Drive train noise....somewhere

[Jobi-Wan Kenobi]

So I have this odd noise that shows up when I'm driving with four wheel drive engaged. Really it shows up almost as soon as the vehicle starts moving. I had thought it was coming from my front axle assembly so I swapped in a replacement but there was no change. It's not tire related. It doesn't change with the type of road surface I'm on. Is it possible that one of the front hubs would be loaded in some weird way that would cause this? I have no hub noise otherwise when I'm in two wheel drive.

I had gotten to wondering about the transfer case here too. After I started looking into transfer case issues I found the issue for the worn pin hole. As of right now though mine is dry and not leaking. Would there be any other symptoms that can be observed before a leak would start?

 

[justirv]

So I have this odd noise that shows up when I'm driving with four wheel drive engaged. Really it shows up almost as soon as the vehicle starts moving. I had thought it was coming from my front axle assembly so I swapped in a replacement but there was no change. It's not tire related. It doesn't change with the type of road surface I'm on. Is it possible that one of the front hubs would be loaded in some weird way that would cause this? I have no hub noise otherwise when I'm in two wheel drive.

I had gotten to wondering about the transfer case here too. After I started looking into transfer case issues I found the issue for the worn pin hole. As of right now though mine is dry and not leaking. Would there be any other symptoms that can be observed before a leak would start?

I'm not aware of any symptom of case wear outside of a leak. How is your transfer case fluid, changed recently? Look good? Correct fluid? There is a "case saver" which isn't hard to install if you pull the transfer case and split it. There's also a hyvo chain and a clutch pack in there as well, with bushings, bearings, and seals. A Kent Moore J-44295 Clutch Pack Shimming Tool (or similar) is "required" to set the clutch pack (if replaced), some have gone without, and others have had a capable trans shop either set the clearance or rebuilt the transfer case. It's not too difficult to pull it and crack it to take a look. If I recall its takes sealant to close it up; I'd look at a case saver and gasket/seal set minimum if going that far. I'm not sure hubs would make noise only in 4wd. How are the u-joints on the forward drive shaft?

 

[Jobi-Wan Kenobi]

@justirv I'm not sure on the state of the fluid and do want to change it.

I have found the case saver and at a minimum do want to put that in. I've been thinking too about even picking a good used case to do a rebuild on and then just swapping that in, though not really that's necessary.

I don't really think its the wheel hubs causing it either. The tone of the noise doesn't seem to change when I go around a corner. I had thought the noise was a gear noise which leda me to changing the front axle assembly. The u-joints on the front shaft are both original but are still tight.