What is this noise?

[Old Henry]

Here's the noise that started last week on our Nevadaho Road Trip. What do you think it is? (12 second video)

https://www.youtube.com/watch?v=jWo9x...ature=youtu.be

[PeteVS]

Have you used a stethoscope? Or, a broom handle? (One end on the car where you think the noise is coming from and hold your ear to the SIDE of the broom handle.)

[Old Henry]

Originally Posted by PeteVS

Have you used a stethoscope? Or, a broom handle? (One end on the car where you think the noise is coming from and hold your ear to the SIDE of the broom handle.)

I haven't done that yet and maybe I will. I don't know how I would record that for others to hear. I don't hear anything when the car is in gear running. As in the video, I can only hear the noise when the wheels are turning but not connected to the engine. As far as location and source of the noise, it is definitely in the rear end - more likely in the differential than the axle. Any ideas?

[f1builder]

broken axle spline?

[Ralph Moore]

Sounds like ring and pinion, if I understand what you did was shut the engine off and push in the clutch. Do you only hear this while decelerating going down the road?

[Mart]

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Sounds serious.
I can't say what it is, but I think I can say this.

It appears to be at wheel speed. If you watch the torque tube, you can see where the light is shining through the left wheel, and and you can see the rotation of the wheel in the light. The noise seems to match the speed of the light on the torque tube.

This would tend to rule out anything associated with the torque tube or driveshaft, for example the noise when the pin comes adrift and rubs on the torque tube, something in the pinion bearing or the driveshaft intermediate or front bearing or the UJ or trans bearings.

That's quite a few things ruled out.

So what's left.

Wheel bearings, ring gear tooth damage. Ring gear bolt backed out?? (sorta guessing here) Diff side bearings

I'd say a strip down is inevitable.

If you didn't want to pull the whole rearend you could remove the left shackle and just remove the left axle bell, and the ring gear and shafts can all be removed.

I can't think what it could be that would be fixable without some sort of a teardown.

Have you drained the oil and checked for metallic particles in the oil?

Have you held the right wheel and turned the left and held the left and turned the right?

Or repeat the test like in the video but with each wheel locked in turn.

Might not show anything, but you never know, it might show something.

Can't help thinking, though, no matter what you find, a stripdown will be needed.

Mart.

[Mart]

I just had another look - if the light is shining through the 4 windows in the wheel, it is approximating driveshaft revs, so it could indeed be driveshaft related.

Still pointing towards a teardown, though, I think.

Mart.

[Alaska Jim]

sounds like a chipped tooth on either the ring or pinion gear. had a chipped tooth on a pinion gear once that sounded similar. I still to this day don't know how that pinon tooth got chipped.-----Jim

[Old Henry]

Originally Posted by Ralph Moore

Sounds like ring and pinion, if I understand what you did was shut the engine off and push in the clutch. Do you only hear this while decelerating going down the road?

There is some sound decelerating but mostly with clutch in or in neutral.

[Old Henry]

Originally Posted by Mart

Sounds serious.
I can't say what it is, but I think I can say this.

It appears to be at wheel speed. If you watch the torque tube, you can see where the light is shining through the left wheel, and and you can see the rotation of the wheel in the light. The noise seems to match the speed of the light on the torque tube.Can't help thinking, though, no matter what you find, a stripdown will be needed.

Mart.

That is extremely obsevant. However, the flash on the torque tube is through the gaps in the wheel which is four flashes per turn of the wheel. So, that's more the drive shaft speed incriminating something at the back end of the drive shaft or pinion part of the differential. (Oops. Just saw your next post that concluded the same.)

No question - I'm going to have to take something apart. Just trying to narrow down where to start - back end of torque tube or differential. Stethoscope is probably next. (I've usually used a long screw driver but I like the idea of the real thing.)



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[Henry/Kokomo]

Sounds can really travel and fool you. I agree it's at driveshaft speed. Might get lucky and it be the U-joint (hope so). Personally, I can't see any way to prevent some serious disassembly.

[Old Henry]

Couldn't wait till tomorrow to buy a stethoscope. Got my long screwdriver out and used as a stethoscope. Sound is definitely inside of the differential. From the sound and speed and frequency of it I'm thinking it's something to do with the pinion gear. It's not regular enough to be a broken tooth. It's more random like something else broken loose. I guess it's time to tear it apart and see. May try Mart's idea of starting with just removing the left bell and see what I can see and maybe replace without removing the entire axle. Thanks for that idea. I'm still open to any others as well.

[Don]

Think I would remove the brake drums to start with and try the noise run again

[41ford1]

With all you've done and your posted findings. I'm thinking a pinion bearing failed. Noisy running with no or low load and gets quieter loaded leads me to believe that. At any rate it's going to be a project. I'm interested in what you find.

[Old Henry]

Won't even start on it until after December 10th when we have our big family Christmas party in The G'Raj Mahal (http://www.garagejournal.com/forum/s...d.php?t=175104). Can't do that if Old Henry is stuck in there without any back wheels or axle. So, I'll just keep driving it until then - but no further than I'd want to tow him home if he really broke down.
Wish me luck.

[Old Henry]

Originally Posted by 41ford1

With all you've done and your posted findings. I'm thinking a pinion bearing failed. . . . I'm interested in what you find.

That's what I'm thinking too. Sure rather it be that than the pinion or ring gears. That pair costs $450.00 new.

[Old Henry]

Originally Posted by 41ford1

. . . it's going to be a project.

Fortunately, I have Chuck up the street that just rebuilt his rear end on his '47 after blowing it out on our Death Valley trip last February. (https://www.fordbarn.com/forum/showthread.php?t=62705) I'll be pickin' his brain the whole way.

[BILL WZOREK]

Old Henry:

Just out of curiosity have you pulled the plug and check the grease level,
I know it is like closing the "BARN" door after the horse is out,but do I remember you taking your car to a Professional lube & oil change center.
Not Ha Ha funny but still funny that 2 of you from the same area have had some type of rearend problem.

[PeteVS]

I saw somewhere that a problem with the Ford rears was that the pin in the driveshaft coupling would break and rattle around. The recommended fix was to drill a hole in the torque tube at a certain location, fish out the offending pin halves and put a pipe plug in the hole.

[jimTN]

Pull the plugs on the center housing, look for metal in the grease, shine a light in there and look around. Sort of sounds like a loose bolt that has run out and rubbing the housing to me.