Front end suspension or driveline rattle/clicking diagnosis (1 Viewer)

[JS114]

I'm at my wits end...

I have what sounds like something about to fall off from the front left side. More of a rattle than a clunk. Happens equally when under power, coasting, or braking and there's no difference if I'm steering left, right, or driving straight. It occurs at all speeds, but the slower I'm going, the easier it is to hear. It's most noticeable on slightly rough paved roads. I don't hear it all on a perfectly smooth road and can't tell it's there off road. I may be able to feel it too under my left foot, but I'm not sure. Bouncing on the sliders, I cannot recreate the noise.

I've so far, to zero effect:

• repacked front bearings
• replaced front shocks
• replaced front sway bar components
• replaced rear sway bar components
• inspected both fenders, fender liners, engine compartment, bumpers, lights, etc for rattles
• checked all fluids and all look good
• driven on road with t-case in Low
• balance and rotate

I have had pfran bands on my CVs for 4 years and have no CV symptoms or leaks. There is the same vertical and horizontal play in both front wheels when I jack it up and give them a shake.

It's unlifted, but the torsion bars were cranked 5 years ago to level it a bit.

 

[labcab]

Heat shields?

 

[JS114]

Checked those first...all appear tight. Steering is tight too; I've spent the past 3 hours on this...drove it on gravel, activated ABS, cycled center diff lock, no luck.

 

[labcab]

It gets difficult diagnosing squeaks and rattles that can't be replicated with the truck standing still. Normally, I'd advise against throwing parts at it, but with my truck at about 250K, I've found half the stuff up there needs replaced anyway.

So depending on your mileage, you might want to go ahead and replace the ball joints and bushings on the control arms, and steering rack bushings are cheap too.

As @Trunk Monkey always suggests, go ahead and get a mechanics stethoscope for $4 at Harbor Freight. It may not help on this one, but it will come in handy eventually.

Figure out a consistent way to replicate the issue. Ideally, standing still, but if in motion, then as slow as possible. Find a speed bump or a stretch of washboard road where someone can drive your vehicle past you sitting on a crate. As many times as it takes to get you pointed in the right direction.

 

[JS114]

Today, for the first time, I observed the noise at a stop. I was facing slightly up hill. Not only did it occur, but I observed that it started and stopped when I leaned left and right in my seat. I got a short video before the light turned green. Differential? Torque converter? It is a pretty deep rumble, not a vibrating heat shield...

I took the skid plates off, but didn't see anything obvious. Greased the zerks to no effect (on this, unrelated start/stop clunk is gone).

 

[planomateo]

Kinda sounds like the issue I'm having, but hard to tell from your short video clip. Here is the sound I'm referring to, ignore the brake squeak .

I haven't messed around with it in a few weeks, might dig into it during the long weekend. Might be as simple as a bushing in the LCA.

 

[labcab]

Today, for the first time, I observed the noise at a stop. I was facing slightly up hill. Not only did it occur, but I observed that it started and stopped when I leaned left and right in my seat. I got a short video before the light turned green. Differential? Torque converter? It is a pretty deep rumble, not a vibrating heat shield...

I took the skid plates off, but didn't see anything obvious. Greased the zerks to no effect (on this, unrelated start/stop clunk is gone)...

Now that you can replicate it sitting still, you'll need the stethoscope. I had a hole in my exhaust that sounded similar to your video, but it was constant. I've heard of the high/low shifter creating some odd noises and vibration in the cabin. Engine cover too. It will cause some strange vibrations when the foam wears down.

Once you can replicate it consistently:
Keep peeling off parts to isolate it. Now you know it's not the splash guards and have better access to poke around. Serpentine belt is another good one. If it still makes the noise when it's off, then you know it's not your fan, alternator, PS pump, etc.

I also use the controls to rule things out. e.g. turn the rear heater off and on. Rules out the fan under your seat and that it wasn't stuck in the on position or anything. Power down the stereo, turn the AC on/off, replicate the noise in both drive/park.

 

[2001LC]

Have you eliminated your seat.

 

[JS114]

It's tight, but I didn't know there was a fan under it...something to check tonight.

 

[2001LC]

Rocking in seat wouldn't cause much movement of suspension. But if not your seat you just isolated to suspension. Get out the stethoscope and have a helper (of your same weight) rock in seat under same conditions.

 

[JS114]

I'm throwing in the towel. I went up into the mountains on some forest service roads yesterday with my kids and it sounded (but didn't feel) like the wheel was going to fall off. I've scheduled an appointment to have ACC look at it in a few weeks. Glad to have them local. Will report back what it is.

 

[WarWagon]

The wheel? Maybe a wheel bearing.

 

[brianrride]

I had a similar issue that made it sound like a wheel was literally about to fall off. Replaced LBJ just certain that was the issue. Did not fix it.

It was my lower control arm bolts - they were probably only torqued to 100 ft/lbs when they call for 170. Torqued them to specs and issue resolved.

 

[Julian Stead]

It does sound like something around the control arm bushings, loose bolt or worn bushes. Try and rock the vehicle side to side to replicate and keep an eye on the lower and upper control arms movements.

 

[JS114]

I've verified torque on control arms and what I can see of the bushings are still pliable. There is some play in the differential support when I put a pry bar on it. Very similar to this video @2000UZJ posted. What I can see of the bushing doesn't look obviously damaged. Can someone tell me what "normal" play (if any) would be in this? It didn't take much effort with the pry bar to make it move. 240k miles...but I hate to just throw more parts on it without being reasonably sure.

 

[JS114]

Resolved!!!

I'm almost embarrassed to admit that I solved this mystery after almost 6 months. My WKOR sliders had either shifted up or my body has settled down just to the point of occasionally touching. There was clear evidence of rubbing on the DS fender liner (which I've now trimmed) and I lowered the sliders a 1/4". What a relief to have solved it. Frustrated with all the parts I threw at it for no good reason....