Click/bang in front end (xj)

[blistovmhz]

98 XJ, 6.5", 33x12.5R15, WJ knuckle swap, OTA/OTK steering (1 tonne), D30hp/D44, front/rear auto-lockers, long arm, np231 (SYE).

I've had this noise for as long as I can remember. I believe it was happening before most of my mods, but it may have been the track bar before, and now I can't figure it out.

When wheeling, every once in a while (every few minutes) I'll be articulating at odd angles and there will be a very loud pop/bang in the front. I've checked everything I can think to check in the suspension. Track bar/joints/mounts show no signs of movement, TRE's and tie rod/drag link are all tight, pitman arm is tight, ball joints are good as far as I can tell, and the steering box doesn't seem to be moving. Front axle shafts were just replaced with some chromoly, and new spicer joints.

Everything in the front end is brand new. The pop/bang sounds exactly like a track bar moving around in a lobed out mount, but I'm positive that isn't the source. Only happens during articulation changes, and seems to happen more often when wheels are slightly turned.

I didn't think to try in 2wd yet, but that, and sticking a camera under are the next test.

All I can think is that this is just the front locker loading/unloading. Torque while climbing, fully loaded, then when I start dropping off an obstacle with one wheel, it unloads and bangs. While this COULD be the source of the sound, I'm not sure how likely it is. I've never heard this sound coming from another vehicle and it not being a suspension issue.

Idea's?

 

[Jays siik xj]

Mine does that when the coil gets unloaded and moves away from the upper spring mount. Dunno if that's whats what yourr hearing but Its an option.

 

[blistovmhz]

Mine does that when the coil gets unloaded and moves away from the upper spring mount. Dunno if that's whats what yourr hearing but Its an option.

It SHOULDN'T be my coil, as my shocks limit droop enough that the coil retains a little bit of tension at full droop. I do however, notice that the coil does bow out a little and rub on the track bar mount. I suppose this could be it, but doesn't sound like what you'd expect from a coil hitting something.

Will make sure it's in the video.

 

[Gary Briggs]

I had a similar problem/noise. My adjustable track had a slightly smaller bolt than the stocker did, over time, the bolt moving around had opened it up even further almost to an oval shape. To fix the problem welded a grade 8 washer that fit that bolt nice and tight over the stock mounting hole. Problem solved!

The hole wasn't more than a 1/16" oversized, you would think that would result in such a loud noise. But sure as shit it did!

 

[blistovmhz]

I had a similar problem/noise. My adjustable track had a slightly smaller bolt than the stocker did, over time, the bolt moving around had opened it up even further almost to an oval shape. To fix the problem welded a grade 8 washer that fit that bolt nice and tight over the stock mounting hole. Problem solved!

The hole wasn't more than a 1/16" oversized, you would think that would result in such a loud noise. But sure as shit it did!

As I said, it's not the track bar moving around in the mount. I built the entire front end myself, from the long arm cross member, all the way to the steering. I know the sizes and tolerances of everything, and as far as all my testing goes, everything is tight. It's gotta either be something I didn't build myself (ie: maybe the steering box bearing is loose, or the frame rail is cracked, though I can't find any evidence of either), or the locker is making the noise, or the coil is hitting the track bar mount (which seems like the most likely, just doesn't SOUND like the sound I'd expect).

 

[yossarian19]

Also possible, steering box bolts / spacer issues?

 

[Ivan]

It SHOULDN'T be my coil, as my shocks limit droop enough that the coil retains a little bit of tension at full droop. I do however, notice that the coil does bow out a little and rub on the track bar mount. I suppose this could be it, but doesn't sound like what you'd expect from a coil hitting something.

Will make sure it's in the video.

What it sounds like, is that your coil bows out more under compression, grabs the trackbar mount, then unloads with a bang when the coil slips off.

Check where your coil and trackbar mount rub. Or put you XJ up on jacks, remove the wheels, and cycle your suspension to see what is happening....

 

[blistovmhz]

Tried reproducing the issue in the shop, but never happens. Only when wheeling .
I moved the axle over 1/2" today which does bring the coil out a little farther from the mount. Will test tomorrow.

I'm helping my roomie build up his k1500, which should be done in the next few weeks, and we'll be taking both trucks to the shop to play with the fork lift. Maybe find something there as we'll be able to pick it up and drop it a few times while watching.

I did check the steering box/bolts/spacers. didn't actually pull the box off, but it shows no signs of movement.

 

[ColoradoRaptor]

What it sounds like, is that your coil bows out more under compression, grabs the trackbar mount, then unloads with a bang when the coil slips off.

Check where your coil and trackbar mount rub. Or put you XJ up on jacks, remove the wheels, and cycle your suspension to see what is happening....

Ding ding..... I think we have a winner.