Weird vibration/noise - still there

[JaimeZX]

Hey gang, I think before I mentioned the "angry goose" under my hood.

Just driving around town you don't hear it, but at about 40-45mph there's a very low, quiet sound.
By 50 you can definitely hear it.
At 55 you can hear it over the radio.
At 60 it's getting kind of loud.
I have never gone over 70. lol

The pitch also goes up a little, and a vibration gets more noticeable with speed, but the sound is always very low-frequency. It's like there's a 12" subwoofer under my feet, kind of.

Someone suggested it might be the air intake (which is cracked and I've duct-taped it). To test that theory, when I was on the highway yesterday I removed it and just ran an open throttle body for a few miles... the Angry Goose is still there.

So now I'm kind of at a loss.

* I still have the exhaust leak I need to fix, but that manifests itself as a PFFF PFFF PFFF sound under load... could it also simultaneously make a loud drone/vibration?

* I need to change the tranny fluid... I suspect it's still the original fill (so about 96,500 miles!) and that doesn't make for a happy tranny. Downshifts are a little abrupt sometimes. If it's a tranny issue, mebbe new fluid will help.

Any other ideas? Thoughts? Suggestions?

Thanks in advance!!

 

[JaimeZX]

Must be in the drivetrain. I put the rear end up on jack stands and had my wife run it up to about 65mph while I walked around the vehicle (sides and back, never in front!)

First, you can definitely hear the sound again, so I don't think it's in the suspension / U-joints / hubs / whatever. Plus I had the hood popped and the tranny fluid dipstick was vibrating like crazy.... so I think it must be in the transmission.

I figure the tranny fluid is probably 96k old... I was going to replace it but now I'm wondering if I should hold off and have a transmission place take a look at it?
The alternative would be to swap the fluid and filter, adjust the bands, and hope that improves things.
OTOH if it doesn't I'm out $100ish for synthetic fluid and a filter, plus the cost of tranny repairs.

Thoughts??

 

[JaimeZX]

I may have found the culprit.

https://www.youtube.com/watch?v=Llbsm0O_lOE

 

[JaimeZX]

Okay, pulled the drive shaft but I can't get the U-joint out!

I've removed the clips and pounded the joint down one way... but before the "bottom" cap is out far enough to remove, the actual U-joint has run into the inside of the drive shaft so I can't pound it any farther.

I tried going the other way to see if that would help, but it looks like the bearing caps are really tall on this U-joint. Not sure how to proceed... thoughts?

 

[JaimeZX]

So I've got all four caps on the new U-joint. Retaining clips in three. I have pounded the **** out of the last one but I can't get it down far enough to fit the clip in the slot. Is this going to be a problem, you think?

 

[MoparMagic'00]

yes it needs to be in there for sure... maybe wrong joint?

 

[JaimeZX]

It's been suggested I might have had a needle bearing come part way out of that cup and then flattened it with the pounding... :/

Anyway, I figured "what the hell" and just put it back on the truck. At least the angry sound from underneath seems to be gone in my "jack it up and have the wife run it up to ~75mph on jack stands while I listen underneath" test.
Will test drive it tomorrow... cognizant of the possible jacked bearing. Which may also explain why the joint moves more easily in one direction than the other...

 

[dodge dude94]

Huh....u-joint. That's new. Glad you've got it fixed tho.

 

[JaimeZX]

RE-replaced the U-joint, along with the one at the rear of the drive shaft... so two new U-joints on that thing. Went over to my buddy's garage and used a hydraulic press. Took about 20 minutes each and no smashed fingers this time. I recommend that method.

Took it up to about 65mph and no angry goose, so I'm very happy!