getitdone

i have recently purchased an 85 4runner(sweet!) any way i just drove it down to austin from dallas(200 miles) and it is making a loud whining noise at high speed. the noise gets higher and louder according to road speed and it sounds kinda like a jet engine whine. the truck has about 160 thousand miles and is in very nice condition, seems to be very sell kept/maintianed. i was crusin down the highway with the doors off(very cool!) and popped my head sort of under the truck to hear the noise and it sounded like it was comming from the rear diff, sounds like gears. i had a lube place change the diff fluids and still no change in noise. somebody please comment about what they think it could be.

backfrog

yeah i just bought a 87 4runner and i've just noticed it when i took it on the highway. i would like to know too.

I hear some noise when i'm decelerating too.

PirateFins

I have a 92 with the same whine and haven't been able to fix it with different fluid changes and I don't think it is major.

TACOMANATOR

iIts just the gears whining. Its normal-my 2000 does it and my 99 Rodeo also did it. They both had fresh synthetic and low miles. No worries.

ROMAD

No comment on the noise but I think you are freaking nuts if you did that while driving!!!

Sounds like its normal noise though so hopefully its all ok.

Flamedx4

Well.... I drove an 85 for 172k and it didn't whine like that, either when stock or with 4:88s. What you're describing sounds to me more like transmission bearings. Test it this way, at say 30 - 35mph, put it in 3rd and get on the gas fairly strongly, listen for the noise. Then do 4th gear. In 4th, you would notice virtually no noise, even if its the mainshaft output bearing, because 4th is straight thru and there is no side loading. The noise sounds kinda like: Imagine if you put a couple of BBs in an empty coffee can and swirl it around. It makes a metallic sound that's not quite grinding and not very loud but plainly evident. As the trans bearings get worse the noise will grow. You'll mostly hear it in 3rd and 5th, 4th is usually nearly silent. When it begins to get noticeable louder, the transmission is going and will not last long. Rebuild it before it breaks and its cheaper.

Or it could be axle gears, u-joints or who knows... ;-)

PirateFins

I have over 200k now and I hear it in any gear (even 4th). It's deffinetly a whine, not metallic. It has been doing it since 120K. Not saying that it's right just That it has become norm.

Flamedx4

I had an annoying whine from the passenger seat for a few years...

getitdone

very funny flammed... i will try the 4th gear thing tomorrow. thanks for the input

ROMAD

Stoopid thought just occurred to me - do any of you guys have spit drive shafts and drive shaft bearings?

I had a 4x2 Nissan with a split shaft and long before the bearing failed it made all kinds of noises I was aware of but couldn't figure out...

Never had U joint fail but maybe they could make some sounds if failing?? I dunno on that one I admit its just a SWAG

Scooter22

My 92 made a sound like that one time. It was after about 10hrs of highway driving(long road trip), after I allowed it to cool it went away. Like ROMAD suggested check your U joints and/or Center Bearing(if you have a split shaft). On my truck the U joints are greasable so it could be just a lack of some much needed grease.

Tacoma Dude

I don't think you need to worry about it being your rear diff.
I have some minor rear diff issues and the sound isn't a whine, it sounds a lot more like white noise or static from a radio - that incessant *kshhhhhhhhhhhhhh* sound.

getitdone

i tried out the sound in 4th and it is just as loud as the rest of the gears. i wouldnt be so worried if it didnt happen right after the 200 mile trip. now that it has started it happens all the time, cold or warm, for how ever long i drive it. any thoughts?

etro

My 93' 4 runner is making the same whining noise in all gears. Please advice!