Suspension noise - starting and stopping

I have a strange knock/popping noise when I accelerate or come to a stop. If I don't hear it when accelerating, it will sound off when accelerating around a corner.

I tried to bounce the vehicle without sound. I also checked everything to look for cracks or loose joints, but this happens under load so it would be hard to replicate. I had a tie rod break on me once and the sound is nearly the same but the replacement looks good.

Can't tell if it is coming from the front or the back, left or right side. The noise is transmitted through the body so may be hard to hear outside.

Don't know if it might be a broken leaf spring. Couldn't see any cracked ones. The front Sway Bar bushing is worn out so it might be that the bar hits the mounting strap. Not too confident that is the problem though.

Could it be bad control arm bushings?

How about brakes?

Comments?

I had this happen a few different times, and it was a few different things... the first time it was the oem shock....the metal dust shile was clanging around, because the shock had gone bad. Take a look at all of your shocks, and the mounts....REAL close.... with the standing weight of the jeep on them, they may look fine, but may be unseating just enough when you go around a corner. I also had an issue with my front sway bar. The frame mounts were wallowed out, and it was giving me some noise over bumps. The other issue I had was my double shear track bar.... the mount needed to be torqued down SUPER hard.... i would hear it "float" sometimes, and give me a clunk every now and again. (this float was prob less than .050" but it sounded alot worse.) I would look at both of your track bar ends, and make sure that they are not only mounted securely, but in good condition. Take a look at the drag link coupler, and make sure its nice and snug. Check your lug nuts. Check your caliper bolts, and take a look at the spring retaining clips on the front axle. I would also look at all of your control arm bushings real good. Have some one work the steering wheel back and forth on dry level pavement, and look over all the rod ends, (tie rod, drag link, track bar - and also the control arm bushings) -you shouldn't see any movement. As for the rear, make sure your leaf spring eye bolts arent loose. And check your U-bolts at the axle. You have a lot to go over, but with due diligence and a friend to help you should be able to track it down. Good Luck!

Thanks for taking the time to list the possibilities!
I installed the track bar only a couple of years ago but I will double check the ends. The shocks were install maybe a year earlier and are Monroe Sensatrac. I will check those as well but I know they are still functioning properly.

This is not a clanging noise. I suspect it is a .50 gap that is being worked. It takes hard acceleration to get it to pop.

What is a double shear track bar?

My '96 suffers from axle wrap. More than a gentle stop, and the axle wants to rotate with the wheels. Let off the brake, and it clunks back to normal. I mostly cured it with leaf spring clamps, but the main leaf is tired. A replacement would cure it, but I'm not looking forward to fighting with the front bolts!

This is, of course, if the noise is in the rear...

Worn sway bar bushings can cause all sorts of noise. Replace all the bushings and see what happens. Probably the cheapest, easiest fix on the car. And if you know they're worn anyway...

So I had my wife "rock" the steering. Two loose joints. The track bar at the axle end and a TRE. But I am confused on nomenclature. Will need to look it up.

The sway bar bushings are in the mail.
I was thinking I should just replace them all as I have over 207,000 miles.

I also am interested in the construction of these joints. Is the track bar end at the axle repairable? I found a site that talks about the repair using Energy suspension parts.

For a street driven vehicle, you're better off to use OEM type bushings. The axle-end bushing of the track bar can be replaced, and it will be easier to do if the bar is out of the vehicle. And if the bar is out, why not just put in a new one? In my experience, the ball joint at the frame end usually goes before the rubber bushing at the axle end. I will remove the track bar and mount, chuck them in the vice, and then remove the cotter pin and castle nut inside the mount. It's just easier off the vehicle...

Maybe a urethane bushing wouldn't hurt at the axle end, but beware. I had a full urethane front end on my '92. It handled super-no 'Jeep wander', precise steering, etc, until you hit a bump. Then all hell breaks loose! The energy has no where to go, so it just reverberates throughout the whole front end, then into the car body. Not the hot ticket for crappy roads here in Northeast PA. One by one, I started replacing parts with new OEM style pieces, the last piece being the Kevin's track bar with rocks for bushings. Now, finally, it's happy. So, the best advice I could give, is use factory type bushings and part, preferably good stuff like MOOG. Companies employ ride and suspension engineers for a reason.

Good information about energy distribution. I hadn't thought of that!

I was back and forth on this forum with a doctor in England having the exact same symptoms I'd had with my '92. He swore up and down that the hard bushings couldn't be the problem. And, it was cost and availability of stock parts across the pond, not to mention a doctor's schedule, that kept him from experimenting. He started the thread asking a few questions, and after a few weeks, it was down to just the two of us, back and forth. He finally bit the bullet and got hold of OEM control arms and a track bar, and he got back to me admitting that I was right. I'm no engineer, but I've had XJs for a long time, and my son and I each own two. Yeah, we experiment with various suspension parts, lifts, etc, but with each of us, the ones that bring home the paychecks are STOCK. If you've got an extra one for a rock crawler or weekend warrior, shoot for the sky! But have a lift on knobby tires, and have to swerve quickly at Interstate speeds, and when the pucker subsides, you'll gain a new appreciation for the engineering in a well maintained stock XJ.

