Thread: What’s this noise? [emoji51]

Have you checked all your UJs?

REgards PhilipA

If UJs are in good condition ...

Originally Posted by Colmoore

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Transfer in neutral and run through gears, no noise. Maybe not transfer case then.

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Not necessarily.

Sounds like transfer box bearing(of some type). Too many bearings to list here.
Could be drive yoke bearings or something relatively easy to do like that.

I'll tell 'ya my 'saga' tho.
Got my D1 3 years ago, and 2 months in I was driving on a level part of a freeway, just cruising easily, no load, just light throttle .. and BANG! .. drivetrain bang. Scared all the brown stuff out of me, as it was unexpected.
Slowed down, nothing obvious seemed wrong, just needed a little power to pull up a slight hill to the side of a safe area, but no drive. engine revs, but not the drive I needed to get to the spot I'd decided to pull up onto.
AH! panic no set in, about 10PM, miles from an easy recovery. My D1 is auto too. Tried all trans gears manually .. nothing, but could hear a fain 'grinding' noise. Ah! Hi/Lo lever had set itself to neutral whilst on the move(90-ish k/h) hence the bang .. etc.
No worries, put it back into Hi, drive off .. no worries.
As I gently accelerate, slowly getting up to about 60k/h I could hear a faint whine. At about 60 fain whine turns to obvious whine noise. By 80 k/h now obvious whine noise is ear splitting loud obnoxious and (I know will be) painful on the ears over time. Had about 1 1/2 hrs to get home. Decided to take back rods home(off the freeway) and just sit on about 60-70 ish on as many roads as I could, if I had to 80 on the freeway sections, but only if I had too. Over 80 sounded unbearable and maybe like it'd overcook and lose drive all together.
Anyhow, got home, borrowed bros car for a couple days(D1 is my one and only daily). Checked oil level in transfer, all good. dropped and refilled mainly to see if any metal bits within, nothing, and oil still relatively clean(ie. not old and unserviced).
Bugga.
Checked transfer output flanges for play, nothing. Just the usual rotational slack due to centre diff slack. Bugga.. nothing obvious and easy to replace, so more than likely some internal bearing must have just 'popped' or done it's worn out thing.

Looked for a rebuilt, swap out transfer box deal all over the net as I could, one bloke in bayswater had none, 4WD mob up in Maitland had one, and reckon they could do it in a day for me. I had a weekend to kill, so decided to do that.
ie. drove Melb-Maitland to get them to changeover the transfer box .. basically ASAP. They didn't have time to fully strip it while I was there(about 8 hrs all up) but the young chap reckons he could feel a loose bearing(can't recall which one now tho).

Bearing survived the 1000+ klm trip, definitely my worst ever drive anywhere .. ever!... screaming bearing from about 80 k/h just finally wore me down. Did the drive overnight to avoid traffic, I didn't cause truckies any issues beign a mobile chicane.
Drive home with reco transfer case was sublime tho.

Your whiny sound and conditions sounds very much like my issue with my T/fer box, but note that my D1 was auto too, not manual.

I'm thinking that if you have transfer in neutral and run through gears and no noise, then most lilkely the output shaft(bearings) could be fine, but this won't eliminate the intermediate shaft bearings, nor any (centre)diff bush/bearings.

Also wouldn't eliminate (axle) diffs either. Obvious that the noise is under load only. To eliminate the axle diffs, you'd have to test each one on it's own.
But more lilekly you should be able to hear obvious noise from one end or another. But to be sure, you need to remove the drive shafts one at a time and drive it with centre diff locked up. This way you drive with load only on the one axle(and diff) at a time.
Does the level of noise change. While driveshafts are out check the UJs more so for stiffness in the UJs movement. Old UJs will more probably be a little loose, new ones a little more stiff, but smooth .. no notchy movement.

Have you checked transfer for oil level? hard to fill from a bottle, so a pump bottle of some kind helps there, fill level is when oil starts to pour out of the filler plug.