Rotational Driveline Noise: Transfer case?

2002. Tacoma 4x4. 5vzfe. 5 speed (R150f ?). ADD Transfer Case. 208xxx miles. 3inch lift. 285 tires

I am struggling to diagnose a rotational driveline noise that I now suspect is coming from the transfer case. Looking for advice/ help since i have zero experience with transfer cases.

Videos of noise:

https://youtu.be/vJNH0LxkkWY
https://youtu.be/hGPEWp9PJIo

Issue: Loud, rotational (bad)whirl noise with occasional metal chirp noise.
- Occurs at low and high driving speeds, 1st through 5th gear/ 10-70mph.
- Speed increases frequency of noise but has no effect on pitch or loudness.
- Occurs in 2hi, 2 low, 4hi, and 4low.
- No change found by turning, breaking, coasting, or gunning it.

Action:
- Removed rear propeller/ drive shaft assuming it was U joints and/or carrier bearing.
Result:
- Engaged 4hi and took on a fwd test drive...Noise persists, canceling out rear drive shaft components as issue.

Recently Replaced: (Last 20k no issues)
- all 4 wheel bearings
- both cv axles (napa)
- ECGS front differential needle bearing replacement
- Transfer case, front diff and rear diff fluid

Thoughts:
- decent amount of throw out bearing noise but doubtful this is THE problem, consistent transmission operation .
- Jacked up the rear end off the ground with no drive shaft connected... rear wheels spin freely with no noise. Rear diff pinion gear/ shaft has zero play.
- Zero play in transfer case output shaft flange
- Sound comes from back to middle.
- Decent weep in between trans and transfer cases

Transfer Case Thought/ Sound: - With rear driveshaft removed and engine running.
- I hear a rumble like bearing noise that is completely different from the problem noise, only while the truck is under simulated load///transfer case output spinning but no driveshaft.
- 2High/ 5th gear = Noise
- 2Low /5th gear = Noise
Second guessing myself/ will double check but...
- 2high/low, Transmission in neutral = NO NOISE
- Transmission in neutral and transfer case in neutral = NO Noise


So my thinking is a transfer case input shaft bearing, output shaft bearing, or maybe transfer case chain but the sound is more bearing than chain to me. When power is sent through the transmission to the transfer case there is a bad transfer case idle noise that may explain the loud noise while driving.

The kicker is the inconsistency, first day without rear driveshaft = noise, next day/week... drove for 4 days/ 40 miles without the rear driveshaft = NO noise at all, today, with no change in anything, drove 5 miles = Noise.

I appreciate yall taking the time to read this.

 

Bearing would be my guess, but you'll have to take it apart to figure out which one. You miiiiight be able to get close with a stethoscope though.

 

I made a post when I had to diagnose mine if you wanna check it out. some helpful ideas on it : https://www.tacomaworld.com/threads/odd-rubbing-noise-help-please.674152/

 

I'm responding to this thread because @SkunkMan17 thread is a bit messy and doesn't seem to have the same issue or resolution. I have nearly an identical sound as the second video in the original post in this thread. I also have my video here that may help: https://youtu.be/sdWEP3TDfWU

I talk about the driveshaft because think it's somewhat unbalanced because my carrier bearing is going out. I have rebuilt my driveshaft twice in two years. It's certainly not normal for the DS to go out that often so I'm assuming the T-Case might have something to do with it. The whining sound under acceleration is another problem that has come up. I got my transmission rebuilt 2 years ago and don't know how it would have gone bad again unless the T-Case was somehow "hurting" it. I understand there is a lot of movement under acceleration, I replaced the transmission mount two month ago

Here is another video that might help (I am moving the front driveshaft and not sure if the sound is normal, the wet spots around the plugs are from recently changing fluid): https://youtube.com/shorts/sI4mMpPeFc0?feature=share

My symptoms are nearly identical to @seehodgey although when I put transmission and T-Case in neutral it still makes noise.

Until I found this thread, I was under the assumption it was a wheel bearing or axle, although now I'm certainly second-guessing myself. Before I go out and buy an entire T-Case I want to make sure that's the problem. Does anyone have some insight?

I also just changed the T-Case fluid and it was pretty dirty:

 

Where is that metal chirp noise seem to come from?
When does it happen?
I had an undiagnosable chirp for the longest time that was finally found

But NOW there is a whirring noise.
Might be like yours IDK yet

 

I genuinely have NO idea. It has been squeaking for months. For the longest time I thought it was the driver side wheel bearing but nothing I see leads me to understand it’s a wheel bearing sound. The chirp got a little quieter when the grinding started but it’s still there…

 

Is this an automatic transmission?
The chirping in my truck was eventually found in the pilot bearing
The whirring noise it has now goes away when I push the clutch pedal all the way in
Rebuilt r150f from another truck

 

Okay, so this is interesting. I stuck my head out while driving and to my surprise, the sound was actually coming from the rear. I hooked up my $300 directional microphone to a GoPro and found some interesting things. I'm attaching the video here: https://youtu.be/h9quxMjyGGE

I pointed the mic at the left rear wheel first to see if it's a break bad or possibly a bearing like I originally thought. Then (with fingers crossed) I pointed it towards my rear diff to see if the sound was coming from there. In the video, it seems pretty obvious that it's coming from somewhere on the wheel. My left parking brake seems to be seized but it's been seized for years and I haven't noticed anything until about three months ago when the chirps started. I did have my rear drum brakes replaced about two months ago but that didn't do anything to the sound. I think this might be the rear wheel bearing. But from everything I've seen online, wheel bearings are more of a constant grind rather than rhythmic sounds.

Any thoughts?

 

I have an automatic transmission with J shift T-Case. Any way I can test or isolate the noise my configuration? Even though I found a lot of sound coming from my rear wheels I still have suspision about the T-Case.

 

Rear wheel bearings seemingly can fail and present with many different symptoms on these trucks, according to many reports on this website. For example mine never grinded either, but rather clunked whenever I turned the truck. Based upon that noise your driver side wheel is making, I think it is going to be your rear wheel bearing.

By the way, that directional microphone gadget is really awesome.

 

Thanks so much for the info! I’ll have to get it checked out formally by someone because I don’t have the skill set myself to self diagnose further than my own experiments.

Thanks! I’m a professional videographer so I just had it laying around came in handy for this exact purpose

 

Did you get this figured out?

 

Maybe I missed it but does you rig have a rear drive shaft center bearing? If so, check that.