Hey Guys,

I'm driving a 1992 4Runner, 4cyliner SR5. I've had a growing problem over the past few years (for the first 2 1/2 no one else could hear it but me) that has now escalated to a full fledged grinding noise. Let me get into some details:

It started as a hollow, metallic banging sound when I would hit potholes and rocks with my front left wheel. That slowly got louder until it would start to grind/vibrated for a second on and off. Now it is almost constant, but still is intermittent, during which quiet times there is no noticeable sound at all.

The wheel bearings, CV axle, front diff are all new or in decent condition. I've repacked the bearings in an attempt to quiet the noise, but nothing. All I can think of now are the brass bushings inside the steering knuckle that the CV rides on.

Any help would be greatly appreciated, and if there is any additional information I can provide I would be more than happy! I want to get this fixed and have my Toy back on the trails!!!

C

 

I should also note that there is a slight top-bottom play in the wheel, but it is not from the ball joints. It seems as if the wheel and disc assembly are moving along the spindle.

 

Isnt play in the wheel a bad wheel bearing? I know you said they're new, but maybe they were bad off the line.

Is it 4x4? manual or auto hubs? I have a grinding when my hub is engaged on a specific wheel.

 

It's an auto hub. I replaced the bearing about a year ago, and it didn't seem to change the noise at all when it hadn't reached it's horrible grinding stage (it came on suddenly and seemed to originate from the clanging noise I had been hearing previously). Also, when I repacked the bearings last week, I had an experienced guy look at them and he said they were ok.

 

Is it like a howling grinding noise?
Mine had this on the passengers side on the inner spindle bushing that the CV rides on.
And if i'm not mistaken, with the newer trucks you have the auto hubs so your CV's are always turning.
Maybe you should do what i did and re-pack your spindle..

 

I wouldn't describe it as howling, more as a hollowish, rattling-grind. The weird part is that it only begins after i hit a bump and is intermittent thereafter.

 

can you duplicate the noise by jacking that tire off the ground and spinning it?

don't rule out things like ball joins and such, cause in a worst case scenario of neglect and no greasing, they can start to rattle around and make some hellish noises too when they go bad

 

I can't get the truck to make the sound by raising the wheel and spinning it. The closest thing i can get to generating the same sound is by actually kicking the wheel. It generates one clang of (what might be) the noise. Keep in mind this could also be my imagination. The wheel spins freely.

Also, my brake rotor isn't in the best shape, and I can wiggle one of the brake pads with my hand. It could be the brake pads rattling, but wouldn't that stop when I apply the brakes (it doesn't). The noise seems to be minimally affected by the applying brakes, but does seem to increase in intensity when I slam them on and bring it to a grinding halt. The pads seem to be in fine condition, but the rotors aren't wearing evenly.

 

I think you need to take a fine-toothed-comb through the entire suspention and steering system; put your hand on EVERYTHING, from tie-rod ends, to shocks, to CV's, and check every mounting bushing like control arms, shock mounts, etc.

breaking a rear axle for instance is one thing, but having a steering or suspention component break free from the front of your truck at highway speeds can cause some SERIOUS issues... there's a lot going on at the front of a 4wd IFS truck with tie-rods and such; a lot of points of possible failure, any of which can cause major problems when they give out

 

Thanks Super Bleeder. I am pretty much in the process of doing that right now. It is not a pleasant sound and she's been off the road since it's gotten bad.

 

I agree with superbleeder on that one. Definitely do that

 

What did you torque the front wheel bearing adjuster nuts to? If there is movement in there either you didnt torque the bearings properly, or the bearings got so bad that they wore out and need to be replaced (aswell as the races in the rotor).

 

I torqued the bearings to the specs found in the Haines repair manual. I think the problem is the brass bushings inside the spindle on the steering knuckle. I've found a walk through on Yotatech for replacing them! I'll let you know how it goes. Thanks everyone.

 

I think, and someone will have to verify this, that the ADD rigs have needle bearings in there, not bushings, as the CV turns all the time on each side in the with the wheel. The needle bearings are rated for the higher RPM's and are lower drag.

This very well could be a dry or failing needle bearing in that location.

It is not that hard to remove the entire knuckle assembly from the A-arms. You have to tear down the "hub" and get the C-clip off the splined CV shaft. After that, just pop the ball joints, remove the brake caliper, and pop off the tie rod end. The entire knuckle/bearings/rotor assembly will then slide off the end of the CV and you can get into the back of the assembly.

Good luck,

Mike

Let us know what you find.

Mike

 

Thanks Mike! I've replaced what turned out to be badly damaged brass bushing on the inside of the steering knuckle (there are probably several different types on various models of 4runner). The sound is gone and the truck is rolling smoother than ever! Thanks for all your help guys.

 

where is this write up mertz? i need to do the same. thanks...

 

https://www.yotatech.com/forums/f128...4runner-76360/

I advise you to check your CV axle as well. I found that there was a gap between where the boot met the wheel hub, which was contributing to the noise or possibly causing the wear.

 

question i got my parts my outer bushing and inner needle bearing. but in this guide step 17 mentions a thrust bushing. whats the part number for that?
https://www.yotatech.com/forums/f128...4runner-76360/

 

yotalaz I think that should be the inner steering knuckle bushing.

I've had this same problem as well for a few weeks now. I'll be replacing as per Jim's instructions as well.

 

From what I'm reading you have the

Outer steering knuckle bushings (goes in the spindle ends)
should be part # 90381-30003, approx 27.73ea.
These are not listed in the authors list of replaced parts.

Inner steering knuckle bushings (goes in the knuckle end)
part # 90381-32001, appox 8.55ea.
these should be different from the stock ones that the write up shows being hammered out and replaced. The new ones are shorter in length to accommodate the needle bearing.
Thrust bushing and inner steering knuckle bushing being one an the same.

Bearing, Needle rolling
part # 90364-30011, approx 30.23ea.

And lastly the grease
part # 08887-80219 approx 12.89