Transfer case or Front End whine/growl.

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Saucy_Walnuts

Saucy_Walnuts

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I'm not saying this is the problem, but the specified fluid for that transfer case is AutoTrak II, which is blue in color. How dark is the T/C fluid, and does it look more like transmission fluid (reddish) or....

T/C drain and fill takes just under 2 qts.
It's a dark blackish Grey. And I was going to change it out anyway because I have no idea when the last time it was serviced.
 

OR VietVet

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I did do that last night after logging off. I jacked it up and spun the bearings and checked for play. None was to be found
It's a dark blackish Grey. And I was going to change it out anyway because I have no idea when the last time it was serviced.
This is why you need to address the "known" and do the "blue fluid" change and deal with a known problem.

The noise can travel inside the cab and could be from the rear. If you have no idea how old the diffs and transfer case fluids are, change them.

Also, when I talked about a 2wd drive in a straight line at 25-40 mph and turn left and right to listen for increased noises, I mean slight turns. Like a quick dodge of a pothole in the road. Not a 90* turn but a slight steering wheel move from 10 to 2 o'clock. As you turn left you will throw the front weight to the right front and that can make the right front bearing make more noise. Same aspect as you would turn right and load the left front. You can still have straight down the road noise from front bearings but the right/left slight turn can help pinpoint the problem side.

If noise is coming from rear, get rear tires off ground and in neutral, check for in and out play, up and down play and noise when roll them. Look for axle fluid leaks, too.
 

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How about the front differential? My truck is AWD, but I had a growl in the front end, and when the mechanic put it on the lift with a person inside operating the shifter and throttle, the mechanic used his stethoscope to pinpoint the source of the issue -> front differential was shot.
 

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Saucy_Walnuts

Saucy_Walnuts

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This is why you need to address the "known" and do the "blue fluid" change and deal with a known problem.

The noise can travel inside the cab and could be from the rear. If you have no idea how old the diffs and transfer case fluids are, change them.

Also, when I talked about a 2wd drive in a straight line at 25-40 mph and turn left and right to listen for increased noises, I mean slight turns. Like a quick dodge of a pothole in the road. Not a 90* turn but a slight steering wheel move from 10 to 2 o'clock. As you turn left you will throw the front weight to the right front and that can make the right front bearing make more noise. Same aspect as you would turn right and load the left front. You can still have straight down the road noise from front bearings but the right/left slight turn can help pinpoint the problem side.

If noise is coming from rear, get rear tires off ground and in neutral, check for in and out play, up and down play and noise when roll them. Look for axle fluid leaks, too.
I will try that. I will be servicing front and rear diffs. Along with the Tcase this weekend. When I looked I did not notice any wetness/dampness on front or rear diffs. There was a slight wetness on the Tcase but it was full of fluid. I will check for play in the rear end when I service them.
 
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Saucy_Walnuts

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How about the front differential? My truck is AWD, but I had a growl in the front end, and when the mechanic put it on the lift with a person inside operating the shifter and throttle, the mechanic used his stethoscope to pinpoint the source of the issue -> front differential was shot.
I will have to see about that and may need to do that. I believe I have a mechanics stethoscope somewhere
 
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Saucy_Walnuts

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On my ‘99 my t case started making noise and turned out to be the pump shaft rubbing on the tcase housing. They make parts to prevent the pump shaft from rubbing through the soft magnesium case like.. https://www.amazon.com/TIKSCIENCE-Transfer-BRNY4080-78889-482460/dp/B095LQQCRV or alternatively some rebuilders use a harder aluminum case instead.
I did read about that being a issue. I will most definitely look into it. I might as well rebuild it while I've got it apart
 
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Saucy_Walnuts

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Well I think I found the noise. I probably need to rebuild the front diff or find a good used one.
 

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OR VietVet

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That is nasty looking and could be close to normal if it was the first fluid change but if is still rounding off sharp edges this many miles down the road and fluid is original, I would clean it out completely and add new fluid and drive it to see what happens and if does quiet down, then change fluid again at 5k to 10k miles.

Plus, make sure you do the rear diff and the transfer case.
 

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