Diagnosis help - noise under load sounds like transmission but....

[dom14]

Update - front prop shaft removed and I suspect for the first time ever. Noise still there - but far out the steering is now light so I may have one or 2 locked hubs as well which I'll jack up later and check - the unis seem ok in situ but short of pulling the tail shaft off won't truly be able to tell. I'm hoisting it up later today and going to see if I can replicate with it in the air and zoom in on the source....but noise is not from forward of the tfer case....


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Well, obviously you have a front end issue as well, if removing the front shaft eased up the steering.
Find out the front hubs aren't locked by jacking up the front end and turning each wheel and see if the diff pinion/front shaft turns.
Gentle turning as well as sudden jerking turning of the wheel might help diagnosing possible intermittent lockup of a bad auto hub.

Have you checked the rear uni joint for any play? Make sure a wheel is chocked up, not in gear and the hand brake is not on when you do that. Jack up the rear wheels and try to twist and push and pull the uni joint. Jacking up the rear wheels may not be important, but I reckon it can help with the feeling.
Seeing little bit of metal filing on the diff bung is not necessarily a bad thing.
Another thing came to my mind is that make sure the diff breather hose(both front and back) are not blocked. When the diff filler bung is out, blowing into the breather hose is a good way to find whether it's blocked or not. Blocked diff breathers can cause all kind of dramas, including oil seal failure and leaking diff oil and leaving it dry eventually. The blockage could be either inside the rubber hose or the diff breather hole or both.
Also make sure you use the proper LSD oil for the diff. Rear diff is definitely LSD. Front can be either LSD or open, depending on the history of the vehicle.
Considering what you've posted so far, I'm bit suspicious of the transfer and the gearbox, but you need to rule out the rear diff & uni joint first, 'cos AFAIK, they are a pretty common cause of drive train noise. Should I say rear uni joint(s)? See if the uni joints are in good overall look or whether they look like covered in crap. They need greasing as well, but that's out of question if one of them is already worn out.
BTW, uni joints are really happy when you mark them before removing and put back in exactly the same way it was before.
They can produce noises that wasnt there before when you do otherwise.
So, remove front and test drive(you've already done that)
Remove rear and test drive with front drive.

[dom14]

So front left auto is not disengaging and that in turn has meant constant 4wd through the transfer case which is where I'm guessing I have something with worn down teeth so it looks like I'll be leaving the front prop shaft off to avoid further damage and then investigating if I can diy repair or mechanic and then do a auto hub to manual conversion... Man that sucks!


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It's better to try one thing at a time, while eliminating the suspected areas as the cause of the noise.
Transfer case is isolated when you're not in 4wd or low gear mode, right?
So, that should be another logical approach to elimination.

[dom14]

It's pretty hard to hear/diagnose noises from videos.

Watch these videos that I've posted during my rear diff drama.
In my case, the noise was quite prominent when coasting.
There's nothing you can really clearly hear in the video, but for me inside the car, it was
like a helicopter inside the vehicle.
https://www.youtube.com/watch?v=8mF-...ature=youtu.be
https://www.youtube.com/watch?v=6FXJ...ature=youtu.be
https://www.youtube.com/watch?v=7YxzbdrNIeI
The humming, whirring noise is apparent when I was coasting the vehicle in the video, but hard to distinguish it from a plethora of other regular noises of a car. You need special kind of microphones to video record subtle noises. In my case, it was noisy while coasting most of the time, kinda classic worn rear diff pinion bearing symptom in early stages.(In the end, It got to the point it was making the noise when accelerating as well) I reckon there can be other things that make similar symptoms, like gearbox bearing issues.
In your case, coasting doesn't produce or aggravate the noise. That's kinda good news(or bad news, depend on actual location of the actual problem).

[SpecialDave]

Thanks all so I had jacked up each front wheel and gave it a spin, the right front no prob but the left one spins the diff so even if I'm in 2wd it's turning the front prop shaft in the transfer case yeah?

Or is there some sort of mechanism in the transfer case that needs to be engaged? Ok just read the service manual to better understand and unless I engage the clutch and gear in then it will be spinning in neutral from the front but may have stressed the bearing...

I'll check the unis and breathers as described and hopefully isolate this. I'll also figure out if I can unlock the left hub before I make them into manuals..,,

Getting urgent now as looks like I may need to live in the girl for a while as wife just left me but I'm moving out so the kids and her will have a roof.... Fml


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[SpecialDave]

Is there a way to unlock a stuck hub without doing a conversion?


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[dom14]

Is there a way to unlock a stuck hub without doing a conversion?


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Mine is manual, mate. I haven't had to deal with auto hubs so far. Somebody who knows about it need to post some advice about that.
I would suggest downloading the Haynes and factory manual form here and read it through and start dismantling the auto hub assembly. May be it just need some lubrication, grease to engage, disengage properly.

