I have read most of the sound chasing threads and so far I can't pin it down based on the responses others have described. Not knowing what a cowl crack sounds like, I will try and best describe my annoyance. At low cruising speeds is where it is heard most. It is brought on with the drivers tire hitting a divet on the road, or even the street glue down reflectors. It is a chatter noise somewhere under the dash directly at the furthest left, like by the drivers kick panel. It is a metallic chatter. I have checked all steering related items for looseness, including tie rod bolts. Seems when I round a corner at around 25mph it is most evident when the steering wheel gets halfway turned. Shocks are tight, leaf spring hardware, castle nuts that attach drag links, etc. The steering gear box is mounted and torqued to a new stand off plate to the frame so I'm good there. It is something directly in line with the drivers side A-pillar, under the dash. Any thoughts?

 

Sounds like a wheel bearing if it happens when you are cornering. Otherwise did you check the parking brake cable?

 

Well that would definitely be the area where the cowl cracks seems to be. Without removing the fender it is hard to diagnosis this as your problem.

You might be able to get a small flexible LED light....I have one for getting into small, tight spaces...and look up under the edge of the fender. Might be able to spot some of the cracks?

You could also try and look up towards the cowl, when the door is open. You might be able to reach up and feel the area as well. Might be able to feel the cracks?

But if it is cracked...this could be what your hearing as the body flexes and rolls. How are your body mounts?

 

Body mounts are original. I have a set of the entire energy suspension kit at home awaiting time for me to install. As far as wheel bearings goes, I replaced them with new during the summer so they are about 6 months new. Other than the standard way of seating them when re installing the hubs, is there anyway to check w/o re dismantling the hubs? I followed the bc847 sticky pic by pic and word for word when I redid my front brakes. Except for calipers, everything was installed new

 

You may be able to take the left kick panel out and use a light and a mirror to check for cracks there still may be some you can't see though..

I would replace the bushings and see if that cures the problem. If you are going to do it anyway what can it hurt?

 

I would suggest that you start your rig, set the parking brake and grab the steering box joint. Turn it back and forth (or have a partner turn it back and forth), and see if the steering box is moving in relation to the frame. If it is, the bolts holding the steering box to the adapter plate could be loose, or the adapter plate could be broken. Mine all seemed good, except there was a noise similar to what you describe, until I did this and my steering box was moving. It turned out that 2 of the bolts were only finger tight...Mark

 

Check the spring and wedge that hold the caliper. Mine came out and made a rattle because the caliper was bouncing around on the mount.

 

Metallic scratchy sound when going into turns, or over bumps...


YUP.... Cowl cracks. Sounded exactly like that in my truck.


Good news is that to take the fender off will take less than an hour if you're careful and have a good knowledge of the process.

I took all day with mine, as I cleaned up rust and sprayed everything I could with rust converter, and then a top coating of cold galvanizing spray. I think welding / fabricating the repair metal took the longest out of the whole process.

Oh, yeah. Finding someone else to hold the hood so I could get a couple bolts into it without scratching the crap out of my truck....

 

Thanks for all the advice, all. I will try all reccomendations, and save cowl crack for last. As far as the steering box area with the mounting plate, I just replaced that 3 weeks ago with a brand spankin new one. I realize it is a discontinued part. Got lucky with that one. Back in 2009 or so I went to the dealer to buy the bracket that mounts on the inside of the frame, the one with a brace to keep the frame from twisting. The dealer sold me the wrong part. As I unwrapped the package at home I cursed them for selling me the wrong item, but decided to keep it anyway. Lucky I guess. Will get back to you all when I find the sound fix, so as to possibly assist others

 

Hey, all. Curious about something, which I may think may be where the noise is coming from, based on my original post descriptions. Are front calipers, the area that holds the outer brake shoe, suppose to have a little play back and forth with it? Like 1/4" movement? Reason I ask is I pulled off my drivers side front tire and took a rubber mallet to tap around looking for looseness anywhere directly below the A-Pillar in search for that noise and noticed slight side to side play. The allen fastener that holds the keeper tab that holds the caliper assembly is intact, but don't know why I have slight play. Grabbing the entire caliper assembly and trying to shake it, it feels secure, but wondering about the side to side movement. Seems like it needs some sort of shim or something. Is this normal, since this direction of play is what would move when applying the brakes? As far as a loose wheel bearing, how does one check for that? Thanks for the advice so far

 

IIRC there is supposed to be about .060 between the caliper & slides. That's just under 1/16 of an inch, FWIW. You can buy oversized keys to take out the slop -- but I have only seen them listed for the gm application (1986 K35). I have them on both sides of my truck. I don't know why this info isn't in the sticky -- I learned about them here.

 

There's a spring that's supposed to be in there that's probably missing. (Post #7 )

The Allen head bolt holds the "wedge" in place, then there should be a spring that looks similar to one leaf out of a leaf spring and that should be between the "wedge" and the caliper.
The spring is probably gone and leaves all that slop for the caliper to bounce around on bumps and when applying the brakes.
Eventually, It can wear enough for the caliper to fall right out and hang from the hose. Ask how I know this.
And last I checked those oversized wedges were pricey but I should have bought them, cuz now another one of my springs is gone.

 

Allright, I am going with the 1st step on swapping out the wedge key that was made oversized for the GM that Alec and MARF75 suggested. Wasn't bad in price from O'Rileys. $20, and in the package comes 2 wedge keys, 2 tension springs. Both those I understand how they mount. What also came, which baffles me, are 2 clips. What are those for? When I replaced my pads a few months ago, I never saw those clips anywhere. For comparison, I asked counter guy to look up the ones for our trucks and those also came with those clips. One more question. In the shop manual it suggests hammering over the flanges(tabs) on the brake pads so they somewhat don't fit too sloppy on the caliper, I did not do that to the new ones. Is that a bad thing...like could I have shortened the life span of my pads? That could be causing that rattle, you think? Doesn't seem like that noise would carry onto the underside of the dash/A-pillar but I could be wrong. Let me know your thoughts on the clips, and pre bending those brake pad tabs, ok. Thanks for listening

 

Those 2 clips are for the pads . One for each pad, goes on the bottom ear to take up the slop and keep the pad pushed up tight in the caliper so when you apply the brake the pad doesn't "slam" up against the caliper.
Not a very good description, but I hope it helps.

 

Ok, a success story. Finally after a year of rattling noise coming from drivers side dash close to the a-pillar, I finally got it resolved. I wanted to share in case anyone else on here has been badly discouraged with the same problem. First off, I did attempt all the suggestions offered here and came up with an unresolved issue. I went as far as checking my wheel bearings for looseness. I even shot foam spray(expanding)into the cowl area through the alley above the door hinges.(By the way, that seemed to tighten that area of the cowl, making it less hollow). So after all this, it turned out to be the 3 bolts that hold the windshield wiper arm shaft, which can be accessed by removing the grate that all the leaves fall through below the windshield. Also directly under the corners of the windshield are nuts attached to bolts which I believe secure the quarter panel/cowl. All those were loose. Not finger loose but loose enough to allow me a whole turn with the wrench. Noise all gone. Thanks all for your input