Did some searching and have a few places to start but didn't come across anyone with the exact issues as mine

Installed the Ome 2 inch lift a week ago. During that I also replaced all the steering rack bushings and front and rear sway bar bushings. Installed Sonoran stell diff drop too. Had the alignment done. They also balanced the tires. Didn't really have a reason to drive it around until I had a 80 mile round trip to do that was perfect to test everything out. Some highway, some up hill and some curvy downhill roads.

Everything was going great until the curvy downhill. When I started to notice a roaring sound I guess you could say. It seemed to completely go away when I went under 20 and would randomly start again when I was over 20. It doesnt seem consistent. Also seemed like I had a bad warped rotor under heavy breaking while going downhill before the roaring started.

Now it only happened for the last 10 minutes of the trip so I don't have a lot of information but I took my rig out for a quick drive this morning for maybe about 10 minutes while also reaching highway speeds and was not able to get it to happen again.

I've checked the lug nuts they are all torqued up. U joints and driveshaft are very tight. Cv joints seem ok. No play when moving from front of vehicle to back. But there is maybe 1mm of play in each moving from drive train to wheel. I checked the wheel bearings when I was installing the lift and they seemed fine.

The only thing I can think of is the Sonoran diff drop that I installed. I have the stock skid plate and didn't have the tools to grind out the part on the plate they tell you to to make some for the drop. So the skid is Snug against the diff. That might be causing the vibration I guess? But why only start near the end of the trip and that wouldn't explain the warped rotor feel under heavy breaking.

I'm going to go check it all out again and see if I missed something but I wanted to see if you guys had any suggestions. Thank you.

Check your axles, make sure they werent back together correctly. Grease your rear drive shaft as well. See what happens.

Yeah I need to go buy a new zerk gun. I'll will do that and see if it helps. On the 4runners there is a zerk for greasing the shaft is that right?

I also forgot to add that i dont have much aftermarket weight in the back. Only 50 extra lbs from a roof basket and the rear sits a little higher because of that. Not sure if that would be throwing anything off balance or not.

Yeah there's around 6 or so on the rear driveshaft. You can also grease the front but it doesn't run dry unless you use 4WD a ton.

6? That's quite a few. I saw the zerk for the yoke and right next to it a zerk for the u joint. Both u joints near the tranny don't have zerks. I'll have to look around for a few more on the shaft.

So I know Yoda recommendeds different types of grease for the u joints and the yoke. If my research is correct NLGI No.2 Lithium Base Chassis Grease is used for the universal joint, and NLGI No. 2 Molybdenum Disulfide Lithium Base Chassis Grease is used for the yoke. It's a huge pia switching out grease in a zerk gun and I'd rather not buy two. Is it important enough to not use one in the other? Or can I get away with using the same grease in the shaft related zerks?

I'm sure there are those who will say I'm wrong, and that's fine.

I use a high quality moly grease on all the driveline grease fittings at each oil change. I pump until some weeps out of the u-joint cups and wipe off the excess. The zerks on the slip yokes get enough to make the yoke telescope out just a tad. I don't overfill those.

I also hit everything with Moly B. Works fine. I still get some grumble from mine, but they're original 200k joints, so it's whatever. I'll change em someday.

I believe I saw a comment by you on another post saying the same thing. I ended up getting some moly grease and zerked them up. Will drive it tomorrow and test it out. Took around 15 pumps into the yoke before it moved.

When I drove it to the autoparts store the sound seemed to be most noticeable around 20-40 mph. It feels like a body vibration. I've read posts about the pinion bearing, panhard extension, and driveshaft extensions. If greasing up the driveshaft and joints don't do the trick what do you guys think the next step would be?

OP,
Any chance would be able to record video on this "roaring"? Im curious because I had a similar situation and ended up being wheels weren't properly balanced.

Driveline vibes are hard to track down. Get everything greased and report back. That *should* eliminate that portion as least. Then we can move on. A D/S bound up without grease will send NVH outward everywhere.

I can try. Its hard to distinguish from the engine as it actually sounds similar to a high revving engine. Even more so since i have the airaid mit and a snorkel.

The wheels being off balanced did cross my mind. I might take it back to les schwab and ask them to recheck the tires for me if it still continues.

Copy that. Will report back tomorrow.

I would start by fixing your diff to skid plate clearance issue first. I'd remove the skid plate and test drive again to see if the noise is gone. You might also check your rear brakes for evidence of the rear axle seal leaking into the rear drum/shoe area. That can also give you a vibration while braking.

The sound/vibration is still there after greasing up all of the rear driveshaft. It seems to peak at around 30mph. I will remove the skid plate and check the rear drums.