I have a 2001 Jeep Cherokee Sport 4.0 liter 4X4 with 170K miles. In the past there has been a knock sound as I would back out like possibly the tie rod or cv joint or universal was having issues. Did not always happen. This weekend the sound was continual. Looking under the engine at the left (driver's side tire, I see a black tube with a metal piece laying on the differential joint which was I think what was making the noise as when it would turn it would throw this up into the bottom of car. The black tube has a cloth outside like some sort of heat shielding. It appears it goes to the front axel. Does anyone know what this is and what needs to be done. It drives ok.

 

Sounds like a breather tube. Does it look something like this?


Just ziptie up and out of the way. Doesnt need to be tight, just out of the way.

 

Yes but it had a solid metal part in the end and was partially covered by a fabric protector. Where would the opposite end of the breather tube be located

 

Trace the line. Could be for the axle, could be for the transmission, could be for the transfer case. I believe all of mine have a plastic cap. Dont recall a metal one. Or being covered in fabric. Mine is a 97.

 

Sounds like the fabric may be a PO "aftermarket solution". Is the metal thing possibly a mounting bracket (either OEM or another hack..)?

edit - sorry,... I mean "aftermarket solution"

 

For the breather line for the front diff. Isn't there a hole in the diff that has a piece of metal that you can remove? The rest of the breather line rubber hose part connected to that running up to the firewall with the little white top hat at breather at the end. Sound like he just needs to jam that metal tube back in the diff. If this is the case I would check the line to make sure that the hose did not get chewed up while flapping around under there.

 

Stock place for that tube is next to the brake booster under the hood I'm pretty sure.

 

Okay. my 2000 WJ has the same breather hose with the same problem. It fits into a hole at the top of the differential case on the rear side towards the wheel and the other end has a plastic fitting with a cap and clips onto the front shock stud. My differential end keeps getting pulled out by snow underneath and I have to keep sticking it back in. I'm tempted to thread the hole for a brass pipe fitting.