[dmako]

My MO has developed a vibration that can be felt through the steering wheel mostly at speeds between 60 - 70 MPH.

The vibration is produced by simply leting go of the gas for a second, then re-aplying presure to the gas pedal as to maintain speed.

If you coast, no vibration is felt. It seems that the small amount of torque causes the vibration.

AWD? CVT?

I had my dealer (after the first two, ' we can not repo the issue') investigate for two days and found nothing wrong as fas as suspension, motor mounts, wheel balance, tire rotation, or exhaust.

They basicly gave up, and I am off to seach for a new service dept.

Anyway, anyone encounter this?

 

[Kris]

Same here! And I thought it was my imagination! No vibration when coasting, slight gas and I feel the vibration through steering wheel as well as gas pedal, car body. It is only slight though is there. I haven't taken it to the dealer yet as I thought it was just my imagination....guess I will need to.

 

[mgthe3]

I've felt it.

I think a bunch of us did way back in 04 when I first started coming here. We attributed it to the T/C doing a waffle on locking up. It's like it is right at a torque limit for the rpm/speed.

I felt the same thing in electronic T/Cs in GM's.....at the same speed.

 

[Kris]

The T/C locks up at 18mph so it can't be that. Also the frequency of the vibration is I think close to 40 - 60 Hz, it is more likes grinding than vibration....at least that what I feel...

 

[mgthe3]

uh Hem.....I beg to differ...

I guess you would have to have had the experiance of a bad electronic T/C not unlocking to know the feel of a truely "locked" electronic T/C--the first thing that happens is that the engine stalls when you come to a stop--when an electronic T/C is locked--your engine output is directly coupled to the wheels.

No, the electronic T/C doesn't lock up at any MPH, it locks and unlocks according to the torque demand. It just happens to unlock at 18 MPH on coast , hence the push characteristic the Mo gives when slowing.
If you want to see what I mean, press the gas pedal hard while cruising 80. If it merely adjusted pulleys, the torque output to the wheels would be amazing and as linear as the press of the gas pedal---but it is not. The reason why is because the T/C unlocks for a couple of reasons, one of which is to protect the CVT. Lighten up a little from the hard press and what happens---the T/C locks up, you zoom off.
This is why I posted long ago about wishing that the engineers would have written a little tighter lockup algorithm for the T/C, it is a bit sloppy. I think the CVT could handle a lot more torque in that area. I mean really, you can burn rubber from a stop, why not let that torque be applied to the wheels at 80?

As I said before, a lot of us have experianced the waffling lockup vibration, and yes, it comes in at different speeds--and if you will notice, it happens at different torque demands because of going up hill, downhill or level stretches of the road.

 

[Kris]

Hm, on the second thought you might be right. I am not sure what is causing it but it is there and I feel it. And I think it does come at different speeds and I would agree with you, most likely at different torque demand. I wish something could be done about it. But what? My dealer is pretty good (I had very good experience recently with noise comming up from front suspention and alternator replacement) but I just do not want the hasle and wast time chasing something that is simply no fixable....at least at this time.

 

[dmako]

Going along with torque converter being the culprit.

The vibrations felt through the steering wheel for me are pretty constant. i.e. once they develop and they always do, it stays there until I alter the speed/torque by making a major change in gas pedal pressure. But then it come right back in most cases.

I would say during highway driving the issue is felt 90%+ of the time everyday for me. What ever is happening is happening all the time. Would think this would be an easy fix for Nissan, but that’s another story.

I also seem to be getting the same gas mileage, would the constant slipping of the T/C cause bad gas mileage? Also would it slipping cause the steering wheel to shake?

 

[Kris]

dmako,

steering wheel shake could be caused by unbalanced tires, out of round tires, bad alignment and number of other things. I do not believe TC could cause it. But I may be wrong.

In my case it is not "shake", it is vibration at a relatively high frequency. I would estimate it 20HZ, 30HZ and up.....and yes I can reproduce it anytime I want.

