4Runner has been making funny noises for about a year. Possible sources of this noise are:
1. Tires imbalanced and wear unevenly. This mostly happens to people who don’t rotate their tires. Rather, it happens when the tires are not balanced or you have alignment problems, but tire rotation helps mitigate the uneven wear by spreading it around all four tires. I rotate mine fanatically with every oil change. I do have some road noise from this, but I don’t think it is the primary culprit for the worst noise.
2. Front wheel bearings.
3. CV axles. Like front wheel drive cars, this 4WD SUV has 2 of these, in addition to also having two drive shafts and a rear differential.
4. U joints. I thought this was the culprit at first so I have replaced all of mine in the past year and the noise got worse. (4WD SUV has 4 of these).
The noise gets worse when I accelerate and not when I coast so eliminate 1 and 2 since those noises would increase with RPMs and not load. Take off the tire. Remove the brake line from the anchor point to give more slack.
Remove the caliper and hang it up so it doesn’t damage the brake lines or ABS sensor wire.
Remove the castle nut that holds on the steering rod. Tap it out or use a puller to separate it. Be ready to use new cotter pins to reassemble it.
Remove the center hub dust cap using a chisel or old screwdriver. This exposes the hub nut and another cotter pin.
The hub nut is on tight. To remove it I put the tire back on and lowered the car back onto the ground. Then use a big breaker bar with an extended handle. This is where you find the difference between cheap Chinese tools from Harbor Freight and better Chinese tools from Lowe’s or Sears.
Then remove two bolts from the underside of the hub, not the castle nut. And give the center spline a few taps with your hammer. It should slip right out.
And now that it’s out, that bearing feels a little rough too. So I’m going to go ahead and replace that as long as I already have this all apart. Update: everything is back together and running fine. I skipped the new bearing and will be taking the one I bought back. I need a press to install it and I don’t have one. So I need to buy the hub assembly with the bearing already pressed in. I can’t tell if all the noise is fixed because it isn’t worth going all the way to the interstate for a test drive. My post mortem exam of the old CV showed nothing remarkable other than a torn boot.
Learning points. Don’t use a metal hammer on the axle as this can damage the threads. If you don’t have a slide hammer, you can pry the CV loose from the transaxle with an angled prybar. Put a drip pan under the car. The transaxle will leak when you remove the CV. Some of it will leak into your skid plate so remove that too for easy cleanup.