for the longest time now i've heard a deep groan when the suspension is flexed even a little. pulling up into a driveway or crossing any sort of dip at an angle... it almost sounds like slow speed tire rub (but it isn't), but only metallic. i cant think of anything else near the area i swear i hear it from except the double cardan joint, sometimes i can feel it too. anyone have any insight?

Check the tie rods and sway bar bushings.

I'll check them but I'm 98 % sure its coming from the center and rear of the truck. It may be in my head but it seems to give additional rolling resistance when it happens.

Yours is 2 wheel drive correct?

If that is case you have no double cardan, instead, just two replaceable U-Joints.

I have a 4wd Sr5, also sway bar bushings and control arm bushings look good.

Oh I see now, I just glanced at your sig really quickly.

Is it lifted at all? When the driveshaft contacts the gas take during articulation you will feel/hear a grinding. It also causes the driveline to bind

Couldn't resist, my apologies.

Not lifted but I'll double check for contact. It does it when I'm driving on the street too, just going over a mildly ridgy intersection or small speed bumps. I think I'm going to have wedge myself under there and ask my wife to drive around lol.

I have the same noise in my truck, although it is seasonal - stock suspension with 194k. Mine likes to annoy me when I am backing out of the driveway - I just heard it for the first time the other day after not hearing it for months. I believe that it is the swaybar bushings.

I just traced my mystery noise to the double cardan last week. It was driving me crazy that I couldn't figure out where it was coming from. Since I could only hear it when driving, I wrapped my phone in some packing tape, put 4 magnets (use neodymium, and you won't have to worry about it falling off) and wrapped it again in more tape. I set the phone to record and stuck it to the frame rail. Went for a drive and listened to the recording. I had to move the phone to a few different spots before I was finally able to pinpoint the source. It was ridiculous how loud the noise was when the phone was near the cardan joint. I would recommend using a cheap digital recorder rather than an expensive phone, but at the time, I just didn't care, I just wanted to find the source of the noise. Good luck with it.

For me, best way to be sure is to grease all your joints, slip yoke and the carden ball. There should be 5 total zerks to grease. I did this and my sound away. That's how I knew it was my driveshaft. I recently had mine totally rebuilt. The double carden is a major pia to do yourself. And Toyota says to replace with new drive shaft, they won't rebuild it. Good luck.

The double cardan joint on my 4Runner was making a ratcheting sounds in 1st and 2nd around 19K-23K rpms. Using a chassis ear I mis-traced the sound to the transfer case which is the closest part to the driveshaft I could clip a mic to. I didn't figure out the DC joint was bad until my whole truck began shaking bad going above 60mph.

I recently had a mystery noise and it went away after I greased just the center joint behind the transfer case. I've heard it's best to just take the job to a gear and axle shop for a rebuild.