stangman39

Hi all,
I have a 2000 Sr5 2WD 4Runner. Got it with 82K on it and now have 124K. It really has been great.
I do a bit of highway driving twice a week to check on properties I am fixing up. When driving on the highway tonight...above 60mph, I noticed a humming and felt a slight vibration under my left foot...coming from the front driver wheel area. I thought at first it was the stretch of road I was driving on...almost like the sound when you get into a certain groove on the highway. Well, after awhile I noticed the huumm and vibration was happening every time I left off the gas and let the 4Runner decellerate.
Have never experienced this before and it only seems to be coming from the front drive wheel area. Didn't notice it on the local non-highway roads.

My tires are probably gonna need to be replaced in about 5K miles (they are the ones that came with the 4Runner when I got it...so they have at least 42K on them).

Any thoughts? If I knew for sure nothing was really wrong or I wasn't going any harm I "could" live with this but when you know your car really well and drive it every day...most of us can tell when something is taking place that didn't use to!

Thanks,
Mike

CdTriX

is it something like this?

i'm having the same problem..

highway speeds... let go of the gas.. and it vibrates.

link here

http://www.mediafire.com/?mfirfiz9gdz

stangman39

Well...my fix might sound kinda silly....but my tire pressure in my driver side front tire was low...down to about 25psi...so I bumped it up to about 42 and it seemed to solve the problem!

Now I've got some intermittant rattle noise coming from around the front passenger side footwell area....but that isn't bothering me as much since it happens when it is colder out maybe once a week!

Mike

mjwalfredo

Whoa, 42 lbs is quite a bit... You're going to be in for a harsh ride if you run all your tires that high...

stangman39

I think my tires say max psi is 44....
I usually run all of mine up around 40.
Maybe it is a harsh ride...but it is all I've been used to since I for the 4Runner.
What are you running yours at? I've always thought run the psi close to max as it will help with overall mpg.

Mike

mkgarrison5

i have had the same sort of issue and sure enough my front left tire was down to 20-25psi.. i inflated to 33-35psi and could tell a difference... since you have a 2 wheel drive that nixes any kind of u-joint issue or anything..

3w41d

check your wheel bearings. my dads tacoma was doing this and he filled up one tire and it went away but the bearing completely destroyed itself and almost caused the wheel to come off

mkgarrison5

what are the symptoms of a bad bearing? i have never had on to go bad before in any of my vehicles and this includes my cheap jeeps

mjwalfredo

40 is still pretty high. If the ride doesn't bother you then go for it. Common sense says that having it higher is better for gas mileage.

I had bad rear wheel bearings from leaky rear axle seals. The oil washed all the grease out of them. To me, the symptoms felt like a grinding/vibration that was most pronounced at 30-40mph and 70 mph. The weird thing was that it felt like the vibrations were coming from the front wheel well.

I even replace my whole front 3rd member thinking there was something wrong with the diff or gears. That didn't help one bit but as soon as I had new rear bearings pressed on, the vibrations were completely gone.

BajaRunner

Your deaccelerating issue sounds like unlubed zerk fittings on the drive shaft. It also could be you need to get your tires rotated AND balanced. Tire pressure is huge, and obviously, if you are braking then your rotors need to be turned.

Most likely it is not a front wheel bearing. You'll hear it, and they are sealed units from Toyota which are made to last a while.

I would say that your problem is probably your tires though. They are old and this will happen.

turboale

Could check the trans mounts too...

mjwalfredo

Good advice but I think it would be even better if people explained a little bit more when giving advice like this.

Like, what are you checking for? Really obvious damage or rotten rubber?
Should you stick a jack under the tranny and jack it up a little bit to check teh condition of the rubber. Are there broken bolts, etc?

I think if I read this and went to check, I would just look for a loose or missing bolt or missing rubber. Could less obvious problems with the mount manifest themselves as vibrations?