The Nissan Path

Hi,

just few days ago I faced strange low-frequency "bruuuum" vibration noise from drivetrain of my 2007 Nissan Pathfinder 4WD LE with Automatic transmission. The noise:
- is like I would suddenly drive onto ribbed raised side line on highway, you know, the one which produces low vibration noise when you cross it to warn driver he is driving off the track
- it appears only between 50 and 80 km/h (35 and 50 mph)
- it does not disappear if I brake or push gas pedal, if I am inside above speed
- VERY STRANGE is that vibration is not felt on steering wheel, nor on backseats....it seems to be just vibrating sound
- also STRANGE is that vibration PITCH is almost not changing with speed, so it has nothing to do with asphalt, wheels or tires

What ELSE I have noticed on my car:
- when standing on red light, for example, and having transmission in DRIVE position, standing on brake pedal...if I just SLIGHTLY let off brake pedal, not fully off, but just a bit, so vehicle might move for few inches...it does not "slide" forward smoothly, but is rather softly jumping forward, like being bumped forward sightly in steps; but this is very lightly sensed, not so rough
- also when I do STALE RPM TEST with brake pedal fully depressed and pushing gas to the floor for few seconds, the whole vehicle starts vibrating, with low noise bruuum and almost begins shaking a bit


Any idea?
Could this be TORQUE CONVERTER?
Or maybe one of transmissions?

UPDATE:
I found slight play within front propeller shaft, so I'll replace it.

The WEIRD thing I came accross are now both REAR drive axles, which have quite a lot of play at central diff side. See here, I filmed it:
https://www.youtube.com/watch?v=g8RIjsSB17k

What do you think - is it normal or not?

It's like driving over rumble strips, right?
Yeah, I had the exact same issue. Only at very specific speed/rev pairing and only between 60 and 70 km/h. It's a little cliche to ask, but have you checked for the coolant transmission contaminants?

Look up my topics. I ended up having my transmission replaced under warranty. The car is utterly transformed. There is absolutely no more jerking when shifting, or in stop/go traffic. All trans operations are ten times more smoothly and my fuel mileage improved significantly as well.

-edit-
I just noticed you have the diesel version. I am not sure if those have the same transmission. I would assume not. But the coolant part is probably the same, so perhaps in Europe they have similar transmission issues, even if the trans is different.

labsy wrote:UPDATE:
I found slight play within front propeller shaft, so I'll replace it.

The WEIRD thing I came accross are now both REAR drive axles, which have quite a lot of play at central diff side. See here, I filmed it:
https://www.youtube.com/watch?v=g8RIjsSB17k

What do you think - is it normal or not?

I don't know if it's normal or not, but it DOES seem like a LOT of play.

I have put new u joints in. Rotated and balanced tires. Changed atf and rear diff fluid and still have a slight vibration at speeds 50 and up

What else can I check

dawgn86 wrote:I have put new u joints in. Rotated and balanced tires. Changed atf and rear diff fluid and still have a slight vibration at speeds 50 and up

What else can I check

What about loose half-axles, like in my video 3 posts above? Especially rear axle - do they play like mine?
I do have vibration, but in my case it's definitely from u-joint on front driveshaft - will replace it in monday and see if it helps.

BTW...are FRONT U-joints 27x74,6 mm or some other dimension?

Wow. That don't look good. Were you moving the tire around?

dawgn86 wrote:Wow. That don't look good. Were you moving the tire around?

Actually, both shafts rear have the same play in any tire position Looks terrific, but seems to cause no noticeable wobble or vibrations...yet.
Curious about you guys...it's easy to check at the rear. Anybody with same loose half-axles?

Mine seem rock solid compared to the amount of play you have. I just got mine back from a major service and they have been checked on mine.