Rattle in front end- Control Arm bushings?

[MAP]

I have a slow rattle type sound that comes from the front end. I ended up replacing the sway bar bushings and that eliminated some of the noise but it appears that it was masking the other sound.

This rattle only occurs when I'm going over bumpy areas. One bump won't do it. It seems to be coming from the right side.

I got under the XJ and tried moving all the control arms by hand but they don't move. The rubber does seem cracked though.

Do I need to let the axle hang by lifting the XJ at the body? Will this make a worn control arm bushing more obvious?

I also have noticed that the outer edge of the front right(passenger) side tire seems to wear more than on the left front tire.
The XJ drives straight though. There's no pulling. And the tires have ~40,000 miles on them so the wear isn't excessive but it is noticeable.

Any ideas? I grease all the greasable areas at least once a year.

What are the symptoms of a bad control arm bushing?

Thanks,
MAP

 

[rstarch345]

If you've got tire wear then that is indicative that you need a front end alignment. Since you have the wear and you have a rattle, it could also mean that you have a ball joint on the steering arm that is bad.

To properly check, you will need to jack up vehicle, remove tire (sometimes you won't need to, but best when you've never done it before) and using a pry bar, wedge it under each ball joint. Make sure pressure is applied on both sides of the ball joint. If there is any movement (other than normal), that's your culprit.

 

[rumblebelly]

How much ball joint movement is normal? Half inch, quarter inch, eighth inch? I have a little movement in my right ball joints. One mechanic said they should be replaced, another said they are fine since a little play is normal. I'm a little concerned since I recently slapped new tires on.

I have an occassional rattle coming from the right side and the first mechanic diagnosed ball joints. However the second mechanic noticed my caliper assembly had a little play which was the real culprit of the noise. The rattle stopped when brakes were applied. Might wanna check that out if you haven't already.

I have a slight thump coming from underneath my rig when I go over a bump. It can be felt through the floor. It's not bad but it got me searching underneath for anything loose. Couldn't find anything but I did noticed a little movement from where the bushings are when I "twisted" the control arm. Not sure if that's normal because it did it on all 4 control arms.

 

[rstarch345]

How much ball joint movement is normal? Half inch, quarter inch, eighth inch? I have a little movement in my right ball joints. One mechanic said they should be replaced, another said they are fine since a little play is normal. I'm a little concerned since I recently slapped new tires on.

None, zero, nada. You are an accident waiting to happen.

 

[rumblebelly]

But in your first post you said a "any movement (other than normal)". What do you mean by normal? Movement by other components? Sorry just a little confused cause I've previously had two different guys tell me two different things.

My 00 XJ only has about 81K on it. Is it common for ball joints to go out that soon? It handles great, if that makes any difference

 

[MAP]

If you've got tire wear then that is indicative that you need a front end alignment. Since you have the wear and you have a rattle, it could also mean that you have a ball joint on the steering arm that is bad.

Couldn't a bad control arm bushing cause tire wear as well?
I'd like to correct any problems before I get an alignment. I'm going to wait until I get my next set of tires which will probably be in less than a year or so at the rate I drive.
Like I said before though, after 40,000miles on a 50,000 mile tire, the tire wear is only slightly more on my right tire than the tire on the left side.
Also it's only on the outer edge.

I did my brakes a week and a half ago and didn't notice that the calipers were lose caliper. The braking is smooth.(had warped rotors)

That's when I changed the sway bar bushings and tried moving things around. I didn't pry the ball joints themselves but I did try wiggling the tire and didn't notice anything lose. I checked the trackbar as well.
I will probably try prying on the ball joints.

Can anyone tell me what symptoms you get when control arm bushings are starting to go bad, or are bad?

Any more thoughts would be appreciated.


Thanks,
MAP

 

[rstarch345]

rumblebelly,
What I meant by normal movement is the turning it performs. If it pivots, it's normal. If it moves side to side or up and down or any other motion than rotating, it's bad.

map,
I talked to the manager at the local Firestone store that does my alignment and his opinion was that before you would notice tire wear from the control arm you would feel a pull or vibration or clunking from the control arm. Inside or out side tire wear is from a worn component, linkage or ball joint, that puts the front end out of alignment. This guy is the only person I will trust to work on any of my vehicles and I have been dealing with him for over 20 years so I'm inclined to believe him.

Now since I have replaced three sets of ball joints on XJ's, I can attest that they are a major PIA. To have a dealer or shop replace them is going to be expensive. This might be why some mechanics feel a litte wear is OK. The XJ is a well built machine and will tolerate negligence probably better than most vehicles. To me, when it's worn it's worn and needs replaced. I understand the issues of being able to afford the repair, but when I seen accidents caused by people that wanted to get by just a little bit longer, I'm sorry, it's just plain not worth it.

Trying to track down thumps in your vehicle is tough. I have a complete new undercarriage that is just two months old. All by my own hands and I've got a clunk that I'm having a hard time tracking down. It's just a process of elimination and figuring out how to duplicate the highway while the vehicle is motionless. Not an easy task.

