[Andytron]

At first I ignored it since I had no time and no place to work on, it but now that I've graduated college I'm gonna fix it. It's a moderate noise that sounds like well... zzzzzzzzzzz more or less coming from the drivers side front. I thought it might be the tire so I swapped it to the other side. No improvement. The noise is most noticeable between 25-35mph while coasting. The noise has been heard all the way down to 15 mph. Sometimes it's there other times it's not. Braking slighly modifys the sound or even makes it appear or dissapear. I'm thinking slightly draging d/s brake caliper, bad hub assy, bad axle bearing or front driveshaft u-joint(s). This has become quite annoying and I got a big road trip coming up so I'd like to fix it asap. I may pull the calipers off tomorrow and look at the rotors real good as well as swaping out the pads. Let's see if we can nail this one so I don't have to take it to a real mechanic.

 

[109]

Andy, I hope it isn't anything that's real serious. It could even be a loose hubcap. Those little screws can strip out fairly easily. Good Luck!!/wwwthreads_images/icons/smile.gif

 

[Andytron]

I hope it's nothing serious too believe me. As for the little center caps, they are tight.

 

[Guest]

there's not too much there. i would first check hub assembly it contains the only bearing there.you can remove the caliper by takeing the two 1/2in bolts securing it to the knuckle. at this time check for unusual wear on the pads or rotor.then simply pull off the rotor and grab the hub firmly and try to wiggle form side to side.if no movement then with the other front tire off the ground rotate the hub to feel for any ruffness in the bearing .this should tell you imidiately if the problem is in the brakes or hub,at the same time inspect the u-joint for looseness or stiffness(stiffness is sometimes hard to detect without removeing the axleshaft) this should get you started. if the problem is not imediatly evedent then the hub assembly may need to be removed to check the u-joint.these are really the only three things in that area that could produce such a noise. hope this helps!!!!

 

[Chris_MJ]

Repack your wheel bearing while you're in there. Just dab a thick pad o' grease on the palm of your hand and whack the edge of the bearing against it to work it in good.

Ah heck, you knew that. I'd have to hear the noise, but I do know that bearings will make howls at high speeds, grunts at real low speeds, and whirs at midspeed.

'88 MJ SporTruck
365K on 2.5L (Energizer Bunny Package)

 

[Guest]

Sounds to me like you may be dealing with a front hub/axle bearing going bad. Does it make a different noise when you are turning right or left like on a freeway off ramp? Since these are sealed units (at least in my comanche) they can be replaced as a set. The Timkin set I purchased was a complete bearing/wheel hub unit so assembly or grease packing was not required.(Some are available as 2 seperate assemblies that you have to press together before installation) Pull the wheel, remove the nut holding the drive shaft, lube up with penetrating oil real good, remove the star bolts from the spindle and remove the bad bearing assembly from the spindle and shaft. Reassemble in reverse order. Your done. Just be sure you are replacing the correct one. I thought my right side one was going, and it turned out to be the left side one that was bad. Its a whole lot cheaper to replace one bad bearing set, than one good and bad one. My old right side is still running 2 years later with no problems. The mechanics and service quys told my that they generally wore out at about the same time, but I only needed to replace one side on mine.

 

[Andytron]

The noise dosen't change when turning. I was kinda suspecting the hub but while driving tonite, the noise didn't start till after I had used the brakes enough to heat them up a bit. So with that idea in mind I started thinking of thermal expansion. I figure something brake related is heating up and expanding enough to barely make contact. So as a result tomorrow if it dosen't rain again I'm pullin the wheels again and lookin real close at the calipers, pads, rotors and especialy the caliper bracket. I figgure that if the caliper can't slide real well it may be hanging up. And since I have an extra set of rotors and pads I may throw em on just to see what happens. Keep them ideas coming just in case.

 

[Guest]

CHECK THE THIN METAL GUARD BEHIND THE ROTOR IT MAY BE BENT AND RUBING SLIGHTLY ON THE ROTOR .THAT HAPPENED TO A FRIEND OF MINE AND THREW HIM FOR A LOOP!

 

[Andytron]

Well I think I nailed it. Between all the gunk and rust on the caliper brackets and the cracked pad plus the sticky caliper guide bushing I was cruising for a world of hurt. But anyway on with the story. So I pulled the wheels off again in the 90 degree heat(fun fun)and started looking at things real close. I noticed the caliper brackets were real gunked up so I pulled the calipers off to clean them. So after a good wire brushing and a slathering of anti sieze I think to my self I'm in buisness. But then I thought I'll take a little closer look. My pads didn't look to bad at a glance but under scrutiny they were lookin shabby. The inside pad on the passenger side was cracking in 3-4 places. Luckaly I had a set of Wagners in stock in the garage that were meant for my dads truck(same P/N ha ha). Slaped em in and threw the calipers back on. Put the wheels on and drove her for a while tonite and not a peep. Stops better too. Now my next question is who has had metal worn away from the caliper bracket because the shoes rode in the same spot too long?

 

[Chris_MJ]

Me me me !!!

I have. Not on the Jeep though. It was my first car -- a Honda Prelude. Most brakepads have a little leader of metal sticking out so that they squeal a little (like for another 1000 miles or so) before they get so worn you ride mostly on metal. These didn't. It was so fun getting crappy braking distance accompanied by a spinetingling shriek of metal rubbing up against metal at high speeds.

Glad your problem is solved -- and just in time, too! There's a great story about the clutchplate with some serious rivet wear that I found during the rebuild of my 2.5. It was like everything just needed to be replaced at once. it was very handy and I have to thank the MJ for being so nice to put everything off until one point. So much easier to do clutchwork with engine on the cherry-picker.

'88 MJ SporTruck
365K on 2.5L (Energizer Bunny Package)

 

[Andytron]

Chris, you wore the rotors out or the caliper brackets? My rotors were fine whereas my passenger side caliper bracket has a pair of dimples in it from a set of shoes riding on the bracket in the same spot for too long. Just trying to clarify.

 

[Chris_MJ]

Dang, I read your last post too fast. I was talking about the shoes. So I guess I'm not as cool on the "running-at-the-limit-of-your-braking-problems" scale.

'88 MJ SporTruck
365K on 2.5L (Energizer Bunny Package)