when i put my truck into four wheel drive when i crank the wheel it make a thunmping noise like something is rubbing. My dad said he has had this hadden to him before on his chevy blazer but he cant remember what it was. can anybody tell me what it is?

 

put the truck on jack stands and run it in 4wd to see whats going on could be a CV going bad

 

You're not doing this on dry ground are you? If so, that's the driveline binding, bad thing for it.
If not I would agree with the CV thought.

 

it does it on dry ground

 

That's binding, the driveline is binding b/c your front and rear axles turn at diff rates. You will break something if you keep doing that...in mud/slippery surfaces, the difference is made up by the front and rear axles slipping.

 

so if i only use my 4 wheel drive in mud and snow this shouldnt be a problem??

 

If you have the same size tires (granted they're at the same pressures) and same front and rear axle gear ratios, you "should" be able to use 4wd in a straight line and not have a problem.

 

correct. snowy/ icey roads, mud, sand dirt ect is where you use your 4x4, never on dry pavement

 

unless you want alot of broken parts then dry is fine!

 

the only reason i had it on on dry pavement is because i was wheeling it this weekend and i wanted to make sure everything still worked right. I'm kinda new to 4x4 so when i heard that noise when i tried to turn it kinda freaked me out.

 

Yeah, a stragiht line is no problem, but when you turn in 4wd the front and rear want to turn different sized circles, so something has to give. In mud/snow that's fine, the tires can slip and slide....dry ground however, something will stress, bind,a nd eventually break. NEVER turn (especially hard) when in 4wd and on a grippy surface.

 

just one more question. Does this happen in all trucks or is there something i did to make my truck this way?

 

All vehicles with 4wd capability, not AWD unless you can lock it into 4WD, will bind up on a dry surface when locked into 4WD if your are turning or if you have different sized tires front and rear.

 

It's all trucks. Mine does it as well.

 

well i took my truck wheeling and it makes this noise even when in the mud.

 

my wheel bearing just went out could that be what was causing this noise?