[dom14]

Thanks all so I had jacked up each front wheel and gave it a spin, the right front no prob but the left one spins the diff so even if I'm in 2wd it's turning the front prop shaft in the transfer case yeah?

Or is there some sort of mechanism in the transfer case that needs to be engaged? Ok just read the service manual to better understand and unless I engage the clutch and gear in then it will be spinning in neutral from the front but may have stressed the bearing...

I'll check the unis and breathers as described and hopefully isolate this. I'll also figure out if I can unlock the left hub before I make them into manuals..,,

Getting urgent now as looks like I may need to live in the girl for a while as wife just left me but I'm moving out so the kids and her will have a roof.... Fml


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Sorry mate. Sounds like a lot going on there, not just the fourby. May be you wanna open a thread in the area where we discuss such stuff?!

From the description above, it appears you have a stuck hub on one side. That may be your problem.
While waiting for somebody to post some good advice on that, skim through the repair manuals.

[SpecialDave]

You're a good egg dom14...


Appreciate the advice. I'm going to pull the hub off and inspect clean and re grease the locked hub. I'll also reinstall front prop shaft and then going to check rear uni I as prescribed and while I'm underneath all coved in dirt I may as well check the breathers...

I sincerely appreciate you taking the time out to give good advice mate. Owe you a few beers!

[SpecialDave]

***1 of the multiple issues and root cause of major issue solved***

Before work this morning I replaced the front prop shaft in exactly the same place it was - I then jacked up and put a stand under my left front and , removed the stuck autolock hub (front left) and inspected. It was caked in grease and it had grit in it - too much grease as far as i can tell. i removed grease, cleaned it up and applied new more appropriate levels of grease and tested. Still locked.

So i then went about the very simple task of removing autolocking mechanism, not kidding, it is easy as! during that process when locking the hub whilst off i noted that despite the nut being turned by my tyre iron, nothing internally seemed to move..... To verify my suspicion i remounted the hub and fastened with a couple of the hex head bolts and gave the wheel a spin, dutifully the front diff and replaced prop shaft immediately followed suit.

Remove offending hub, swear a bit, look at it in an angry tone and refer to the fa section of the service book. So i get how it works but obviously mine is stuck in lock regardless of the selection made. did some gentle poking and prodding and looking and swearing some more before i had the epiphany of last resort - last resort is when you are prepared to potentially damage the offending part and require spending money to replace.

So i put the hub on a by now very greasy rag, actually is was more of a pool of grease with a rag in it, exterior down, went to the toolbox, and pulled out the trusty weighted rubber mallet. it was time for percussive maintenance because aside from temperature all i could reasonably do to unstick a stuck sticky bit was force. And metal on metal type force through a metal hammer or prying posed to much risk of damage.

I let loose a couple (ok 3) very hefty but accurate strikes and heard the most pleasing sound, a sudden release of mechanical parts, insert fingers into centre of hub (mind you auto mechanism still off) and it spun inside the hub i was holding ie it had popped free. Remove more dirty grease and note the gritty non metal pieces. Draw conclusion that the grease had become gritty and fouled and this grittiness has caused the hub to lock on.

i then put the auto mechanism back on exactly where it came from (I mark all components i remove for the reverse rebuild) . I then put said hub on wheel again and unlocked again and spun the wheel and OMFG it worked... the hub spun freely. I then put hub on manual and it locked, I repeated many times and on each time the hub worked as it should, being now late for work was overshadowed by a small success.

SO - Was the front hub or both hubs locked? Yes one of them had jammed. As a result it had continuously rotated the prop shaft inside the transfer case however without selecting any 4x (H or L) this should not cause too much trauma but... the pre-existing oil leak from transfer case somewhere coupled with the increased friction temperature has quite possibly had an impact on the tfer internals.

So either later or early am tomorrow I will be doing the rear uni inspection and taking a good look at the unis and the bearings on rear diff front and transfer case out to shaft and also opening fill window and taking a peak.....

I'm pretty certain i've discovered the source (ie the locked hub) of the stresses that have resulted in; power loss and droning noise between 2k and 3k revs in all gears only under load. past 3k no problem with power getting down in all gears so i now suspect a bearing ether in the unis or the aforementioned shaft to diff or shaft to transmission/transfer areas.

So a leak to find and fix, a noise and low power in rev range remain the issues. But i still have working auto hubs and now the experience to be able to do that fix anywhere as long as i have tools!

I did manage a sneak peak and the rear shaft, from side on it appears to be spinning with a little eliptical wobble at the transmisson end..

stay tuned

DG

[4bye4]

Never had any experience with the hubs - but love this write up. I wish I had that sense of humour when I pressure washed my engine and had to replace the alternator.