loud clicking from front wheels in 4x4
 

I was testing out the 4x4 in my new jeep the other day and while in part time when you turn the wheel there is a clicking coming from the front wheels. it doesn't do it in 2x4. any thoughts? its an 89 xj 4.0

My buddy has some bad ujoints in his front end. And they kinda click when he is in four. Check that out.

If it's definitely coming from the area of the front wheels it is most likely bad steering knuckle U-joints.

it doesn't do it at any other time though. only in 4x4 and when you turn the wheel. wouldn't a u joint be doing it all the time or even in 2h?

Your noise is more than likely related to the vacuum disconnect ont he RH side of the front axle. When you engage 4wd a shifter fork is supposed to move a part that links both sides of the axle. The diaphragm may be bad, vacuum line leaking or missing, broken shifter fork, etc. Pull the cover off the vacuum motor and have a peek.

It's really easy to check your steering knuckle U-joints. Try to wiggle the axle shaft on the inner side of the U-joint. If it moves side to side at all, that is the source of your noise. If you can move them the clicking noise in 4x4 would be the joint moving under torque and hitting the sides of the needle bearing caps. if they are completely tight then look elsewhere for your noise.

thanks for the advice, its most likely the vacuum lines, there was a rubber piece that the lines connect to and that was loose and leaking.