'98 4Runner driveline/running noise -

[SteveH]

My '98 4Runner (5 speed, 118K miles, stock height) developed what I call a 'bad wheel bearing sound' after a 4000 mile vacation trip.

At speeds of 30 and up - most noticable between 30 and 40, it makes a rhythmic whirring sound that sounds mostly like a bad wheel bearing. I thought it was the RF wheel bearing and replaced that, and it make no difference. All fluid levels are full, CVs are fine, and the noise is unaffected by braking, accelerating, or use of 4WD, or going into neutral/clutch in. I rotated the tires and checked pressure, and the sound didn't change. The sound seems to come from all over the truck - not starting in any given place.

Any ideas?

Thanks,

Steve

 

[KliersLC]

Could be the L/F...

Not that I recommend this, but you "could" do the jack it up on four stands and set the cruise and listen approach.

Also maybe a small exhaust leak??

dunno fer sure tho,
Dan

 

[SteveH]

I agree- could be the LF. The RF was worn a bit, but not badly. I just checked the exhaust and it's not a leak or heat shield issue. This one is a stumper for me, just because I've checked so much. I may have a buddy put it on a lift and see if it will do it with the tires in the air and under some other conditions.

Thanks! - Steve

 

[Isotel]

My Runner had a Right Wheel Bearing go out on it.. but it didint make much of a rythmic sound.. Driveshaft?? Balancing of tires.. Could be alot of things..

Sorry im not much help..

BTW Feel Free to stop by The colorado Springs Section on Mud.. and introduce yourself..

the next meeting is the 19th.. https://forum.ih8mud.com/forumdisplay.php?f=85

 

[SteveH]

I had my Toyota garage buddy put it on a lift - the LR Wheel bearing is shot. It was much louder running in the air on the lift at 40 mph, since the wheel was bearing no weight.

Thanks for your suggestions. The funny part is that the sound was non-directional - it sounded more or less the same all around the truck - not apparently coming from one corner or another. Fortunately, I caught it before the axle oil leaked onto the brake shoes. $160+-ish in parts - two bearing collars, ABS ring, bearing, and seal.

Steve

 

[KliersLC]

I had my Toyota garage buddy put it on a lift - the LR Wheel bearing is shot. It was much louder running in the air on the lift at 40 mph, since the wheel was bearing no weight.

Steve

Where exactly is the LR






Glad you got it figured out..

Dan

 

[SteveH]

Sorry - Left Rear (LR) wheel bearing. And it's a BALL bearing. Talk about a lame design. I'm amazed it lasted this long. This should have been a roller bearing or just about ANY design other than a ball bearing.

I'm reassured to see that the entire weight of the back half of my truck is borne by two contact areas the size of a pinhead. And, the bearing is not lubed by the rear axle oil - it's a sealed bearing in a cavity, so the only lube it ever gets is whatever Toyota put in the bearing at the factory.

To top it off, the mechanic tells me that Toyota redesigned the axle oil seal and 'they've had some leakers' so to keep an eye on it.

I'm about to put a GM 10 bolt axle from an S-10 Blazer under this truck for added reliability and design quality .

 

[Isotel]

I'm about to put a GM 10 bolt axle from an S-10 Blazer under this truck for added reliability and design quality .

Seriously.. Thats crazy bro.. The Axles under my truck came from a Junkyard 1980 Pickup(same basic design as your 98), now they are in my cruiser, and the Bearings where in great shape after 25 years of use, and 200k Plus miles..

gm 10 bolt is an ok axle, but the toy is just as strong..

 

[SteveH]

I really wouldn't consider a 10 bolt axle - but after 5 Land Cruisers, all with considerably more miles on them and no axle problems, this design seems pretty chintzy. I'll have my parts guy pull a mid-80s rear axle bearing (if he's got one) and compare it to this one. I'd like to know if the bearings have gottem smaller and lighter over the years in 4Runners.

 

[SteveH]

Another data point - I had the dealer pull a rear wheel bearing for an '89 4Runner and it's a roller bearing. The rear wheel bearing for a '98 4Runner is a ball bearing. Maybe this is why the old 4Runner rear axles seemed to go forever...

So, either for gas mileage or cost reasons, or both, Toyota has put an inferior (from a true design standpoint) component in their newer rear axles.

Steve

 

[2ndGenToyotaFan]

That sucks...... Glad I have an 89!!!