Hi, I am trying to diagnose this noise in my tranny without having to first rip everything apart. I have a 2000 dakota with a 4.7l and a manual NV3500, in neutral as shown in the video there is a vibrating / ticking / bearing noise which also exists through each gear when under load. I have read other posts but nothing that described the noise as similar to this. I am leaning towards either pilot bearing or input shaft bearing has anyone heard anything like this? thanks

 

You can rule out the pilot bearing if the clutch is out. The flywheel and input shaft are rotating at the same speed.

It does sound like bearing noise.

What fluid are you running in it? When did you change it last?

 

Yeah that makes sense about the pilot bearing. I just recently (about 4000km) ago replaced my tranny fluid with royal purple sychnomesh. However the noise existed before that as well. There was quite a mound of filings on the magnet maybe the previous owner really beat on the tranny and the filings wore out the bearings?

 

In fact here is a picture of the magnet

 

Yeah, that's pretty nasty looking, glad you changed out the fluid.

Do you hear any noise, clutch in, with the transmission in gear? That way the input shaft isn't spinning.

 

No noise at all when clutch is in. The last couple revs in video are with the clutch in.

 

With the transfer case in neutral, the transmission in any gear, and the clutch out are you making noise when NOT moving?

 

Yeah noise persists with transfer case in neutral in all gears.. slightly quiter in 3rd and 4th but still there. I am also getting a lot of clutch shuddering upon engaging as well as the noise tends to coincide with the vibration. Hard to hear on video but it almost sounds like something hitting something else or vibrating due to not being balanced... flywheel? faulty clutch disc? The previous owner said he put a new clutch in... which is bothersome because I have seen the quality of other work done to truck...

 

I'm with you on the clutch disc, maybe a finger problem, who knows.

Looks like you may have to pull the tranny anyways.

 

Not much of a stick guy so pardon the ignorance, but if it was a clutch/pressure plate issue, wouldnt it go away when the trans is engaged and the clutch is loaded, and exist when it is all unloaded?

I didn't see anything above where you had the clutch engaged but trans in neutral, case in gear. That would tell us if it is input shaft or output shaft (since one would be moving and the other not).

Two opposing theories:

1) This makes me think output shaft bearing or possibly an oiling issue. As the output shaft speed increases, more oil gets slung around and the shaft starts "hovering" inside a loose bearing.

We had the latter happen in our powerglide at the thanksgiving race- output shaft bushing came unseated from the case, and the only thing supporting the planetary assembly was the input shaft bearing and the transmission output slip yoke/seal. It didn't vibrate at all in low since the band was holding the drum, but as the RPM's climbed in high gear, the vibration went decreasingly noticable.

2) This makes me think input shaft bearing, because as you go up in the gears, you're placing more and more resistance against the input shaft, which will make it harmonisize less in a loose bearing.