Repeating 'clunk clunk clunk' from rear during coasting, increases w/ speed

[jt1583]

so what would my life be without my car giving me shit all the time....

Just yesterday I heard a faint clunking from the back, that seems to have gotten worse quickly, or so I think.

I can hear it begin around 15mph, and from there it only gets faster as the car does. It's faint, heard best with the windows up and music down. It stops under load/accel, picking up immediately when I start coasting.

I jacked up the rear today and had a look around. Nothing obvious, unfortunately :squint: I shook the wheels around, and the suspension components, but nothing seemed loose.

I know the obvious points to sub/diff bushings, I'm running collars and can see the cracked bushing squeezing out like a fat chick in pumps. I've also read it could be the drive line bearing. What's the best way to go about checking these parts, or this whole fkin situation in general?

Thanks for any much needed advice/encouragement/motivational words

[mushmonster]

Differential pinion bearings would make a noise under certain loads as you stated depending on what bearing is going bad but, i believe that it would only make a humming noise unless its really bad.
Carrier bearings also make noise, and sometimes will change when going left to right . so i think maybe take a look at the drive shaft, center bushing, and u joints. unless its in your trans or axles.
You can set the rear or the car on jack stands, then put the car in gear, and use a stethoscope or long screwdriver to listen to the rear end or trans. best of luck!

[jt1583]

I jacked up the rear and tried moving all the suspension arms but didn't feel anything too loose. I also re-torqued all the bolts, including carrier bearing, subframe, suspension arms and diff bolts.

However when I grabbed the drive shaft on each side of the carrier bearing, and pushed it up / pulled it down, there was a good 1/4" of play at least. Is this normal?

My next idea is to tape a camera under there and video record it while I'm driving, I expect a repeating clunk like this to make some movement.

[jr_ss]

Check your u-joints... My guess is they are bad and need to be replaced.

[jt1583]

how to check them? The drive shaft U-joints, you mean?

[jr_ss]

Yes, driveshaft would be the only thing that has u-joints on your car...

Pull the driveshaft and inspect them... Excessive play in the u-joints can be found by moving it around. They should be tight without slop in them but still rotate smoothly.

[jt1583]

well technically the steering column has them as well =D

Not sure why i asked you to specify, I knew what you were talking about. I guess I need to remove it completely to do this, eh?

Do you guys think there's a chance this could be subframe bushing related, cause I've read these things are a lot of people's causes for noises in the back, but also from what I've read these are big 1 time clunks during accel/decel/cornering/weight shifting, not a repeating, increasing with speed noise.

[jr_ss]

well technically the steering column has them as well =D

Not sure why i asked you to specify, I knew what you were talking about. I guess I need to remove it completely to do this, eh?

Do you guys think there's a chance this could be subframe bushing related, cause I've read these things are a lot of people's causes for noises in the back, but also from what I've read these are big 1 time clunks during accel/decel/cornering/weight shifting, not a repeating, increasing with speed noise.

Subframe clunk is when you're accelerating. Any weight shift really in the rear could make the subframe speak out. It should not speed up when you're driving down the road. What you described is a rotating noise. Increases when you accelerate, and decreases upon decel. Driveshaft is what I would look at first.

Another thing it may be is your halfshafts, the CV joints in the inner/outer ends could be bad. Look for cracked boots, leaking oil/grease around those areas. CV joints are known to make racket if bad.

[nismosx]

is your car a s14? mine was making the same noise i looked at my trunk one day and one side was higher than another it wasnt sitting properly to the weather seal causing the noise so i loosing the striker on the body and moved it down and trunk sits flush to both 1/4 panels
hope this is the problem it was a easy fix for me

[BDMs14]

driveshaft center support bearing is gone.

[jt1583]

I like your confidence BDM, I tried to feel the center tunnel as I was driving today for carrier bearing vibration and may have detected something.

Although, intermittently I am hearing what can only be described as a high pitched squirrel, also at the same frequency of the thumping, but it comes and goes. While the thumping noise sounds like it could be in the center (driveshaft) this noise sounds like its coming from the rear driver side. I'll get a friend to drive it as I walk next to it (sometimes it happens at low speed) to further narrow it down.

That makes me think it could be the CV axle. I'll probably grab 2 and replace them in the back, as it could use them anyway. Any reason I shouldn't buy Pep Boys CVs? Also, hows one go about replacing the carrier bearing? I read some machine shop pressing is involved =/

[jr_ss]

Just buy a one piece driveshaft and throw the center carrier bearing in the trash...

[jt1583]

im gonna get a golden toilet to crap in too while im at it =D