[fazeaway]

Ok, a while back I hit a nasty bump, everything seemed to be fine afterward when I had the car checked out.

A while after it happened I started having an issue. When cornering hard enough to the left the steering wheel would stutter and the car would try to pull to the right as I was turning. Almost like understeer with an added vibration. It actually sounded like I was running over a rumble strip whenever it would happen.

I just replaced the tires all around. I was driving it and went into a right hand turn. I experienced the same issue I did with the other side only this time the sound was much louder. This time around the car also slowed down by 20+ MPH.

It's almost as if the tires are rubbing something when I corner hard enough to cause the car to lean enough. I've looked at the tires the tread doesn't appear to have any signs of rubbing damage. I've also turned the wheels to their extremities and there seems to be plenty of clearance everywhere.

Tire sizes are the stock 225/45/18 fronts and 245/45/18 rears so clearance shouldn't be an issue.

Any ideas?

 

[thatguy]

Something's bent or a ball joint is shot

Did both front tires hit the "nasty bump"???
If not you might be able to compare pieces from the non-bump side to the bump side to check for irregularities...something that looks slightly different from one side to the other

 

[Gilley]

You might have a blown bushing in one of the lower control arms.

 

[poormansporsche]

Are you sure you're not getting ANY rubbing from the tire...particularly the inside edge? Have you taken off each wheel and seen if there is ANY "polishing" visible on the body/suspension behind the tire? Remember, just because the tire doesn't appear to contact at full turn lock (left and right) when you are stationary, doesn't mean that it won't when the tire is flexing and rolling to the side while under cornering forces.

 

[fazeaway]

Are you sure you're not getting ANY rubbing from the tire...particularly the inside edge? Have you taken off each wheel and seen if there is ANY "polishing" visible on the body/suspension behind the tire? Remember, just because the tire doesn't appear to contact at full turn lock (left and right) when you are stationary, doesn't mean that it won't when the tire is flexing and rolling to the side while under cornering forces.

Rubbing was my first assumption given the sound produced. I can't see any "polishing" but I've not had the chance to take the wheels off to get a closer look. If there is any polishing what do I need to look at replacing?

 

[poormansporsche]

Rubbing was my first assumption given the sound produced. I can't see any "polishing" but I've not had the chance to take the wheels off to get a closer look. If there is any polishing what do I need to look at replacing?

Pretty much what others have already been saying... bent tie-rod, ball joint, shattered control arm bushing....etc

 

[Randy]

Slowing down with vibration is usually bad wheel bearing ... It will keep getting worse, and finally start pulling even in a straight line.

It doesn't have anything to do with your tires.

 

[thatguy]

wheel bearings! good thinking, definitely something to check

quick way to tell...jack a front wheel off the ground and try to push and pull the top of the wheel in and out of the fender well, basically cross-wise from the direction of rotation. Do not use the front of the wheel to try this as it would be similar to steering the wheel and could seem loose but the steering is just moving. Any play is probably not good and could be from bad bearings.

 

[poormansporsche]

Slowing down with vibration is usually bad wheel bearing ....

....or brakes!

 

[fazeaway]

I took the wheels off. No signs of rubbing or polishing anywhere on the car or the wheel itself. I also checked for any play, nothing there either.

If brakes were the issue wouldn't I have shaking or something under braking?

Also when lower control arms are bad, doesn't the car have a tendency to pull to one direction or the other under heavy acceleration? I could be wrong but that's what I've been told. If so, this is not happening either.

As for wheel bearings, there is no noise when driving under normal driving conditions while turning or otherwise at any speed.

It just seems like anything that could explain the problems isn't exhibiting any of the symptoms that usually come with that problem.

I could be wrong about all of these but I'm just basing my assumptions off of what I've been told by other people and mechanics. Feel free to set me straight on any of this. Just trying to troubleshoot the problem without taking the "replace every part until it goes away" approach, lol.

 

[[email protected]]

Are you braking in these corners? if so it could be your brake rotors. I had this problem with my last car. they got a little warped from heat and when you turn the left with brakes on, serious virbration appreared in the steering wheel. I replaced the rotors and it went away.

I would take both the tires off and look through it carefully. If its not the rotors, I would suspect a control arm is f'd.

