Used 4x4 today for first time, slight noise up front...

I have a 1995 Tahoe 4x4 with the floor shifter for the 4wd. I just got home during a freezing rain storm and used 4x4 for the first time today at road speeds. When I had 4x4 on, I could hear a hum up front that it doesn't normally make. I took it out of 4x4 and it went away, and came back when I went back in. Its very slight and if the radio was up it could be missed.

Is that a normal thing with the chevy system or could I have a problem with the diff? I am going to get under there and check the fluid level in the next few days and see whats going on there.

Just doesn't seem right, the dodge I replaced with this was silent when the 4x4 was on, so I want to look into it.

i cant help you with your problem but i am going to help you avoid a serous one:thumbsup:

i think i red that your not supposed to use 4wd on pavement, even wet , because your still gripping well, you can use 4wd on loose pavements becasue its less stress on the diffs, when you turn in 4wd you cant turn to the left and the right all the way, thats why hummers full time 4wd is 40/60, in 50/50 the gears could get so meshed so hard it CANT ever come out of 4wd. heres an article.

http://www.4x4abc.com/4WD101/def_turnpart.html

it kind of depends on how fast you drive the truck. 4x4 is not designed to work at high speeds on any vehicle. my Tahoe makes the same noise but im not to worried about it because 4x4 is not designed to work all the time. just when you need it to get unstuck or what ever the problem may be. i dont really think i would worry about it untill it starts to get louder or if you start to feel a vibration in you feet or the steering wheel.

yea even if u use 4-hi it is not designed to go above 20mph or so.