jernigan

I have a 99 xj sport 4.0 4x4. Just the other day I heard a noise and it continues to happen more often. It only does it on a rough road or when you break hard, the noise sounds like a tire rubbing something. It sounds like its in the drivers front. I have looked over everything and I am clueless, you can push up and down on the front and no noises doesn't seem to have any play in anything in the front end. The jeep is all stock except for I am running 235-75-15 mud tires on it but they have been on there for about 10,000 miles.

BwanaBob

If you don't have a lift, or if you have sagging springs, 235 tires can rub when
breaking hard or bouncing around. Mine did. Mud tires make it more likely.
You can add coil spacers to the front and either get new heavy duty rear leaves
or add a leaf to the packs you have and you'll gain an inch or so be OK.

Martlor13

Why would that be? A mud and a highway tire in the same size will be, well, the same size lol.

also, if the springs and leaf springs are sagging, it's just best to get new ones. Spacers and aal would be just band aides that will just sag back in short order.

op go find somewhere to flex the suspension, park, and then see if you see anything out of norm

jernigan

It may be the tires rubbing but the noise sounds like it is coming from the driver front. Sometimes it makes this noise sometimes it dont.

BwanaBob

Check the sway bar bushings where it attaches to the frame. The bar
can hop around and maybe touch the frame if the holes are worn too big;
I would also check the bushings for the bottom of sway bar links. They
can make a clatter though probably not like a tire rubbing sound.

You could look for marks on the inside of the wheelwell flares for
signs of tire rubbing. Put some chalk on there, and see if it takes it off.

As for the noise, smoothed off passenger tires might make a tzinnng sound
when they rub. Mud tires are more bop bop bop bop that is hard to miss.

To see if you have any real spring sag, you can check your suspension
height by measuring from the wheel's axis up to the bottom of the fender
flare. Stock suspension should measure 17.5 inches in the front, 17 inches
in the rear. The Up-Country heavy duty suspension adds an inch to that.

IJM

Funny you should ask about this, as my '98 does the same thing under very hard braking. I also get it from the left front tire, and I'm running 235/75-15 tires. It does sound like the tire is rubbing on the inside of the fender, though I don't see any marks to indicate where it would be. I need to take it out and mash the brakes to get it to do it again and look more closely. As far as I can tell, it's still got the original front springs and shocks. I'll have to measure the hub center to fender height to see how much it's sagged.

jernigan

I knew that my rear leafs were sagging, but the front is at 17 inches from the center of the wheel to the bottom of the fender flare.

BwanaBob

Bad front shocks can certainly allow tire rubbing during hard braking.

Do you still have your front bump stops in place? They might be worn or
broken and let the suspension collapse too much (and you get tire rubbing
or damage a shock).

A half inch of front sag can be remedied by adding a 3/4 inch spacer to the
top of the coil spring. I wouldn't think you would need to buy new coils.

Martlor13

If you're going to go through the hassle of pulling the coil springs to put a spacer, Why not just replace them instead of band aiding if they are sagging. Thats just me though.

BwanaBob

You're probably right for guys who are in it to do their Jeep right
and keep it a long while. You have any recommendations for stock
spring replacements?

jernigan

I was driving to work this morning on flat ground and it started making this noise again and didnt stop all the way there. Sound didnt change when turning or breaking. I certain that it is not a tire rubbing , I have looked no skuffs on tire or anywhere in the fender of fender flare. I dont know what it could be, it had been getting worse but today I think its here to stay. I have never heard a bearing or a u joint make a sound like this, Iam off tomorrow going to take some time and see if I can figure it out. Luckily I have another vehicle to drive but I have got so use to driveing the jeep I dont like driving my extended cab 4x4 chevy. The jeep is so much easier to get in and out of parking lots.

BwanaBob

Brainstorm again.
Wheel U-joints can make different noises when they go dry or the needles fall out.
How are your motor mounts? Transmission mount? Does the fan ever hit the shroud?
Inner fender detached and hitting something?
Check the dust guards on the front brakes. Sometimes they make a noise.
Do you have ABS? Is the left front caliper not engaging correctly?
Sway bar link hitting a coil spring (sway bar not centered)?

jernigan

New motor mounts and trans mounts last fall, inner fenders have not fallen, have not checked the shroud, but it and the clutch fan and water pump were also replaced recently. I am not sure if I have abs but the entire brake system was replaced recently, rotors, calipers, lines everything front and rear. I am also leaning toward the u joints, I will check them out tomorrow, I hope that is what it is that will be a quick easy fix. Thanks for the comments, there is a lot of info on this forum I have found it to be very useful. It helped a lot when I did my motor swap last year.

jernigan

I think I found what the noise was, u joint in the axle was bad. I dont have it put back together yet to see if thats what it was but thats the only thing I could find. But I have never heard a u joint sound like that.

jernigan

Finally got it figured out, it wasnt to u joint in the axle but that did need replaced. I had a fuel vent vapor hose rubbing the front drive shaft. I am almost ashamed to tell everyone that, sometimes its easy to overlook the easy stuff.