 

[fazeaway]

Ok, so after checking the front end everything is absolutely fine up there.

After that I decided to find a nice curvy road to try and duplicate the problem. Low and behold there it was. This time I noticed the "slip" light flickering when it happens. Tried the same test with VDC off and it didn't do it once. Looks like the problem is actually in the rear end. The stuttering from the VDC was just enough to cause a shimmy and slow the car down.

The best I can figure is that the clutch(es) in the rear end are slipping.

I changed the fluid in the rear end and added some posi-trac additive. The fluid that was drained out looked perfectly fine, no grit or anything. Going to let the new fluid and additive work into the rear end. Hoping that will fix it. If not, any suggestions?

 

[Gilley]

My suggestion is not to add the traction additive. Use the grade of fluid in the rear differential as required by Nissan.

since you didn't feel the problem with VDC off, maybe the shudder you feel is the VDC at work. you might be overdriving the traction limits of the tires.

 

[fazeaway]

My suggestion is not to add the traction additive. Use the grade of fluid in the rear differential as required by Nissan.

since you didn't feel the problem with VDC off, maybe the shudder you feel is the VDC at work. you might be overdriving the traction limits of the tires.

The shudder is definitely the VDC doing it's job. I'm sure of that. I originally assumed it was the front end when I felt it in the steering wheel. Given the situation I was more concerned with keeping the car on the road to notice the slip light flickering when it first happened, lol.

I've had the problem with 2 different sets of tires now. The ones on it now were just put on last week. Same brand/model as the previous set. It happens worse now than it did with the tires I replaced. If it were traction limits wouldn't the old worn set have experienced the problem even worse than a brand new set?

I'm certainly not discounting that it could be the problem, just trying to make sense of it.

 

[Gilley]

The old tires may have had more dry grip because they had shorter tread blocks (less squirm) and more rubber on the road.

 

[fazeaway]

The old tires may have had more dry grip because they had shorter tread blocks (less squirm) and more rubber on the road.

True enough. The only other concern is that this problem didn't occur like this when I first put the previous set of tires on. It would rarely do it when turning left and it never use to occur when turning right.

Is it possible that tire pressure could be causing it? Could high pressure cause the tires to slip easier and low pressure cause too much grab and throw off the differential?

 

[thatguy]

Ok, so after checking the front end everything is absolutely fine up there.

After that I decided to find a nice curvy road to try and duplicate the problem. Low and behold there it was. This time I noticed the "slip" light flickering when it happens. Tried the same test with VDC off and it didn't do it once. Looks like the problem is actually in the rear end. The stuttering from the VDC was just enough to cause a shimmy and slow the car down.

The best I can figure is that the clutch(es) in the rear end are slipping.

I changed the fluid in the rear end and added some posi-trac additive. The fluid that was drained out looked perfectly fine, no grit or anything. Going to let the new fluid and additive work into the rear end. Hoping that will fix it. If not, any suggestions?

The stock LSD is a viscous type, goo not clutches.

From what I understand, the fluid that is drained from the differential is not the viscous goo used for the LSD. There is a separate silicon based fluid that is used for the goo. From what I have read that fluid is not serviceable.

 

[Gilley]

True enough. The only other concern is that this problem didn't occur like this when I first put the previous set of tires on. It would rarely do it when turning left and it never use to occur when turning right.

Is it possible that tire pressure could be causing it? Could high pressure cause the tires to slip easier and low pressure cause too much grab and throw off the differential?

Higher tire pressure will make the tire have les rolling resistance and friction.

 

[fazeaway]

Ok, an update.

I've been driving with the VDC off until I can figure out why it's acting up. Low and behold, even with VDC off, the car will "shudder" and slow down in a heavy corner. The car has been checked and the front end is fine. The only problem is the front tires are cupping pretty bad already. I've got new fronts on the way to try and see if that takes care of it. Could this be causing the problem?

Also, I bought the car used, '03 Coupe 6MT sport package. This may sound strange...but what color should the stock springs be? I'm starting to wonder if the previous owner had it lowered and if I'm in need of adjustable camber.

 

[thatguy]

If the tires have bad wear that usually indicates alignment is out.

not sure what color they supposed to be