Hello all, I as of last started experiencing a humming/vibration at 35+ mph, it sounds like it's coming from under the center console area, so I get under the Jeep an start grabbing ujoints trying to find play which I can find none whatsoever I also jacked up the front an started shaking tires trying to find play in the bearings, which I found none (even took off the brakes an turned it by hand in a quiet environment to see if I could hear anything, but still nothing) I also went to my tire guy, an he looked at my tires an said they were fine an also that most tire related vibrations don't occur at that low of a speed, so I'm at a loss here, BUT I do know that the joint in my track bar has been popping for sometime (never affected handling at all) now could this be causing my vibrations or should I be looking at something else? Thanks

 

Im having the same issue with my 99. Everything checks out fine. Hope someone knows on here.

 

How about differential and transfer case fluid levels? Spline joint lube or wear?

 

I checked the rear an it was fine, just changed the transfer case fluid this winter, and haven't looked at the front diff yet as I saw no signs of leakage, and the spline is the part of the driveshaft with the zerk, correct? If so I've greased that as well. It should also be noted that it start acting up last week but mysteriously disappeared only to reappear 3 days later

 

OK. How about transmission and engine mounts?

 

How old are the front unit bearings?

 

I have looked at the motor mounts an they both look good, haven't checked out the tranny mounts yet, (not real sure where their located to tell ya the truth, an I just had both my front axle ujoints replaced about 4 months ago an the mechanic didn't mention anything about my hubs being bad (though he did mention the track bar, which I already knew about)

 

Look at the back of the hub bearings where the shaft goes through. If you see a lot of oil that looks like it was slung outward from the unit bearing, you need bearings.

 

Well guys I looked at the back of the hubs an they were both dry, I had also checked the tranny mounts an it was good as well, HOWEVER I jacked the rear of the vehicle up and had the girlfriend put the vehicle in drive an run the engine to 35 mph an I could here a grinding/vibration coming from the drivers side rear, now we shut off the vehicle and I grab the tire at 12 an 6 o'clock an push an pull, sure enough I get what sounds like a loosely tighted rim moving on the studs, (it's not) I also get the same effect on the passenger side rear as well, now I would think it would be a bit odd for both to go at once, so is this normal or what should I be looking at next? Thanks

 

It should also be noted that this play cannot be visably seen only felt, I would imagine it's only a few millimeters

 

The play is normal but the noise and vibration aren't. If you believe it's coming from the rear differential pull the cover. Look for metal slivers,particles,etc in the oil and in the housing. Could be a bearing problem.