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

[SpecialDave]

Would rear diff make drone noise a bit like holed exhaust under load?


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[dom14]

Would rear diff make drone noise a bit like holed exhaust under load?


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This is what happened to the rear diff of my GQ, last year. It was the pinion bearing gone cactus.

https://www.youtube.com/watch?v=ljzu...ature=youtu.be

[dom14]

And yes, I forgot to mention, the noise always sounded like it was coming from the front, but actually it was the back. The noises and vibrations travel through the drivetrain and not so easy to pinpoint locations most of the time. It was a whirring noise in my case. No damage was done to the diff internals, even though I kept driving like that for few weeks.

[SpecialDave]

Ok - checked for play in the prop and drive shafts - none
Then after much percussive maintenance managed to open filler hole on rear diff - the fluid is prob 1cm below the filler hole. There was 1 very small metal filing on the plug. The fluid itself I'm unsure of what it should look like but here is a pic of what it looks like after a finger dip - keep in mind this is taken at 11pm, under the truck, in a servo, after 15 mins of belting a breaker bar with a weighted rubber mallet to release the plug...

image.jpg

Whilst doing all of this I remembered that a few weeks ago (maybe 4) I was inspecting and noticed the breather tube had disconnected at the top of the diff, I plugged it back in and it has stayed put but unsure how long it was off for..

And finally - here is a video I took last night where I am hoping you can hear the noise under load, when my seat isn't squeeking that is....


I'm thinking I might drain and redo the diff today or tomorrow morning - and pull the shaft off and inspect the bearings if possible at the time.

So I'm hoping these media insertions hell and that someone here may indeed know exactly what it is I should be doing or at least help me nail the source of the nose - I suspect diff somewhere but am not certain.

Cheers

Dg

[SpecialDave]

So diff oil replaced... 90 minutes in the middle of nowhere and cold but done..,what came out was pretty black'

And whilst the diff feels tighter the bloody noise is still there.

So I've checked tranny fluid, checked transfer case which was low and gear oil and now diff which I suspect had some water and replaced all with appropriate fluids and still happening so likely to be diff internals? Anything else?


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[SpecialDave]

Oh one more discovery - occurs only under load in all gears and only between about 1900 rpm and 3000 rpm?


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[4bye4]

Have you checked the universal joints. I have known a faulty one to make a buzzing noise.

[SpecialDave]

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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[SpecialDave]

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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[Robo]

why not try marking the position of rear prop shaft remove it and see if uni's are worn out.
could be the cause of noise as already pointed out.
maybe even stick it in 4x4 and go for a drive with rear prop removed.
you may isolate a cause