Thud noise

[90jurassic2]

I have an extended cab, 4.0, M5OD. Recently when I've been driving I can hear a thud noise. It hasn't been that bad, but today I went to take my truck for a little stroll down main street and the thud/clunk noise got worse. It doesn't make the noise when I put the clutch in, but when I start driving again it gets just as bad. It does not speed up with the RPM's, but goes with how fast I'm going. I've looked into it being my carrier bearing, but when I press in the clutch the noise should still be there. I only have 14 more days of driving this truck, so I'm not really looking into getting my transmission rebuilt and all that stuff. I just need help finding out what this noise is, and if I'll die while driving my truck.



I've already tried searching, nothing helped.

 

[black_demon69]

does it happen over bumps?
is sound on one side of the truck? if so check the radius arm bushings.

u joints might cause a vibration or a thunk just when first applying torque to drive line

 

[90jurassic2]

It doesn't just happen over bumps. It's in the middle of the truck, under the tranny hump. My buddies have told me it could be bad u-joints/carrier bearing. Just picked them up, gonna put them in tonight. Hopefully that'll fix it.

 

[90jurassic2]

Got new u-joints on it. Didn't fix the problem. It feels like its hitting right underneath the seats, but when I look, it doesn't look like the drive line isn't hitting anything. I read that the yoke could be kissing something, but that doesn't seem to happen. The noise happens in reverse and going forward. I will put it in neutral and I can still hear the clunk noise, but it's not as loud as when I gas it. I have to report in on Tuesday and don't want to be in trouble with my command. Does anyone else have any ideas at all?

 

[90jurassic2]

I've narrowed it down to being something in my rear end. Probably should put some fluid in it....

 

[90jurassic2]

I put fluid in, still making the noise though. Any ideas what it is?

 

[Dune Runner]

Tranny mount?

 

[90jurassic2]

I haven't even looked at those... I replaced them about 5 months ago though, and 3 of those months I was at boot camp. So I don't think they should be out. I just dropped my truck off at the shop. So we'll see what they have to say.

 

[feellnfroggy]

either the pinion bearings are shot (unlikely) or the split driveshaft carrier is bad.

 

[90jurassic2]

The gears were shot in the diff. Time to do my SAS...