More Front End Popping!

Have front end popping or clunk issues with my stock '98 xj, w/160,000. When accelerating from a complete stop or slightly more often, just before coming to a complete stop, I will almost always hear one relatively loud pop! About half the time it can be felt in the drivers side floorboard and about half the time it can be heard closer to the passenger side. To a lesser degree it can happen when turning either direction at moderate speed as well. This just started suddenly happening several months ago and I am not experiencing anything else except the described routine pop.

Front brake job was just completed and it was hoped the repair of the knuckle notches from pad wear would take care of the issue. Alas, although reduced, they still remain and eerily similar in volume and metal to metal feel. In trying to find the culprit, I have worked through all known potential causes listed extensively in other threads with no solution as of yet.

Mostly by elimination, am suspecting control arm bushings, only because everything else seems to be fine and dandy and am getting noises in braking or accelerating situations more than in steering situations.

After bench inspection of the lower control arms and bushings, they seem to be original to vehicle. Although there is minor cracking, rubber seems firm with no ovalling to speak of, although rolled inner sleeve and bolt seem to have excess clearance when mated and sleeve itself seems out of round.

Since I do not have extensive suspension repair experience, what visually or otherwise constitutes a worn-out CA bushing and even after installed and properly torqued, could excess clearance between the inner sleeve and the bolt cause a pop as described in this thread and other threads with bad CA bushings?

Of course, if there is anything else that I may have overlooked, feel free to chime in.

Thanks

I get a popping when my johnny joint on the JKS track bar needs greased. Normally I keep up on it but once in a while it starts going pop pop pop.

Maybe your stock track bar is worn out...?

In recent weeks, I have replaced my aftermarket RE lower control arm bushings, D30 upper control arm bushings, and front/rear RE leaf spring bushings. All of these were excessively worn due to trail use and caused pops when accelerating/decelerating and rolling over curbs and small foreign vehicles.

Check your steering bolts, tie rod end, track bar, and other suspension bolts. My RE steering drop bracket caused popping during turns and over curbs as well. Get in the habit to check torque often.

Damned LOUD Poppings anyways! Had same on mine, but mostly to the driver's side, and on mostly left turns. Turned out it was my stock track bar puking out at driver's side, but did not find it until I hit a hard water filled pot hole.., made a visual inspection and noticed the zert stripped out somewhat, could not screw it in, or out, just kind of dangled. (Had recently greased it, the pressures of the 'hit' were too great). Then came the 'death wobble'. Replaced track bar with one from kevinsoffroad. Could be your track bar is 'dead' at both ends, hence the results you describe. Sure hope you give feed back when you correct the problem so as to let us all know!

Just had the same issues with mine that gradually became worse.

Have you checked the shape of your U-joints of your axles shafts? Mine had some slop and were on the verge of exploding at any moment.

Replaced the joints...problem gone!

/\ true. I did this a while back. It's a bitch of a job in the rust belt, lots of quality time with a propane torch, hammer, and PB Blaster. I ended up knocking the ABS rings off the front axleshafts while removing the u-joints.

I wonder if non-ABS front axleshafts use better u-joints?

use greaseable u-joints for long service life. You can flush the water out with grease after playing in the dirt/water out on the trails. 'heavy duty' u-joints are non-serviceable, however they are solid and can therefore withstand higher torque. If you get them contaminated with water though, you're SOL. I prefer OEM (Dana Spicer) units, or Napa units. I forget who makes them for Napa, but it's a good brand that supplies the factories. Federal Mogul?

When the control arm bushings were wearing out at the chassis end on mine, I could feel the 'pop' by my feet. When they were wearing out at the axle end, I could hear, but not feel the noise.
When the trackbar bushing was dying, I could usually get a noise by turning the steering wheel from lock to lock while the vehicle sat still. Of course sometimes other issues with tie rod ends or loose parts can be the cause, so a good inspection while someone turns the wheel helps.
It also helps if everything is greased/lubed and tightened properly.