Another mystery noise. Deep bass sound on decel. (U-Joint?)

[oreogaborio]

I've got a really weird noise on decel. I first heard it only when doing 80mph+ and let off the gas, but now it does it at much lower speeds.

If let off the gas doing more than 45mph, I begin to hear a very deep "bass" sound, almost like wind buffeting, but it's not that. It's kind of like when you're driving on a rumble strip, but not as loud or "jagged" of a sound. It's just a smooth deep bass sound and it only goes away when I either stop decelerating or decelerate down below about 35mph.

I can put the transmission in neutral, rev the motor or even downshift and it does not change the pitch or volume.

I have not tried it in 4WH yet. Only 2WD.

Any ideas?

'05 SE with 91,500 miles on it. The only thing I've changed from stock is a transmission cooler bypass and a bug deflector... other than that it's all stock.

[disallow]

u-joint

[oreogaborio]

Yeah... That's what I was thinking.

Sounds like a DIY project with the right tools?

[disallow]

Yeah... That's what I was thinking.

That a DIY project with the right tools?

Yup. To check them, start with the rear shaft. Disconnect from the flange and rotate the u-joint around. Any abnormal play, or stiffness/seizedness will indicate where the problem is. If it seems good, move on to the front. I would drop the whole shaft here. Also check the shafts for damage.

Be careful not to round out the nuts and bolts, or you will have to get new ones. Lots of penetrating oil should help, and also this assumes that nobody else has ever played with them to round them out.

Once you find your culprit, a fine tipped flathead screwdriver, a BFH, the right size (hardened) socket, and a hard surface are required to get the job done. Plenty of tutorials on the net to walk you through it. I haven't actually done it, but I watched my neighbour wail on my driveshaft for about 45 minutes to get it to pop out.

In my case, the needle bearings were all rusty and seized. It was the rear u-joint on the rear driveshaft.

t

[oreogaborio]

Thanks Terry. Gonna see if I can find any good tutorials. Haven't spotted any yet, but when I do I'll post up for others.

I did just find this thread though & it had a few good posts - http://www.thenissanpath.com/viewtopic. ... joints+diy

[oreogaborio]

Nice. Think I found a couple of winners.


http://www.thenewx.org/forum/showthread.php?t=34245

http://www.thenewx.org/forum/showthread.php?t=19209

[oreogaborio]

Front Shaft Front Position
http://shop.advanceautoparts.com/webapp ... 273620____

Rear Shaft Front Position
http://shop.advanceautoparts.com/webapp ... 269915____

Can't find Front Shaft Rear Position or Rear Shaft Rear Position. Same parts?

EDIT: Comparing part numbers I found on Napaonline.com, yes, they're the same part numbers on either end of the drive shafts.

[volvite]

Good luck. I just had to do this on my 99 Jeep and it took a lot, and I mean a lot of power with a big hammer to get them to move out. All three ujoints.

[Taavi]

I did front shaft u-joints few months ago. It is an easy work,there is nothing to worry about. If you have a one bad u-joint then replace both ends.
I used hammer, flat ended screwdriver for u-joints and 13-14mm wrenches for removing the shaft.

Do not forget to make marks becouse you have to put it back together as it was. Otherwise there is good chance to get shaft out of balance.

Rear and front shaft u-joints are different but bohts ends of shaft are same.
http://www.ladu24.ee/et/ladu2/19182/7026,187942

[oreogaborio]

Replaced the front U Joints today. The noise is noticeably quieter on decel now but I still hear it ever so slightly.

The noise is louder when riding in 4WD and it still requires slowing down and turning to get it to pop back into 2WD.

I would have thought that would point more towards the fronts, but I'm going to do the rear joints soon as well at some point... unfortunately I'm pretty busy for the next few weeks so I don't know when that's going to be.

[ShipFixer]

My front drive shaft was bent when one of it's U-joints went out. The noise didn't go away because of that. You might still have a problem.

One of the steps in the service manual when replacing the joints is to check the shaft for straightness...

[oreogaborio]

Can't imagine that's the case here. When I say it's still there "ever so slightly" I mean it's barely even audible unless you're really trying to hear it. It's really only noticeable in 4WD now. Had it up to 85 (in 2wd) with zero issues.

[ShipFixer]

Can't imagine that's the case here. When I say it's still there "ever so slightly" I mean it's barely even audible unless you're really trying to hear it. It's really only noticeable in 4WD now. Had it up to 85 with zero issues.

Oh. 4WD on pavement?

That *should* give you a rumbling noise I once let some six year olds play in my truck and didn't notice they'd switched the transfer case over. Thought I had another U joint gone bad!

[oreogaborio]

That's what you get for letting 6 year olds drive your truck jk



And in other news.... Bet I found the source

[oreogaborio]

Just did the rear U joints. A couple of them were pretty much full of needle bearing dust. Sound is virtually unnoticeable now. I didn't replace the drive shaft balancing weight just yet but at some point I'll get back under there and stick a wheel weight on there or something and JB weld it.