thumping noise

2001 4wd 4runner , I developed a thumping knocking noise , it sounds like its coming from the front end so , maybe warped rotors so I put new rotors and pads on it ,no change noise is still there , about 6 months ago I put new front axles in it so I thought maybe one of those might be causing it , pulled the right one out drove it down the road noise is still there done the same with the left still there , tried it in 4wd drive still there no change . its strange because when you apply the brake it stops doing it , thats why i thought it was warped rotors anybody got any ideas ?? Im about ready to pull my hair out its driving me nuts PLEASE PLEASE ANY HELP

 

Thumping how?

Thumping that speeds up as you speed up?

One thump when you start going?

Stopping?

Help us help you.

Did you rotate the tires?

 

its making a thumping noise mostly when you are coasting about 25 to 35 mph it does speedup as you go faster. it sound like its coming from a wheel its rotational but not fast enough to be in the drive shaft and the tires are brand new. It stops when you apply the brake , thats why i thought it was a warped rotor

 

I also thought it might be a front drive axle , they are both new, but i took the right one out and drove it and the noise was still there , the left one had grease coming out of the boot so i exchanged that one for a new one but the noise is still there

 

When traveling and it's thumping, and you put the car in neutral and coast that way, what happens?

Weird that putting on the brakes makes it go away. If you had a warped rotor, you should feel it in the pedal.

I believe if it was a u-joint or drive shaft, it should thump really fast like you say.

Also, replacing/removing the front drive shafts, should make it change if it was there.

I would pull the front wheels and inspect and rotate them to the back just to see. Check to make sure the dirt shields are not hitting the rotors...but that won't be a thump either.

 

I"ve tried coasting in neutral and its still there and in 4wd and out of 4wd its still there and I removed the dust shields completely . I"ll try rotating the tires that"s the only thing I haven"t tried yet

 

well i rotated the tires , no change . The only other thing that i can think of is the bearings in the outer axle tubes , I guess i will check them for any up and down movement , but i have never heard a bearing make this kind of noise before its almost like a ka thump ka thump also there is no vibration at highway speeds smooth as silk

 

I got nothing.

 

yeah I "m thinking it"s in the front differential, I think I will pull both front axles and drive it to see if the noise goes away/ Other than that I don"t know where else to look

 

I vote on one of your wheel bearings being bad. I've had the same problem.

 

How, on god's green earth can a wheel bearing make a THUMPing sound?

 

One bad ball or roller!

 

I don't buy it. It will just grind. There isn't enough play with just one roller bad to thump

Edit:. I don't know, the more I think about it, I suppose. Man that bearing would have to be all kinds of ruined.

 

Steelman ChassiEars are great for finding those infuriating noises. You can hook to your two front wheel backings and compare the sounds while you drive. Or the rear of your transmission and differential to listen for noise from driveshaft.

 

I have wanted one of those noise finder thingies for a while. I need one of my cars to start rattling so I have an excuse to buy it.

 

Any update on the noise? I’m having the same issue. Mines a 1992

 

We have this issue on our 2000 Limited (240k miles) and I am thinking it is the torque convertor and/or flex plate. Our first 4runner. I have been wheeling since the 1970's.
We just got back from 12,000 feet elevation and major rocks over tincup pass.
The noise is crazy from 1-30 mph but stops at ~40 on tarmac.
If I hit the gas under 25 mph its horrendous sounding but stops at 40 or so.
We can feel the thump audibly wind-up every time we leave a stop sign.