Help! Thumping noise coming from the rear...rear-end? *VIDEO*

Justin00LS

Justin00LS

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This noise started a month ago and has progressively gotten louder. It is loudest around 20-30mph but it is nearly silent around 70-75mph. It is noticeably louder when i put a load on it or if I downshift and let the engine slow the car down. "Leaning" into sharp turns or going over bumps does not change the tone of the noise which leads me to believe it is the rear-end instead of drive axles.

Car has 150k miles and I drive spiritedly almost every day :D


Sorry for the crappy video..it was taken with my iphone. From 1:12-1:24 in the video I have my foot on the brake and gas to simulate a load.
YouTube- 1257924001.mov
 
sounds just like my rear wheel bearing did...jack it up and see if the wheels wobble..

oh and LOL at 34 miles till empty...:D
 
then again...maybe not..the wop wop wop..sounds like it, but then I hear what sounds like a ufo taking off....IDk what the hell that is.
 
tire tread separation

You may have a tire tread that is separating from the tire, look for unusual wear on the tread or a broken belt, the tire will look crooked.
 
Outkast said:
sounds just like my rear wheel bearing did...jack it up and see if the wheels wobble..

oh and LOL at 34 miles till empty...:D
Click to expand...

I plan on getting underneath the car in a few days to try to find out what is going on. But wouldn't the fact that the intensity of the noise depends on the load rule out the wheel bearings??
 
tireman said:
You may have a tire tread that is separating from the tire, look for unusual wear on the tread or a broken belt, the tire will look crooked.
Click to expand...

Just changed the wheels and tires and it has no effect on the noise :cool:
 
Justin00LS said:
I plan on getting underneath the car in a few days to try to find out what is going on. But wouldn't the fact that the intensity of the noise depends on the load rule out the wheel bearings??
Click to expand...

im not sure, but mine was louder at low speed than high. I could actually shake the tire by grabbing the top and moving in and out, with the car on the ground. The only thing that changed the sound, was if I swerved the car side to side at 50mph or so.
 
gotcha. Well swerving at 50mph or "leaning" into corners does not increase/decrease the noise.
 
The rear diff in my LS would make a slight howling noise at throttle tip in and on deceleration. Doesn't sound like a rear diff problem in that video to me.
 
NYC LS8 said:
The rear diff in my LS would make a slight howling noise at throttle tip in and on deceleration. Doesn't sound like a rear diff problem in that video to me.
Click to expand...

I get the howl on deceleration too.
 
Go under your car and reach in under the driveshaft, and push it up on its front portion, just before it disappears under the exhaust heat shield. If it moves up and down or side to side, you need a new driveshaft support bearing. I'm not saying that yours sounds like mine, but I think the phone is possibly a reason for that loss of clarity in the noise.

If it's not thumping (I heard some of that at only one stage) and it's the whining noise, then you're looking at potential pinion or spider gear bearing problems in the rear end.

If it is the shaft that is all wobbly, pick up a new bearing ($120 or so) and have them also sell you a new transmission extension housing seal while the driveshaft is off for the bearing replacement. The shaft wobbling kind of used up my rear seal of the transmission and a) it's leaking pretty nastily now, and, b) it's not even available through Ford for a manual transmission.

trust me, you don't want to have to go through this job in two stages, as getting the driveshaft off requires taking off the cat-back exhaust and heat shielding above it, in order to get the driveshaft off.
 
Mechanicboy said:
It sounds rubbery. Check you Guibos(flex disks), I believe our cars have two, one on each end of the drive-shaft.

Here's what they look like for BMWs.

http://www.turnermotorsport.com/html/subcategory_detail.asp?modelcode=Z3&subcat_id=127
Click to expand...



Thanks, I will definitely check this disc out. I have put two transmissions in the car and I feel confident that everything is tightened to spec.. I need to find time to get underneath the car and take a thorough look at everything. Another interesting thing about the noise is that it seems to get quieter after the car has been driven for a few miles and thoroughly warmed up.

At higher speeds, the noise turns into less of a "thump", and more of a whine. From ~70-90mph, it cannot be felt and it is not audible either. Here is another video.. YouTube- 1261520375.mov
 
milehighmikey said:
Go under your car and reach in under the driveshaft, and push it up on its front portion, just before it disappears under the exhaust heat shield. If it moves up and down or side to side, you need a new driveshaft support bearing. I'm not saying that yours sounds like mine, but I think the phone is possibly a reason for that loss of clarity in the noise.

If it's not thumping (I heard some of that at only one stage) and it's the whining noise, then you're looking at potential pinion or spider gear bearing problems in the rear end.

If it is the shaft that is all wobbly, pick up a new bearing ($120 or so) and have them also sell you a new transmission extension housing seal while the driveshaft is off for the bearing replacement. The shaft wobbling kind of used up my rear seal of the transmission and a) it's leaking pretty nastily now, and, b) it's not even available through Ford for a manual transmission.

trust me, you don't want to have to go through this job in two stages, as getting the driveshaft off requires taking off the cat-back exhaust and heat shielding above it, in order to get the driveshaft off.
Click to expand...

I'm told our cars have a U-Joint at the center also, If so make sure it's in good condition while you're in there.

On a different note. I don't think this is it but I had a bent rim once and it sounded somewhat similar to this. My best guess is still the flex disk, or something to do with the drive-line.
 
Well I just finished getting under the car with it in drive on the jack stands... Both rubber disks on either side of the drive shaft appear to be in good condition and the bolts are nice and tight. The cv joints have all rubber boots present and appear good. But if I put a screw driver up to the rear end and place the other end at my ear, it sounds and feels as if it is coming directly from the rear-end :(

Guess it is time to take the rear-end off and disassemble :eek:
 
milehighmikey said:
Go under your car and reach in under the driveshaft, and push it up on its front portion, just before it disappears under the exhaust heat shield. If it moves up and down or side to side, you need a new driveshaft support bearing. I'm not saying that yours sounds like mine, but I think the phone is possibly a reason for that loss of clarity in the noise.

If it's not thumping (I heard some of that at only one stage) and it's the whining noise, then you're looking at potential pinion or spider gear bearing problems in the rear end.

If it is the shaft that is all wobbly, pick up a new bearing ($120 or so) and have them also sell you a new transmission extension housing seal while the driveshaft is off for the bearing replacement. The shaft wobbling kind of used up my rear seal of the transmission and a) it's leaking pretty nastily now, and, b) it's not even available through Ford for a manual transmission.

trust me, you don't want to have to go through this job in two stages, as getting the driveshaft off requires taking off the cat-back exhaust and heat shielding above it, in order to get the driveshaft off.
Click to expand...

Did you do as he suggested? I think grabbing the driveshaft and checking play would be a good thing. Also with the screwdriver trick you can move the end of the screwdriver to different places to isolate the area of problem.
 
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