If you can grab your control arms and feel significant movement, then the rubber may be worn out. If you feel them clunk then the metal bushing is probably gone. The control arms primarily keep the axle from rotating and centered under the vehicle. Check this link, it may help http://www.heidts.com/heisinfo.htm

Don't wait to get an alignment. Many places it is less than $50 and if nothing else, they will tell you if there is a problem or not and you can decline to have them do the work. Very few places will charge anything up till that point. After I mounted my last component to make my XJ drivable with the new under carriage, I immediately went up for an alignment. I still needed an adjustable track bar and adjustable control arms, but I needed it to be safe till I did. A week later I got the parts mounted and got another. My life and health are worth more than $50. As far as that goes, I might end up damaging other components by waiting and my cost of replacement escalates.

Now if your not sure of the mechanics that have looked at your rigs and since I don't know your level of experience and knowledge, I might suggest you find an ASE certified alignment specialist. You might be able to get a better idea of what's going on from them.

 

[8Mud]

One sign of a weak control arm bushing is a thunk, when you apply the brakes. But this can also happen with a loose ball joint.
When I get a pop while turning into a driveway ramp, I usually think ball joint. But seriously, most any weak rod end will pop occasionally.
If you can feel a thump in the floor boards, one place to check is the rear of your tranny cross brace, near the cat., where the exhaust pipe goes over the cross brace and bends down a little to the cat, the clearance gets pretty tight. If you can't get a least a finger tip, between the exhaust pipe and the cross brace, it's probably gonna thump on occasion.
A rattle from the front while driving over rough streets can be the brake pads. Using a pad adhesive on the pad backs helps. A pad adhesive also helps eliminate brake squeal. On the early models there is an extra spring to apply a little pressure on the pads (anti rattle spring or clip).

 

[MAP]

Well, I'd like to think that I take pretty good care of my XJ. It's a 99 with 120,000 miles. I have a log of all the regular maintenance and modifications of done to it since I've had it over the last 5 years. I'm the only person to have ever touched it since I've had it.(I don't let anyone other than the guys changing tires and performing alignments touch my vehicle)
I grew up working on cars. My dad worked as a mechanic and in a machine shop so I've been exposed to car repair since I was young.

It is tough to track down something that is intermittent. There's only certain situations that create the rattle. I'll have to keep looking til I figure it out.


MAP

 

[rumblebelly]

Thanks Rstarch and 8Mud. If I remember right, I had about 1/8 to 1/4" of play when the first mechanic looked at it. He owns a reputable shop and after doing a little more research (YuccaMan's site), he's obviously right and they need replacement. That was earlier this summer too....The second mechanic, a friend, must have gotten sidetracked when he noticed the caliper had play and failed to check the ball joints adequately. I think he owes me a beer or two or three... I'll get it fixed asap but I probably won't ask for his help. Hell, maybe that's what is causing the thump when I pull into the drive. I know it's not the exhaust, there's plenty of space and it doesn't look like anything has been hitting.

Sorry Map for highjacking your thread. The discussion got me thinking and put me in freak out mode when Rstarch said I was an accident waiting to happen.

 

[8Mud]

I do a lot of dirt roading and hammer my front end parts pretty good. I keep an eye on things. The biggest factor is drivability. If it's stable and doesn't wander much, it's OK (probably). Though if enough parts are loose up front, you may get the wobble if you hit a bump just right.
Mine actually drove better with the bad front top ball joints, the little bit of extra camber actually made it more stable.

 

[MAP]

If you can feel a thump in the floor boards, one place to check is the rear of your tranny cross brace, near the cat., where the exhaust pipe goes over the cross brace and bends down a little to the cat, the clearance gets pretty tight. QUOTE]

8Mud, it's like you were reading my mind. I installed a Borla header several years back. It came with the pipe section that crosses over to the passenger side and over the cross brace to the catalytic converter.

I've never liked the clearance between the pipe and the brace. Also the hanger that came with the borla exhaust has a section of sheet metal bent in an upside down "U" shape the slides into the rubber area where the hanger goes. This upside down "U" has over time sunk into and cut the rubber.
I definitely think the pipe is hitting the cross member.

I need to loosen everything up and see if I can move the pipe a bit for more clearance. And I have to figure out what to do about the rubber piece where the hanger is supposed to go. I need to rig something to replace that.

Who knows... maybe that's the cause of the rattle/knocking.

I also get this clicking type sound under hard acceleration from a dead stop and that is annoying. I don't know if it's related. All I can do is replace one thing at a time and see if that makes a difference.

Thanks,
MAP

 

[Farrier]

Today I found my "rattle" and "growning" noises that came from the front left side of my 91 Cherokee.

The left end of the track bar is attached to a bracket that is bolted on the left side frame rail. Where the bracket bolted to the frame was very loose. You can get to the bracket bolts from over the top of the left front tire.

Best of luck

 

[MAP]

Today I found my "rattle" and "growning" noises that came from the front left side of my 91 Cherokee.

The left end of the track bar is attached to a bracket that is bolted on the left side frame rail. Where the bracket bolted to the frame was very loose. You can get to the bracket bolts from over the top of the left front tire.

Best of luck

Thanks for that info. Another possibility worth inspecting.

MAP