lululalalu

My 88 4Runner 22re 5-speed is making what sounds like a cross between a bearing going out and tire noise.

It increases in pitch with speed and does not go away coasting in neutral.

Had my buddy drive by me a few times. It gets lost in the tire, engine, etc. other noises, but you can hear it and cannot pinpoint it.

Mechanic did the passenger front bearing and some tie rod ends. The noise is unchanged.

Suggestions?

How could I test the driveshaft bearings and u joints in my driveway? Would those even make that kind of noise?

Jimkola

It's a process of elimination. And like anything, do one thing at a time and test drive.
On a 4wd, tires were a common issue. Especially when they deviated much from stock(off road, mud, over size etc). Some of those tread designs wore very poorly, especially regarding heel-toe wear and cupping. Cupping will have a vibrational shake associated with it, but heel-toe often doesn't. And both can get loud. We simply got a truck from our inventory and swapped tires and drove the customer's truck with our tires. If that remedied the noise we usually had to take the customer on the drive because they rarely believed that their tires were THAT loud. A picture of your tires would be helpful.

A driveshaft with failing u-joints will have a vibration associated with it. Especially on take off.
Transmission bearings going bad is common. Is it quieter in 4th gear, as opposed to 3rd and 5th?
Diff bearings usually go bad at the pinion bearings first. They handle the brunt of the hard work. If they're failing you might see oil leaking at the seal, along with being able to move the flange where the driveshaft connects up and down a bit.

If you want to keep this thread alive keep posting up what you find. and pictures of you rig would help the thought process.

Blueman

Long ago I was convinced I heard right-front bearing noise on my truck, sometime during it's first 50,000 miles. Turns out it was just tire noise.

Here's a test you can do for tires: Compare the noise at high and low inflation levels. If it changes, you've found your root cause.

As to driveshafts (and propshafts), crawl under the truck and see if you have play in the joints. Also, grab the u-joint and make sure the nearby bearing is tight -- the shaft doesn't move left/right/up/down when you pull/push on it.

2ToyGuy

Failing propeller, or drive, shafts, in my experience, usually give themselves away with a "clunk" when you first start moving. Usually in reverse, first, then in the forward gears. When you get under there, and try to move the drive shaft, the u-joints that are going bad are pretty obvious. They allow a lot of movement they shouldn't.
My pickup is on it's 4th set of u-joints, so far. About 1 every 100,000 miles, roughly. My 4Runners still have their factory original u-joints, double cardan joints, etc, but I lube them at least twice a year. Spring and fall.

lululalalu

Thank you all for your suggestions. I will investigate over the holiday and post what I find.

Perhaps the sound was there all along and I simply did not notice it, but one moment I was driving and there was no noise, then suddenly it started and I turned the radio down to investigate.

Also, the rear tires (regular Goodyear Wranglers, not large off road tires) are cupped (I run 40 psi for no defensible reason if that contributed to the cupping).

But as stated above, the sound was not present (unless I missed it), and I thought I heard it begin for the first time all of a sudden.

The rear cupped tires have been rotated to the front, and the seemingly fine front tires were moved to the rear. No change in noise, or where it "feels" like it is coming from (passenger front).

Blueman suggested a tire pressure change to test the tire noise angle. How low should I go on psi for the test drive?

I assume tire noise should change due to the psi change. But if there is something else causing the noise, it should remain relatively unchanged (related to rolling speed weather in gear or coasting in neutral as it is now).

Thanks in advance,

2ToyGuy

There should be a sticker on the driver's door jamb with the recommended tire pressures, front an back. Start there. I use 32 front, 34 rear. Pretty close to the recommended pressures. Mine wear very evenly.
From the Goodyear website:Tire cupping is typically a symptom of different vehicle suspension issues. If your vehicle’s suspension isn’t working properly – whether there are worn or damaged parts, a misalignment, or a combination thereof – your tire may struggle to maintain the intended force against the road surface and lead to this tire condition.

