I was almost home tonight when I noticed a knock or thumping noise coming from what seems to be the left front wheel. It seems to be consistent with a spot on the tire, meaning it seems to happen once every rotation. I drove it slowly through the neighborhood and you can feel it when it thumps in the drivers floorboard. When braking enough to engage the brakes well it goes away. I pressed the brakes some and gassed it and did not feel it.

I was not able to pull the wheel and look at anything tonight. Will do that tomorrow. I was thinking maybe the caliper was loose, but was not able to budge through the rims.

It is a 98 XJ sport 4x4, rear drums from disk brakes. Stock except I am running rims / tires off of a Grand Cherokee.

Any thoughts on what it may be? What I should be looking for tomorrow?

 

sounds like a brake pad came loose and is moving around in the caliper then when you apply the brakes it holds it in place

 

Would that only make the knocking noise once per rotation?

 

i had one do so one time and it made the same sound you are discribing

 

jack the front up, and check the ujoint. that would cause the noise your describing.

 

same thing happened to me a month one of my pads came loose and they were bad too lol soo i just changed them on both sides

 

Also it could be that it seems to happen with the rotation. I have a similar noise in my cherokee and it seems to be my front u-joint. So check the pads and rotors then check other things (u-joint). With our jeeps it seems when something happens its from a combination of things and not just a single thing.

 

very true

 

I was thinking u-joints as well, but in the past when I have had the u-joints go bad it was more gradual. This came on suddenly yesterday.

I will pull the wheel tonight and have a look. I just moved from GA to NY and it is getting too cold to be working on this! For me at least. The weather we have now is what Jan would normally be for me. Need to clean out the garage to pull it in.

 

Cleared the garage so I could pull the Jeep in and work on it. Got everything set up, pulled out the tire tool to loosen the nuts. Got it on one and gave it a big shove.... Dang that hurt. The nut was loose and my hand hit the concrete hard. All of the nuts were loose. Tightened them up and took it for a test drive. All clear.

Also checked all the other tires and was able to tighten all of them some more. I think I read somewhere about having problems keeping Aluminum rims tightened. Will search and see what I find.

 

some alum. rims you have to check the lugs like every 500 miles or so or you could use a little gel super glue and it will keep them from loosening but not keep them from being glued permanently