1994 Ford Explorer Q&A
1994 Ford Explorer Question: Popping or ratcheting in front end?
What is the condition of the front axle and axle u-joints? If an axle u-joint is seizing up, it could make some noise, and probably vibration. You're sure it's not a rear locker making noise? If you can, have a shop look at it before you buy it. This could be something easy or it may be something more costly. wish i had more for you, hope this helps - Andy Y
it could be the bearings or the bushings... - stougiegal