Typical suspension issues which may lead to cupping on the tire include but are not limited to:

• Misaligned Tires: If the tires have too much misalignment in the wheels compared with the factory alignment specifications, the motion of the vehicle can cause uneven strain on the tire.
• Worn Suspension and Shocks/Struts: Your shocks/struts and the springs work together to absorb road imperfections by controlling how each wheel reacts to a bump. If this system isn’t working properly, that wheel/tire of the vehicle can bounce more than was designed and can be a cause of the cupping.
• Unbalanced Tires or Bent Wheels: If your tire is out of balance or a wheel is bent, the centrifugal forces involved in spinning an unbalanced wheel can bounce the tire enough to lead to cupping, over time.

Hope this is some help. Whatever's causing the trouble, I would get it fixed ASAP. After all, why waste a perfectly good set of tires?

Good luck, and let us know how things go for you!
Pat♂

Jimkola

Yes. Many things may cause cupping.
And if you go to the tire shop that sold you tires I can pretty much guarantee they’ll try all that before considering the possibility that those tires, on your truck, just didn’t work great. And no, 40 psi probably didn’t help the situation.

Tire Balance I can't imagine a vehicle with tire balance so bad that it could cause cupping, but not shake.
Alignment Improper alignment almost always hammers the edges of the tire, especially the inner. So cupping, without edge wear, would lead me in a different direction. And aligning the back would be a neat trick.
Shocks this has some merit, except most tire shops base shock replacement on miles, not actual performance. And odds are, the shocks they recommend are stiffer , which would aggravate the condition if you have a empty bed most of the time. I could see a loaded truck benefitting from new shocks.
If you google tire cupping you'll see a pretty consistent agreement on what it is among tire manufacturers and installers. And as far as possible mechanical causes everyone seems to include poor quality tires except Goodyear. Among name brand tires, from my experience Goodyear seemed the most prone to this condition.

Back in the early 1990’s we had a rash of cupping on fairly new Corolla wagons with Goodyear tires. I got on the phone with a Goodyear tech rep who was pretty matter-of-fact. He simply said you’re dealing with a light vehicle, with stiff suspension, and the Goodyear tire installed on the new vehicle was a hard tire(long wearing/ better mpg), and not pricey. The combination of all those factors played right into cupping. Cupping is when the vehicle sorta hops a bit. Not enough to lose contact with the ground, but enough to weight/unweight the tire while rotating so the wear becomes uneven.
The backend of any truck without a load is light, but a Toyota is ridiculously light. Then take into account any suspension mods or lifts that almost always stiffen the suspension you run a high risk of cupping unless you buy some pretty quality tires. That said, even with great tires you have to be pretty diligent on rotation. The tires promising high mileage tend to be pretty hard, so be watchful of the wear.
Once cupping is bad enough to notice while driving its pretty hard to undo. Rotating may help, but for the most part those tires are a lost cause.

Blueman

So, the goal is to isolate if the tires are the source of the noise, and I would expect changing the pressure to change the noise as it'll change how the tire contacts the road. I think you can safely (others may have thoughts on this) go down to 20PSI (or lower) for the low end, and then go up to the max rated pressure on the tire's sidewall for the high-end. If the noise you're hunting doesn't change, then I'd start leaning away from tires being the source.


Side story: I had a strange vibration in my truck, and had a hard time isolating it. My tires (Bridgestone) were old and worn, and I'd wondered if they were an issue. I raised up each tire and spun them by hand.. Looking from the side, I could see the tread bump outward on one tire at a certain clocking. Looking at the face of the tread, I could see the tread jump sideways at that spot. Likely it'd had some kind of internal belt failure. New tires came soon afterward! Cooper AT3.

emsvitil

To see if it's the transmission, remove the shift boots from around the shifters so you can see the top of the transmission and transfer.

If the noise is from them, you can tell........................

SomedayJ

I had a similar noise, it went away when I tightened the front lug-nuts from the noisy side. The problem was that alloy rim had deformed holes because the PO used the wrong lug-nuts with it.