 

[dmako]

Yea my problem is felt through the steering wheel. If you just let your finger tips touch the wheel, you can feel it shaking back and forth. Kind of makes your hands go numb after awhile.

Now I agree with you about the wheels/tires yet Nissan for two days could not fix. They claimed that they felt the shake, but then it would go away so they could not pursue. Great!

The strange thing is as soon as I let go of the gas, the shaking stops. If it were tire wheel related I would think that the vibrations would continue. In order for my issue to occur, you have to be applying torque.

 

[Kris]

In order for my issue to occur, you have to be applying torque.

same here............

transfer case? Diff? Joints?

 

[dmako]

I'm thinking transfer case.

While I can't say for sure, it seems like my problem started right after they rotated my tires. I was so sure that my tires were out of balance that when I brought the car in for the next service I mentioned it.

Thats how this problem 'seemed' to get started. But swapping the ties back has no effect i.e. the damage is done.

My guess is that the change in tire diameter caused by the tire rotation broke/changed something.

I had this happen in my old Grand Cherokee but the tire wear was very bad in that case and it was an old Quadra drive. Had issue when turning the GC.

 

[Kris]

Interesting observation. I think my problem started when I put Yokohama Geolandars and was very pronounced with those tires. Swapping back to GY improved situation a lot. I cannot see any logics in it……at park and neutral engine revs nicely and do not feel any vibrations. Coasting – no vibrations, apply torque, low though, and here it is! But why changing tires would affect it? Go figure……

 

[Gonzo]

Silly question but are you describing the "lugging" than can occur at lower RPM? I thinking not since you said you were on the high way but thought I would ask.

 

[Kris]

I am talking speeds 50 - 70 mph.....

 

[dmako]

No, this is encountered (in my case) at hiway speeds 60 - 70+.

Although I have had it happen at 40 - 45MPH but not as often, but then again I do mostly hiway driving.

Silly question but are you describing the "lugging" than can occur at lower RPM? I thinking not since you said you were on the high way but thought I would ask.

 

[mgthe3]

I'll have to see if it actually makes my steering wheel shake.
I can make it do it at will as well. It usually occurrs at around 70, but I have had it happen at different speeds, 70 being the most memorable.

If it is steering wheel shimmy, it is obviously not the T/C. If this is the case....sorry I commented on the T/C.

 

[dmako]

Yes please check, and don't be sorry for trying to help.

I'll have to see if it actually makes my steering wheel shake.
I can make it do it at will as well. It usually occurrs at around 70, but I have had it happen at different speeds, 70 being the most memorable.

If it is steering wheel shimmy, it is obviously not the T/C. If this is the case....sorry I commented on the T/C.

 

[mgthe3]

I have been meaning to update this thread but it is kinda hard to find.

Yes, I get the vibration below ~1900 rpm.
Yesterday I noticed it at 1400 during heavy traffic under light accelleration. When I goosed it and unlocked the TQ--it went away.
I am sure that it is the lugging phenomena I have experianced with two other makes of vehicles: it has only happened on the ones with electronic torque converters that lock up.

It was very subtle in the steering wheel--more in the butt-O-meter.

It could be something as simple as a slightly clogged injector making it lug at 1900...and it doesn't do it every time. I have seen this symptom rectified by plug changes in other vehicles....although I wouldn't recommend getting them changed in the Mo--would cost you a mint comparatively.

 

[Kris]

mgthe3

I think you described exactly what I feel....it is a little anoying but I can live with it....let's hope nothing is going to break....

 

[mgthe3]

naaa, I don't think what you and I are experiancing is eminent breakage, I had a vehicle do it for over 60k miles--only when cold though and not all of the time.
I think it is a nature of the beast thing since I have experianced it on other vehicles. Electronic TQ's are cool, save ya lots of gas--but transmit even the slightest b itch from your engine.