

From what I can tell, yes.

Jack up car
Steering wheel in locked position.
grab at 3 and 9 and move the wheels left and right and both wheels move together and the steering wheel moves a little bit. Maybe .5" to 1".

I'm not pushing in and out, but grabbing the left side of the tire and right side of the tire and pulling on left side of tire and pushing on right side. Both tires move about half an inch and the steering wheel does the same. I don't think I'm testing that correctly.:??:

that's correct. push in on one side as you pull on the other and vice versa

 

[ImaginationLand]

Thanks for the help guys. I'll get a shop to correctly set bumpsteer and install the mm c/c plates and see how it performs.

Another thing I notice is if I gradually move the steering wheel left and right, turn to turn, there is a vibration/pulsation in the steering wheel. This is while sitting still. Just shakes left and right similar to what happens at 55+. It is a slight pulsation, not violently shaking back and forth. The shake is also intermittent on the highway. Sometimes it happens on the same roads, other times it doesn't, or at least I don't notice it.

Could it possibly be the power steering pump?

 

[black 10th vert]

It is most likely the steering shaft that is giving you the play. I installed a FR one to improve the handling, and steering feel on my car. What I found, though, is that the shaft did give more direct feedback and "feel" through the steering wheel, it also added play because of the tolerance between the input shaft of the rack, and the broached coupling that fits over it. This is because the factory one is a split coupling, so when you tighten the bolt, it clamps to the shaft and eliminates any tolerance. The aftermarket shaft has a broached coupling which has a few thousandths of tolerance to be able to slip onto the input shaft, but then relies on the crossbolt only to keep it from pulling off, but not for compression. Even though it is only a few thousandths at that interface, the tolerance really magnifies with the diameter of the steering wheel, where it translated into about 1/4"-1/2" of radial play. For a race car this is fine, but was totally unacceptable for a street car inmo, and cheapened the overall feel of the car to me. I ended up selling that, and putting the stocker back in, and have been happy ever since. I did use the MM solid mounting bushings, and that made a huge difference in steering feel, without the downside of the solid shaft.

No, it is not the pump, since that has no effect mechanically on the system - especially since you can feel the play with the car not running (I am assuming).

 

[RDJ]

check the balance of your drive shaft as well. what you can do is get under the rear of the car and turn the drive shaft by hand. there are weights attached to it and if one of them has fallen off you will get the kind of vibe you are talking about. the vibration will get worse the faster you go and will be felt most in the gear shift. when mine went out of balance I couldn't hold the gear shift lever to get it into 4th gear

Thanks for the help guys. I'll get a shop to correctly set bumpsteer and install the mm c/c plates and see how it performs.

Another thing I notice is if I gradually move the steering wheel left and right, turn to turn, there is a vibration/pulsation in the steering wheel. This is while sitting still. Just shakes left and right similar to what happens at 55+. It is a slight pulsation, not violently shaking back and forth. The shake is also intermittent on the highway. Sometimes it happens on the same roads, other times it doesn't, or at least I don't notice it.

Could it possibly be the power steering pump?

 

[ImaginationLand]

check the balance of your drive shaft as well. what you can do is get under the rear of the car and turn the drive shaft by hand. there are weights attached to it and if one of them has fallen off you will get the kind of vibe you are talking about. the vibration will get worse the faster you go and will be felt most in the gear shift. when mine went out of balance I couldn't hold the gear shift lever to get it into 4th gear

I don't feel it in the gear shift. Steering wheel only. It clears up around 75-80mph and below 50mph. Tires have been balanced twice with no change. I did seem to notice this the most, soon after changing the front rotors.

It is most likely the steering shaft that is giving you the play. I installed a FR one to improve the handling, and steering feel on my car. What I found, though, is that the shaft did give more direct feedback and "feel" through the steering wheel, it also added play because of the tolerance between the input shaft of the rack, and the broached coupling that fits over it. This is because the factory one is a split coupling, so when you tighten the bolt, it clamps to the shaft and eliminates any tolerance. The aftermarket shaft has a broached coupling which has a few thousandths of tolerance to be able to slip onto the input shaft, but then relies on the crossbolt only to keep it from pulling off, but not for compression. Even though it is only a few thousandths at that interface, the tolerance really magnifies with the diameter of the steering wheel, where it translated into about 1/4"-1/2" of radial play. For a race car this is fine, but was totally unacceptable for a street car inmo, and cheapened the overall feel of the car to me. I ended up selling that, and putting the stocker back in, and have been happy ever since. I did use the MM solid mounting bushings, and that made a huge difference in steering feel, without the downside of the solid shaft.

No, it is not the pump, since that has no effect mechanically on the system - especially since you can feel the play with the car not running (I am assuming).

The issue was present before and after the solid steering shaft. Play in the wheel isn't my main concern, that was mostly resolved by the solid steering shaft. What bothers me is the shake in the steering wheel 55-75mph. The alignment is definitely off right now and is pulling to the right. But even after getting alignments, I still have the shake. It feels like something is broken up front. Inner tie rods sound possible, but they were replaced when I installed the new rack.

Could warped rotors cause this problem? I don't notice any additional shaking when I apply the brakes, unless it is in the same 55-75mph range. The shaking in the steering wheel is visible. If you were sitting in the passenger side you could see the wheel shaking back and forth. Over 75mph and it lessens a bunch. Then other times, at the same speed range, there is little to no shaking. Happens every day, but even on the same roads, sometimes it shakes, sometimes it doesn't. Pretty random.

Since it doesn't happen ONLY when I'm braking, I didn't figure the rotors would cause it, but that is when I first noticed it. Then I started replacing all the other parts trying to remedy the issue.

And the pulsation in the steering happens when the car is running, sitting in neutral, moving the steering wheel all the way to the left and all the way to the right. Like a pulsation, or feedback from something. Only if I slowly turn it lock to lock.

Forgot to add that I replaced the swaybar bushings and end links as well.

 

[racebronco2]

It's the rotors. If they are really bad then you will feel it when you brake also. I have the same pulsation at idle if i go lock to lock. I just give it a little more gas and it seems to help. I think the pump pressure is too low at idle.

 

[black 10th vert]

I agree with the possibility of the rotors, so if you can find someone with a spare, known good set, it may be worth a quick swap to see if it helps, then you can just invest in some new ones (or buy the used, good ones). The other possibility is the front tires. You could have a factory defect in the tires, where a belt is messed up, and no amount of balancing will correct that. I get a slight vibe from flatspotting after my car sits for a long time, but it resolves after a few runs, and is similar to what you describe at speed.

 

[racebronco2]

You can check them with a dial indicator.

 

[ImaginationLand]

I agree with the possibility of the rotors, so if you can find someone with a spare, known good set, it may be worth a quick swap to see if it helps, then you can just invest in some new ones (or buy the used, good ones). The other possibility is the front tires. You could have a factory defect in the tires, where a belt is messed up, and no amount of balancing will correct that. I get a slight vibe from flatspotting after my car sits for a long time, but it resolves after a few runs, and is similar to what you describe at speed.

You can check them with a dial indicator.

I'm going to pick up some new rotors today and get them installed tomorrow. Then, MM c/c plates and an alignment. I will report back with the results. Thanks for all the suggestions.
:beer: