Slip Differential Problems

[pdsigep79]

I recently put on a set of Falken Torque 5's with Toyo Proxes 4 tires. Since then my limited slip has come on mostly on the highway. I'm not going any faster than 70 and most of the time it's on a straight away. My slip keeps coming on and causing a lot of problems. I'm trying to avoid the $90 diagnostic fee at the dealership at all possible. The car won't accelerate and is going to get me rear-ended if it keeps up. Anybody got an idea what the problem might be? I did just recently add some higher performance break pads to cut down on break dust. The car only has 28k miles on it and I've owned it for 3 and 1/2 years.
Modified by pdsigep79 at 5:37 PM 5/29/2007

[evildky]

Welcome to Nico!

I'm pretty sure you're 3 yr 36k mile warranty should still cover any problems but I'm just not sure what exactly you're talking about?

the limited slip, found on all models above the base, simply makes bioth rear wheel turn at the same speed under a slip condition, IE hard acceleration off the line one wheel slips then the 2 lock up so you can get traction and go streight, some of the cars had the traction control which detects individual wheel speeds and when you are turing and one wheel locks, it applies less breaking force to that wheel and more to the others to help you regain contriol rather than loose it as the computer thinks you are about to, only serves to slow you down in turns when one wheel slips or locks, unless your racing it should not be an issue

so what exactly is going ion in your situation?

[pdsigep79]

The slip just randomly comes on when I'm driving. It's not off the line or anything. It's when I'm on the highway maintaining 60-70mph. It happens on straight aways and when the road turns. I never had the problem before when the same wheels and tires were on.

[evildky]

ok, your not really clarifying anything, your telling me that randomly, on the interstate the rear tires turn at the exact same speed?....and you think this is a problem?.... you are not expressing your problem in a way that I can help, the limited slip makes the back tires turn at the same speed, but only when one side slips, , if your going straight downt he road the lsd woudl have no casue to engage and if it did you would not notice as your traveling straight so the rear tires are already turning at the same speed

how about you stop addressing the symptom as your "slip coming on" and describe it as the symptoms taht you experience

[bmike818]

does your car come with VDC? what size tires did you put on your car? When you are on the freeway...what are you doing before the problem occurs..and does this happen only on the freeway...did you get TPMS on your new tires?

[350zSJD]

I venture to say this is a TPS problem, possibly from faulty install, they dropped a sensor, or tire size issue.

I think "have u seen the new cover sheet for the TPS reports?"

[C-Kwik]

I say it's a VDC issue. If the variance in tire size ratio between the front and rear tires, or perhaps even rear right to rear left, is too great, then the VDC will believe the tires are not obtaining proper traction. This is most common if you pick the wrong sized tires, but depending on the tire size you are working with, too much wear on one end can also create issues.

[C-Kwik]

I venture to say this is a TPS problem, possibly from faulty install, they dropped a sensor, or tire size issue.

I think "have u seen the new cover sheet for the TPS reports?"

I'm thinking you are referring to the TPMS (tire pressure monitoring system), not the TPS (throttle position sensor). Either way, the TPMS is an unlikely culprit as if it were broken or not there, you'ld get the low pressure light at worst. It would not cause the VDC to kick in.

BTW, a quick fix for the time being is to hit the VDC off button each time you start the car until you resolve it. This will at least keep the VDC from closing the throttle on you.

[pdsigep79]

The only problem is I don't have VDC. It never happened before just this last time the same wheels and tires were put back on. I did get them balanced again though. I thought that would help. Some one else did mention it might be the speed sensor being damaged somewhere along the way. I like having the slip on unless I want to take some one off the line or something. Any other ideas guys?

[bmike818]

I like having the slip on unless I want to take some one off the line or something.

I wanted to roast this guy on an onramp...im like okay VDC off-check...seatbelt-check..ready go......um I am not going anywhere..rpms are reaching redline and I am still not moving-oOOps whats that smelll-oh snaps its my tires I guess I got stuck peeling out.....darn you 350Z u so torquey- I say pay the $90..its only $90 to figure out whats wrong with your Z

[pdsigep79]

I'm sure i will pay it but I didn't want to b/c I'm going to end up paying a lot more money b/c the guy who put my wheels back on skrewed something up. He's a friend and did it as a favor so I can't try to make him pay for it. I just eating it.

[cory2081]

So, you must have traction control if you do not have VDC. It sounds like a bad sensor @ the wheel. I would visually inspect all sensors first, make sure that the connectors aren't loose or that the wiring isn't pinched or something. If it is making you feel that uncomfortable driving your Z on the highway, I suggest turning off the traction control, you really do not need it at highway speeds anyway.

[pdsigep79]

You're not the first person to say it's the wheel speed sensor. I might try to get that looked at first before I fork over the dough for the diagnostic test. I appreciate the input. I only like having it on during the rain and during the winter which is a mute point for quite a while. I just feel safer with the TPS on. I only take it off on straight aways. I paid for it so I'd like to use it. The 350Z is one of the most unsafe cars from a crash perspective so I need all the help I can get to avoid a crash. I'm not exactly a defensive driver. That's why I punked out and bought the auto. Other wise I would have totaled it or blown the engine by now with a manual.

[cory2081]

First off, you're welcome I'm glad to help. Second, the only time that the traction control does anything at all is from a stop. Unless you have a 500+hp Z, it will not break the tires loose at highway speeds, so, having the traction control on is kind of pointless. I was just saying that until you get it fixed, for your safety and the safety of others around you on the highway, turn it off. It's not like the Z has a huge traction problem anyway under normal driving conditions. I actually disabled traction control on my '03 Mach 1 b/c it was more dangerous to have it on. If I tried to pull out of a place quickly to beat traffic, the TCS would all but stall the car....WITH CARS COMING AT ME!! I'd rather burn a little rubber than the car stop midway in the road. I hate TCS, never seen one that worked worth a crap. I'm sure your problem is minor.