Funny Sound

[1Bad4Runner]

Right after I lifted my truck I started to get a vibration in the back of my truck, I thought it was the U-joint so I looked under and they were fine.
I left it for another week because the garage was taken up by my fathers truck and the vibration has gotten a little worse and sounds kind of like a rattling when you let off of the gas. I was thinking maybe the output bearing in the t-case, anyone have any ideas?

[lilbuddy]

5 bucks says the Pinion Nut is loose. Either that or you have a broken ring gear. I was coming back from the Con and GENO was in front of me and I could hear it while we were driving, stopped, tightend it. Got back to Chico, he undid the third and found out that the ring gear had some broken teeth off of it.

[1Bad4Runner]

its never been wheeled before though But I do spin the tires sometimes.
I'll have to check the oil and see if there are metal chunks.
Thanks Lilbuddy!

[KWP]

 I was thinking U joint. I had the same problem in my 4runner at the tcase end. My mistake was I didn't check it in time and on my way to work one day the U joint came apart going down the highway at about 70. Not a very pleasant experience

[1Bad4Runner]

Ouch! Thats sucks.
I already checked the U-joint, I think Lilbuddy might be right, it does sound like a kind of grinding noise. I hope thats what it is since I am replacing the gears this week.

[Rocksurfer]

5 bucks says the Pinion Nut is loose. Either that or you have a broken ring gear. I was coming back from the Con and GENO was in front of me and I could hear it while we were driving, stopped, tightend it. Got back to Chico, he undid the third and found out that the ring gear had some broken teeth off of it.

I would agree with this, I had this happen to me a long time ago. When you are under acceleration the load will force the pinion up and off the carrier, when you are decelerating it will be driven into the carrier creating a low growling noise and a vibration.

[1Bad4Runner]

The pinion nut has never been off of the truck before, I looked at it and the lock is still in place and it all seems tight. Would I be able to tell it is loose? The pinion turns about 1/2" back and forth, I though this seemed back, but I talked to some people and they said for an older truck that is alright. What do you guys think?

[KWP]

The pinion nut has never been off of the truck before, I looked at it and the lock is still in place and it all seems tight. Would I be able to tell it is loose? The pinion turns about 1/2" back and forth, I though this seemed back, but I talked to some people and they said for an older truck that is alright. What do you guys think?

That sounds about right. It will have some movement.

[1Bad4Runner]

Ok, well... I guess I will find out soon anyways, since my gear install kits should be in on Tuesday and then I will be adding some 5.29's to the truck and hope it sounds alright.

Thanks for the help, I'll update if it goes away or stays.