I have a 2002 4Runner with an auto 3.4 and a bearing whine that is getting increasingly worse. It sounds like I'm running aggressive MT's when in actuality I'm not.

It whines only in low, 2nd and drive in 2wd. The noise starts around 10 mph and follows through all speeds upward to about 70 mph when the road noise becomes louder than the whine itself. I'm certain it isn't the torque converter as it doesn't do it in neutral on when there is a load in 2wd.

It does not whine in 4wd Hi not sure about low but figured it was irrelevant. Does not make noise in neutral. Doesn't seem to make the noise in reverse but have never gotten up to speed enough to tell

I though perhaps it was the U-joint somewhere along the line but I remember those being more clunky that whining.

suggestions would be appreciated.


A

 

check to be sure the driveshafts are all lubed up. Then the U joints. And I believe something called the slip yoke...

I'm no mechanic and not pretending to be-just repeating what I have read previously regarding the symptoms you are describing.

I'm also thinking it could potentially be the beginning of an axle bearing going bad (I am encountering that as well)- but start with that other stuff first.

 

Driveshaft with both slip yoke and u joints all greased and ready.

Noise has gotten louder which will ultimately help the cause of determining where it is coming from.

A

 

Maybe the rear diff. You got new gears a while back, yeah?

 

hi. have you changed the gear oil in the rear diff?

 

Yes and yes, the rear diff was re-re-geared (4.56 to 4.88) about 40k ago and oil changed about 1100 miles ago when I first noticed this noise. Likely replace u-joints tomorrow as a cheap way to rule them out. I hope it isn't the pinion bearing but if it is it is, I have a solid spacer in there so no chance I buggered it up offroad. Can't remember the exact make up of the tru trac LSD but did notice some foaminess to the oil when I changed it last.

A


Aaron

 

is there a carrier bearing on this 4runner? also maybe a wornout wheel bearing?

 

Well not being able to fully determine what the heck the noise was I Pulled the drive shaft and wiggled this and that and found some play in the double cardan, which if I remember correctly there should be none. While throwing money at problems until they go away isn't the best way I feel at least I'm throwing it at the correct end of the vehicle.

I'm going through what other have when trying to find the proper u-joints for the double cardan itself. These are virtually impossible to find unless your willing to pay $86ea from good ol Toyota.

I will likely have to take it to a local driveline shop and have them do what they can which if they find something that fits it will be $160 and if they have to bore the cardan to get something to fit it will be $460.

It would be funny if this ended up being a wheel bearing, I put the rear on jack stands and a floor jack got in, cranked it, and put it in gear. I had my dad listen and watch to determine where or what was whining. With no load in the air something sounded like it was getting in a fight under there so we opted to pull the shaft.

A

 

 

While we'd be glad to help you need to post in the correct forum.... this is for 95.5-2004 Tacomas & 96-2002 4Runners 4th gen pickups and 3rd gen 4Runners.