PresidentBDETH

I just bought my first XJ a couple of weeks ago and I'm experiencing a loud low rumble at or above 65 MPH. It's not really a gradual increase, it just pretty much hits any time I'm above 60-65 MPH regardless of whether I'm on the throttle or not. It sounds like it's coming from the rear middle. Could be the transfer case, differential or wheel bearings. Wondering if anyone has dealt with this specific problem. Any advice is helpful. Thanks!

RudeXJ

What kind of tires you running?
I had something similar coming from the front, was my front drive shaft slightly out of balance.
Have you checked your ujoints?

PresidentBDETH

Thanks, RudeXJ. I don't have much mechanical experience but I imagine that's going to change as an XJ owner. U-joints, differential, transfer case and wheel bearings are on my list to check.

I'm running 29" BFG A/T Baja tires but the noise is definitely distinct from the tire noise. The low rumble is only above 60-65 MPH while the tire noise is pretty much constant and higher pitched.

RudeXJ

Its really difficult to diagnose a noise through a description and in the end of the day we can only make suggestions and you’ll have to check it.

Id suggest trying to film a video and upload it to YouTube and post the link on here, that’s what I’ve done before and found it quite useful...I’ve had my fair share of “strange noise” threads

Youre on the the right track so far - do you feel any vibration? When I had bad u joint it definitely had a vibration. diff and bearings generally make a very destinct noise, either a howl or a whine.

Another thing to check is your transmission mount. It sits next to the exhaust and often goes bad and causes vibration.

PresidentBDETH

I don't feel any vibration. It almost sounds like a constant exhaust note, but only at high speeds, regardless of throttle. And I've never heard the noise at low speeds, even at full throttle. I'll try to capture the sound in a video.