Well, I am an engineer and understand that there is a reason, more so than not, for the selection of materials with specific mechanical properties like durometer spec. See I can't evens spell, just like an engineer!
I ordered a upgrade kit from Kevin. My plan is to use stock parts for the rest of the steering linkage as needed. I do want to lift at some point in time and his system makes the linkage from the frame to the axle nice and solid. The drag link bushings will be stock along with the sway bar.
It wont arrive for another week. If there are those interested, I will post results.

I put a Kevin's track bar on my '92 back around '04. Real nice piece, and he's great to deal with. When he found a problem with the hardness of the bushings supplied with the kit, he got hold of me, and asked if I'd like to try the replacements! Amazing customer service. At the time I thought the track bar was the source of my vibes, it turns out it was the stock control arms with Daystar bushings. I replaced the arms with Rubicon Express adjustable arms, the ones with a spherical joint at the body end, thinking I needed to go harder! Like I said before, the handling was fantastic, as the axle had NO lateral play. All that changed was the frequency (Hz) of the vibe/shudder/madness. I had an unfortunate incident with the car, and over the ensuing two years as we rebuilt it, I went back to new, OEM control arms, and finally the track bar. Now, it feels like a brand new XJ, at 205k miles! Like I said, engineers earn their money!

And, I have over a thousand bucks worth of not-so-used suspension parts under the workbench, waiting for me to drag home an MJ to go crazy with. Well, I do need a truck...

Good background info. I am seriosly considering replacing the control arms with OEM style. I am limited in space, time and tools to do the work. based on other threads, replacing the bushings in the control arms may be very time consuming.

This is a west coast Jeep so the underbody has not been exposed to any salt conditions during the winter nor has it been driven on the beach of the Pacific very often without being washed down afterwords. In additons the special undercoating of engine oil, transmission fluid, brake fluid and anti freeze has done a good job of preserving most of the front!

I have read about someone who welded the control arms with plate to make a box. Thought this was really stupid as this just moves the stress to another componant that would not be nearly as torsionally compliant, inducing early and possilby catistrophic failure. This is true with body "stiffeners" as well for a unibody that was designed to be flexable without failure. Non-compliant stiffness is not the goal!

Appreciate your informaiton

Got my Kevins trackbar installed. Much better steering without the axle sliding left and right! Still have the popping. Ordered ZJ DragLink/TieRod kit from Kolak - best price without dealing with local shops and parts.
I think I finally figured out why the noise. If the problem is loose TRE's then the popping is the movement as the toe changes from stopping and starting. I think the failed or worn TRE allows the toe to change and the popping is the movement from one extreme to the other as the vehicle is either accelerating or braking. We will find out when I get it installed.
The other thought is the movement based on the control arms being worn. I have located used set of stock UCA and LCA"s with 80K miles on them from a TJ. Don't think I can go wrong with $10 for the set! Gotta be better than the set on there now with nearly 110K miles on them.
Oh, did I mention this became a problem after loading the jeep up with stuff after putting it on a dolly and towing it across country?

I had that problem twice, once was loose lug nuts, the other was the front drive shaft u-joint, both made the noise, only while accelerating into a turn, especially turning and moving up hill in a turn, like into a driveway or parking lot.

heyhar said:

But have a lift on knobby tires, and have to swerve quickly at Interstate speeds, and when the pucker subsides, you'll gain a new appreciation for the engineering in a well maintained stock XJ.

Click to expand...

LOL!!!!

I already checked the lug nut issue. One of the first things to check and it is different than what I am experiencing. I will check u joints. I don't get pops over bumps or up driveways but do get them on turns while accelerating. If I accelerate slow then the pop happens later like it takes a certain amount of force for it to pop.

So far everything really needed to be replaced anyway so no loss of $$. Not to sure that the xCA's need replacement.

Mine was under acceleration in a turn only, just seemed louder if it was an acceleration turn up and into a driveway I think. But it took both acceleration and turn. I thought it was my rear end going bad. and it sounded like it came from the rear, which made it harder to locate. I fixed it about 4 years ago, so I know I found it. If it had been a front wheel drive car with C-V joints, I would have suspected C-V joints, but the jeep noise, IIRC, was more like a single click, and not a click-click-click like a C-V joint if that makes any sense. Been a few years now, but I recall have trouble finding the damn source!!!!

I had a problem from start and stop. Pretty much at the very end where the vehicle rocks. It was the slip joint in the drive shaft. Lubed up and it went away. It could also be the slip yoke in the transfer case if you don't have an SYE.

Update:
Installed new draglink/tie rod from Kolak. Nice steering, not too tight but just right. Still have the problem. Double checked the ball joints but they feel fine. Still wondering about the control arms.

In the mean time, the key stuck in the lock position of my drivers door! Can't unlock the door and you all know how much fun it will be to try to get in there to the lock cylinder with the door closed!