4 wheel drive clunking
 

i am having a wierd problem when i put i 2001 blazer into 4wheel auto i get clunking. also when i stop it sounds like it is stumpling on itself.

my friend was having the same issue when he was shifting his 99 ford explorer into 4 wheel drive. he took it to a mechanic and the mechanic told him nothing was wrong. i dunno if that helps any? also what do you mean it sounds like its stumbling on itself?

possibly u-joints

Clunking just going into 4wd or clunking the entire time that it is in 4wd? Does the 4wd work? In both 4lo and 4hi? If there is popping from the front end then that's cv shafts but a clunking from the t-case or front diff is a differn't story. Check the u-joints on the front shaft also.

You may just be hearing the engagement of the front axle.

like i hear it engage in all the drives except auto but when i am driven and i slow down or go faster mstly when i slow dow it feels as it may be slipping. but like if the transfer case is not locking copletely. like its grping somewhat but coming off. sorry i am tring to explain it the best i can. i am just lost with the auto 4x4 drive vehicles

You should not be feeling it when driving on normal road surfaces. If you are turning on high traction surfaces with it in 4HI or 4LO, then you will definitely feel it as the drivetrain binds and releases (tire skids).

When in Auto4wd, the front axle should engage when you hit the button, but the transfer case will put power to the front axle when it has determined that there is slip in the drivetrain.

would it have anything to do with the transfer case motor. i feel it more when i slow down to a complete stop.

Could you describe what you are feeling in a bit more detail?

Does it do this in 2HI non-auto?