So driving home today my jeep starting making a noise like a helicopter . Like something was on the underside just wapping with every rotation . Noise gets lounder if I brake hard . Is completely gone stopped at idle or moving under a decent load . I hit a box on the way home (it was unavoidable ) but I checked underneath and there's nothing visible down there . Putting neutral and even shutting off the jeep while moving has no effect on the noise. any help is appreciated

 

A full box or an empty box?


Sounds like you have knocked something loose and it's flapping in the wind.


Go around your rig again and tug on everything to see if something is loose - trim, plastic covers, wheel wells, heat shields etc.


if the box was full - check rock guards (if you have them) and braces for damage


s

 

Get it up in the air and get underneath .....

Check in and around everything that rotates starting at the U-Joints out of the transfer case and work you way out from there.

Check behind each wheel.

 

Re-reading it and this popped out.

Not sure where this leads to but it might set off a light in someones head.

Noise while moving ..... even with engine shut down and truck in neutral.

Noise goes away while moving under decent load.

Something has come loose, and is beating against the vehicle somewhere.

Under load there may be enough flex as to widen the gap between the loose item and what it is beating against so the noise stops.


scottfisher

 

Did a "friend" put a zip tie on your drive shaft for April fools day?

 

 

So got under it today and there was large rubber line runs down the driver side of the body to a box in the back . Whatever it is had popped out of its holder and was rubbing the front driveshaft . Jeep is fixed and for once cost me free.99 appreciate the answers guys !