vintagephilg

I just bought a beautiful 1999 Jeep Cherokee sport from the orig owner, in exellent condition, but it makes a "humming noise" from somewhere up front (sounds like poss a wheel bearing??) seems loudest betwee 40-50 mph. And seems to decrease or pretty much go away at highway speeds....does anyone know what it might be?? how can I fix it??

It was a fantastic deal, Black Cherokee Sport from the orig owner (I even have the orig window sticker!) with a a new factory 4.0 engine that only has 70K on it!! I even have all the maintenace records!! Its in fantastic condition, and even has a mint grey leather interior the owner has installed.....I bought for $2,000! I love it! Just need help with the huming noise/issue.....


Phil

storm101

I had a nuts noise too really kicking in after about 30 on my 99 when i bought it also, that was a wheel bearing, how would you describe the noise....more of a growl/howling noise? thats about the only way i can describe what i had, and at 50-55 it was quite overwhelming....


I would check the wheel bearing/hub assemblies, jack the front end up and try to wobble the tires in and out with hands on 12 & 6 checking for play, if theres play chances are the bearing is bad, another way to check, which is how i found mine, is take the front tires off, remove brake pads, caliper, and rotor, and spin the hubs by hand and just listen for a grinding noise, if one does it and the other doesnt, its a good bet to say the noisy one is the issue....or if theyre both noisy maybe both


If you happen to figure on a wheel bearing being bad, and are going to do it yourself, make sure to check what type of rotors you have, cast or composite, because they require different hub assemblies (the whole assembly needs to be replaced if the bearing is bad due to it being a sealed bearing), easy way to tell the difference is to measure the center of the raised part of the hub if its about 12mm high its the composite type, if its 19mm its the cast, heres a link to somemore info on how to change them and check the difference between the two on the bottom. http://www.go.jeep-xj.info/HowtoHubReplacement.htm

I highly suggest making sure you know what assembly is needed its a pain to get it apart and figure out you thought you had one and actually indeed have the other...........yes i did that lol. Just measure it out and youll be good

Oh and if you happen to need 3 new hub bolts, and its the cast type.............12mx90x1.75 bolts will replace the old ones, i got some at napa.....took a while to find so im sharing in case you happen to have the same thing happen to you that i did to me a few days ago, anyways sounds like a great jeep, the 99s have some odd things go haywire but usually nothing major, or at least in my case, great year of a great vehicle

Oh and heres a list of tools you will need

Jack stands
13 mm 12 point socket 3/8” drive (It’s very important that this socket is 12 point. You can substitute a 1/2" 12 point.)
19mm socket 3/8” Drive
36mm 6 point 1/2" Drive
Breaker Bar or Air Powered Impact Wrench
Needle Nose Pliers
Lug Wrench
Foot Pound Torque Wrench
Jack
Wire Tie or 12” piece of wire
New cotter pins 2" x 3/16"


The 1/2in 12pt seemed to fit better for me

jd_skillz

My xj is doing the same thing. its ok when i first start driving it for the first couple blocks then the humming starts. It also feels like my jeep is being held back. Between every gear change or when i let go of the accelerator the jeep falls back or reduces sleep. could this be the front bearings or front diff?