yea sorry, took me a couple of days, well i changed the oil in the diffs and tranfer case to 85/140, i also completly flushed the tranny and fitted new filter and pan gasket, and it has made a considerable difference to the noise levels, it has quieted the whining on slow acceloration (20 kph to 30 or 40kph) which was the loudest and seemed to drone through the whole body, i can still hear it , but no where near as bad, the high pitched whine/whistle is still there that grows louder and more high pitched with road speed (at 50kph sounds like a constant whistle but is nearly gone at 60kph) but again that is noticably quieter, so over all ,a good result. so the way i see it, my options are, 1, put up with it , 2 , put a straight through exhaust on so the engine drowns out all other noise, lol( joke), 3 upgrade to a d3. ( hmm might have to take that insurance policy out on the wife, lol.) seriously though, does any one know how dificult rebuiling a tranfer case / diffs would be , e.g special tools needed e.t.c, i have rebuild a few ford toploaders , so not a complete gearbox noob, lol , but it has been a few years. cheers

 

I would just buy used ones, diffs are cheap and easy to replace, t-case not so much.
Start with the front diff, then if it continues do the rear, save the t-case for last.

 

Just to follow up,

I had the transfer case changed on Friday. As I suspected, the grease was thin to the point that the mechanics suspected it had motor oil in it. We changed it and I went driving for an hour or so.

It is obvious that the grease change made a difference in driving, but it was not the silver bullet with my noise. At this point I am running out of moving parts to change. My next option is to get the wheel bearings repacked. Does anyone have other suggestions?

Done so far:
Rear drive Shaft
New tires
Brakes/rotors all around
Relube front/rear diff and transfer case
New Alternator
New pulley/tensioner
New AC Compressor
New Water Pump.

There are no OBDII error codes. Noise gets louder as the vehicle moves faster. Putting the engine in neutral at speed the noise still exists. I plan on an alignment after Christmas.

 

I think if it were the wheel bearings they would have seized up by now.
Not to mention that when you replace the rotors you must repack the wheels bearings anyway.

 

Thanks. I guess I need to put it up on a rack and run it up to speed. Not sure if anyone cares, but I will keep updating this thread until I find the resolution.

 

yep the gear oil made a slight differance to my whine, but after 1000klm is still driving me nuts (might fill the tranfer case with bannana skins and sawdust, lol) i just fitted new wheel bearings all the way around, because i had bearing rumble at the rear, while it got rid of the rumble, and made the car feel much nicer on the road, it did nothing for the whining noise, (but i was,nt expecting it too). i was starting to think it was defently my front diff, but after mucking around the other day i noticed that when i,m at the right road speed and the whine is starting to get loud, if i click down a gear so the rpm rises and leave the throttle the same , doing the same speed,the whine jumps up a notch and gets higher pitched( like a high pitched whistle) which in my mind rules out the diffs because the whine get louder with increased rpm but the diffs are still spinning at the same speed, does that make sense to anyone?, but the whine is still there when you coast in netural, so i think that rules out the tranny as it whines in every gear including netural , so i,m only left with the transfer case, (which i,m considering rebuilding myself), does that sound like i,m on the right track ? any hints on the rebuild? thanks..............rick

 

i certainly care senator, lol , let us know how you go, cheers mate.

 

I have to agree that that test rules out the diffs, but I am not convinced it is the t-case yet.
I would think the t-case would not speed up with a gear change in the trans, the wheels are turning the same speed, the only difference would be the gear in the trans and the engine speed.
But the gear oil change in the t-case made a slight difference in the sound, so I am not 100% sure what the problem could be.
Have you changed the fluid in the trans yet?

 

yep, i had the trans flushed and serviced about a week ago, i was going to do it myself , but 17 12 hour shifts in a row got in the way of that , lol. the heavier gear oil made a considerable diffirance, the thing that makes me think it,s not the tranny is it does,nt matter what gear your in, if you get it up to speed it will whine, but i honestly know nothing about auto boxes or transfer cases for that matter, so your input is most welcome, for exsample if i was doing 50 kph and changed intro netruel the whine would stay the same, but if i changed down a gear the whine will increase with a higher pitch, a bit stumped to say the least. thanks for your help................rick

 

re; if i changed down a gear the whine will increase with a higher pitch,

and

does,nt matter what gear your in, if you get it up to speed it will whine,

So no whine while parked and revved to approximate rpm of road speed? That would eliminate many engine things (pulleys, etc.).

The down shift + increase in frequency seems to point toward tranny, even though recent fluid change. Did they change the filter assembly as well? A clogged filter can make the high pitched noise.