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

[SpecialDave]

Hi all,

The history is my 02 GU 4.8 auto duel fuel seemed to have a slow minor leak. Turns out when I looked beneath it was a bit bigger than that. She's developed a whine and what sounds like a holed exhaust noise.mbut only under load in drive.. If I'm in neutral and rev her the noise is gone, if I'm in drive and coasting it's gone. If it's cold, the noise isn't there but as soon as it warms up above say 60-70 in the transmission it starts.

I'll attempt to post pic of where I think the leak has been from. I did check my transmission fluid levels after purchasing the Nissan dip stick (anyone out my way ever wants to borrow pm me) and aside from appearing to have green transmission fluid the levels seemed appropriate at both hot and cold checks so my leak is not transmission.this is where I think the leak is sourced...

image.jpg

I'll try and get her up on stands and specifically identify the noise but short of that I'm keen to diagnose or at least shortlist cause.

Based on the load occurrence and temperature factors it must be driveline gear changes seem fine in both 2 and 4wd. Like I said it sounds like when one of the bolts between exhaust sections mid vehicle went missing and thee was a leak but there's no obvious hole...

Anyone had same? Amy suggestions?

Maybe a bearing that's activated In drive under load?
It's not the chain in transfer case as no grinding or clunking?
Shaft?
Diff although I don't think it is but could it be?

There seems to be some loss of power when this is occurring but not slipping type just general inability to get power to wheels?

Thanks for reviewing - frustrated but hopeful not a terminal issue!

Dave

[garett]

checked the level in your transfer ? sounds like it might be a low oil level ... my gear box did something similar when it was low on oil. the transfer i think is separate from your transmission.

[SpecialDave]

Thanks good sir... Will go about doing so tomorrow morning. Stay tuned for follow up question should my search for doing so proves fruitless...

[SpecialDave]

So lots of inspecting and research, it took a suspicion and mounting my gopro under the canyonero to see something a bit sus - my front prop shaft is full time engaged!

Is this something to do with auto locks playing up?

[threedogs]

You can manualize the hubs if you want, have a search .
Easy enough to do from what I hear

[SpecialDave]

MudRunner I'll pm you as well I read the following and am keen to see what you did to resolve the issue as I suspect it's what I have happening but am disinclined to convert my autos to manual unless absolutely necessary...

I would remove the front drive shaft and go for a drive and see if it is still there???

I have had a similar type of thing.... I think? It turned out my Auto hubs had not disengaged and although I was in 2wd I was still locked in 4wd. Worth a shot. You would not likely feel this vibe offroad so may not notice.

It would take 5 minutes to remove the front shaft and worth a drive, you could be chasing a ghost mate.

[SpecialDave]

Transfer case - took out just over 1lt of gear oil which was black and a very small amount of metal filings on magnet and replaced with semi synthetic Penrite atf -instant improvement - still a bit of a noise but could be diff so will do both next weekend. I've degreased and cleared the entire transmission and tfer case so I'll be able to spot where any leak is occuring. Haven't checked yet if auto hubs disengaged - stay tuned

[dom14]

At one stage, I wanted to convert my manual hubs to auto, thinking it's a PITA to get out of the car all the time to engage them.
Then I read all the postings here(well, not all of them of course ), and decided to stay happy with the manual hubs I have.
So, how did you go with disconnecting the front drive shaft and testing to see if it's the auto hub?

[SpecialDave]

To be done with the drive shaft- ran out of time as have little one...

Any tips on the process - remove front drive shaft, go for drive?


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[dom14]

To be done with the drive shaft- ran out of time as have little one...

Any tips on the process - remove front drive shaft, go for drive?


Sent from my iPhone using Tapatalk

That's probably a good idea.