Hi. I lifted my 2014 JKUR (3.5” MetalCloak TDR) a few weeks ago and have noticed a slowly worsening hum that I can feel in te floor boards and gas pedal. When I let up on the gas it’s becomes less noticeable. The only other thing I’ve noticed is a bit of an audible rattle and times.

When cruising at slow speeds I can’t really feel it. I have rolled around on a creeper under the Jeep trying to reproduce the sound with taps from a mallet and nothing. I’m suspecting it’s maybe in the rear diff? Wondering if the new driveline angle because of the lift was enough to push an already worn bearing/part over the edge.

Also. I’m running 35” KM3’s and 2” spacers. Jeep has almost 60k miles and I’ve had zero issues like this in the past. Can someone please point me in the right direction?

thank you for any input at all.

 

West have you done about your driveshafts? They can make a little hum and vibration with time.

 

Agree check ds and retorque everything

 

Hi thanks. Drive shafts are stock. I’ve checked to make sure everything tight as far as lift components. There is very little play in the driveline when I turn it by hand. Nothing seems out of the ordinary. Dumb question but isn’t the front drive shaft normally the first to go after a lift? I suppose that couldn’t be turning when I’m in 2wd on the pavement. At a loss.

might pull the diff cover off and take a peek.

 

You've got a 3.5" lift with stock driveshafts, that could easily be a part of it. Did you actually net 3.5" and what did the kit do with your front control arms? Even doing something like brackets for the front will still put a bit of stress on that shaft at the new operating angle. Since you've got the unlimited and your vibe is coming from the front, you've got nothing to lose by pulling that front shaft and driving around. You're correct to a degree on the 2wd thing but with our live axles, that front shaft spins all the time, regardless of tcase position, that's what makes it able to go into 4wd "on the fly, up to 55mph".

 

Okay makes sense. I actually think the vibration is coming from the rear though. Again, I feel it mostly on acceleration.

 

Did you ever figure this out?

I have what feels like the same vibration you describe. I feel it in the gas pedal under load at low RPMs. No noises or clunks though. Thanks.

 

The Barings/Knuckles within your drive shaft are worn. Possible a bad shaft angle due to a bad caster angle.

 

Thanks - Considered that. I took out the rear shaft and drove it around then pulled the front shaft and drove it around and no change. In gear with my foot on the brake I can't reproduce it, smooth as silk. Truck has to be moving to feel it.
You can change the severity of it by playing with the gas pedal. Low RPMs under load is the worst. I'm starting to think its a transfer case bearing.

 

I personally can not verify if it's your transfer case. But how long ago was the case fluid changed? and was it changed with the correct fluid.