I'm about to install my lift and tires on my cherokee and all of a sudden I'm having a loud sort of humming noise coming from directly underneath me it seems whenever I'm at half throttle and hit about 55-65mph and then again at about 75 on. The noise stops though when I let off the accelerator. Want and need to get that fixed before I start the lift install. What the hell is that?!

 

By the way, I have about 118,00 on her now

 

could possibly be as simple as an exhaust leak. you might want to check the fluid level in your transmission and possibly the transfer case too.

 

You may need to check the U-Joints, there should be no play in the U-Joints at all, and it can be a pain to replace them.. If you're going to do a lift you should replace all the U-Joints anyway because it changes the driveshaft angle... Could also be a wheel bearing or hub. Grab the wheel and check for movement while the vehicle is in the air (jack it up or something).

 

I do have an exhaust leak but all the way past the muffler. I'm cutting it off as well, but the noise is a different story I believe. I have a different noise because of the leak.

 

Oh and yea, the tranny fluid was a little low...filler her up, but there is also a little oil coming from where the driveshaft meets the transmission and also there is a little oil residue on the bottom side of the transfer case.