4wd noise, is this normal?

I bought a 1977 jeep cj5 with a 258 and a 3-speed transmission. everything was very original with this vehicle. It looked like it had almost no work done in about 20 years. It had original AMC plug wires still on it. I gave it a tune up and have also done some other minor repairs. It has responded very well to the work I have done to it. runs great. We got some snow the other day, and I engaged the four wheel drive, which I admit I don't do often enough. When I engage the four wheel drive there is a low rubbing/grinding sound coming from the transfer case, it doesn't sound too serious, but my experience is that noise and transmissions are not good. the 4x4 works just fine but there is the forementioned sound. is this normal on a jeep which is thirty years old and has probably never had the tranny fluid changed? Is the tranny fluid seperate from the transfer case oil? what should I do?
Any response would be appreciated.

 

- it could be a collapsed mount or missing mounting bolts
- it could b emissing or loose torque mount
- it could be low/no oil in the transfer case
- it could be dry/worn out front driveshaft u-joints
- it could be a bad ujoint on the front shaft
- it could be bent driveshaft hitting something
- it could be shift lever hitting body/floorpan
- if in low range, growling from the unit might be conisdered normal sounding
maybe a looksee underneath would reveal something

 

When in 4wheel there are several bearings turning that don't in 2wheel. You might have a bad bearing in the transfer case. Are you hearing the noise in low range or high? Like Jim mentioned, a growl or whine is normal in 4 low. Do you have locking hubs? If so you could lock them in and drive in 2 wheel. That would turn the front drive shaft and axles. Might..help determine from where the noise originates.

 

john thanks for replying to my question. I am hearing the noise in 4 high. i do have locking hubs and i did drive in 2 with the hubs locked today, and the noise was barely there. in fact i am not sure that i heard it, might have been my imagination. it is sort of a whining sound now that you mention it. also when i am downshifting, when i let the clutch out, the noise goes away for a second and then slowly starts to whine.

 

I get that in second gear 2H (not to mention all my low gears). Hasn't been a real problem yet, but I found sometimes if I put the clutch in and push harder on the shifter (towards 2nd gear) , it will go away, sometimes.

 

i am going to change the oil in the transfer case and differentials first, to try and rule out some of the possibilities.