front end noise

Hello, my names Austin, I'm new to this forum, but ive had a 99 jeep xj for the last 8 years. I'm no expert but I do know the essentials on the 2wd xj.


Completely stock 99 jeep xj
282k miles
New LCA and bushings, UCA and busings, track bar, all tie rod ends, passenger side ball joints, steering stabilizer, sway bar bushings and end links, rear sway bar bushings and end links, 4 new tires and alignment all within the last 2 weeks.



Notice this problem started before I did a complete front end rebuild.


About 2 months ago I started hearing what sounded like a bad wheel bearing, ive replaced both front bearings twice throughout its life so I thought I knew what it was.



It starts around 15mph and you can hear it up until about 50 when the exhaust drone from the flowmaster 40 takes over...it doesn't change with brake pressure.


Well today I took both front wheels, calipers and rotors off and both wheel hubs spin freely with no grinding/rough noise to them. Completely confused, I greased the pads and calipers and reinstalled, put the wheel back on and spun both sides again. No noises. Lifted the rear because I was sure it was wheel related, no noise out of either rear wheel.


So calipers should be crossed out because it doesn't change with braking, wheel bearings seem fine, where does this leave me? Driveshaft? Ujoints maybe?

I'm not sure if there's an "edit" button but I forgot to add, its 2wd. So no front driveshaft or differential.
Plus a little more info on the problem, correlates with wheel speed, rough/grinding noise stays while in neutral coasting, only not new components are shocks (about 2 years old) and driver ball joints about 3 years old but don't have play, coils and leaf springs are original

Are the hub bearing perfectly tight, zero play?
Any amount of noticeable play is unacceptable and will cause noise and can lead to death wobble.
Are you sure the noise is from the front end?

There isn't any play in any direction, and I'm almost certain its from the front passenger wheel area. I drove it today and still swear it sounds exactly like a wheel bearing.

After rebuolding the front end I figured it would have no wobble at speeds, but around 65ish it has a small wobble then goes away around 70. I also read recently wheel bearings can show no sign of being bad without the weight of the vehicle on them... But ive never experienced that lol, all mine that went bad sounded like crap with the tire off

mbeas96 said:

There isn't any play in any direction, and I'm almost certain its from the front passenger wheel area. I drove it today and still swear it sounds exactly like a wheel bearing.

After rebuolding the front end I figured it would have no wobble at speeds, but around 65ish it has a small wobble then goes away around 70. I also read recently wheel bearings can show no sign of being bad without the weight of the vehicle on them... But ive never experienced that lol, all mine that went bad sounded like crap with the tire off

Click to expand...

Any change if you swerve side-side? Often the outside bearing will get louder in a turn as it takes more weight. No pebbles stuck behind the disc brake shield and it's not rubbing the rotor? I've had those sound an awful lot like a bad bearing. Any noise with the back jacked up in the air?

Ill have to listen while turning tomorrow, I didn't check for anything behind the brake shield but all the wheels turned freely with no noise when in the air..

Nothing bad sounding from the rear, jacked it up and spun each wheel, sounded smooth.

ll have a shake at the driveshaft tomorrow to try and see if theres play in the u joints also

Location of noises can be hard to hear. Be sure its the front end making the noise. Sometimes its helpful to have someone else drive the vehicle and sit in the back seat or the cargo area. Or just put your seat all the way back so you can lean back and listen. "Makes noise at all speeds over 15MPH" sounds a lot like rear differential bearings to me. That's inside the differential. If you were able to run it on a lift or jack stands (be very careful - one fallen jack stand can ruin you and your garage) - you would be able to put an ear to it and confirm.

One trick I've used to localize strange sounds is to drive next to a wall. I seem to have better luck listening on the passengers side with my whole head out the window facing the wall.

Those sounds can fool you. I've been certain it was one area many times and had the problem be somewhere else entirely.

A bunch of good suggestions here for listening to noises. Ill second the motion for jacking up the rear of the vehicle to listen for differential noises. Use a jackstand on each side for this, and chock the front wheels. Just put it in drive and let it idle as the rear axle is spinning. i found grinding in an axle once using this method. Be Safe!
If you hear the grinding/humming noise and its changes its tone slightly on a turn, that would be the front hub bearings. It takes very little play in these to have a noticeable effect on the front end. They are simple to change and relatively inexpensive.

There aren't too many things it can be on a rear wheel drive--

Noise is related to wheel speed not engine RPM
doesn't change with application of brakes
doesn't matter if in neutral, coasting or engine chugging under load

One last thing I would do is rotate tires front to rear just to rule out bad tire/rim -- see if noise moves to the rear -- otherwise...

It's wheel bearings -- change them