I need some help on this one.. My 4Runner (2010 Limited 4WD, 193k) gets this strange steering wheel vibration that grows with engine load. Its not directly by RPM. I can be cruising at 4000RPM and it won't vibrate much until I give it more throttle. It really does it bad during engine breaking though. If I take off normally from a stop light I barely feel it, but if I accelerate a little bit I feel a growing vibration in the center of the wheel as the engine increases RPM + HP due to the RPM. My front wheel bearings are new, my driver's side CV axle is new. I replaced the bearings preventively and the CV Axle addressed an issue with vibration and clicking while turning or moving from a stop. I hoped it would fix the big issue and it did not. I suppose I can't say I've "tested" the passenger CV Axle. It doesn't seem bad though.

I greased the drive shaft and U joints the other day and it seemed to get a little better, but those had never been greased before in 100-190k miles, per the previous owner. Its strange because power delivery is smooth. Its not like the car hops or shudders.. Just vibration. It doesn't do it while coasting at any speed only under load. No vibrations at idle. Maybe U joints? The driveshaft didn't seem to have play when I went under and shook it around but that's mostly what I suspect. The truck runs well and I like it, I just do alot of my own work on my trucks and like to fix wear items before they become real problems. This one has me stumped without completely removing my driveshaft and checking it out then.. My current solution is just not ever giving much throttle lol

Any thoughts? Experiences?

Tires could be out of balance, swap the rears to the fronts at correct psi and see if it helps. Bushings could be toast. Sway bar bushings control arm bushings etc.

Sway bar bushings could cause a steering vibration? I tried swapping the wheels and it did not seem to change.. My sway bar end links are definitely shot as they clunk over big bumps. I know my LCA bushings had a little itty bit of play with a pry bar too. These can make me feel a vibration? I thought it would be the moving parts..

Bad Lca bushings might. Normally they would make the steerling pull or push.Replacing the bushings will only help and also eliminate them as a cause for vibration.

Any other ideas?

I'd check steering rack bushings. You can move them pretty easily with a prybar even when brand new, that's normal, but they shouldn't be able to flop around freely. Also check for a broken engine mount (power brake with the hood open and watch engine for excessive play). The rear one under the trans you can inspect visually.

Motor mounts?

FWIW my 2022 Limited has done this subtly since new. Only when "on throttle" at lower speeds. If it take my foot off the throttle it goes away. Feels like something coming in contact when the engine is "torqued over" on the mounts. I went under the hood and under the truck and spent a few hours trying to figure out what it could be. No dice. Subtle, and not likely something that the service dept is going to have sympathy for.