Grinding Noise Diagnosis—Please Offer Ideas (Video)

Not sure what’s going on here, but I suspect a bad left rear bearing. We replaced all wheel bearings a couple years ago with the ones that NEV sells (which I’ve come to learn here are cheaply made, but overpriced ones).

In the video you’ll notice that the noise starts and then stops for a bit, then resumes.

The noise occurs when accelerating or just moving along. Earlier this year I replaced the drum shoes in the rears, bled the brakes, etc, and also replaced the drive shafts with the NEV ones. All was great until today.

I’ve checked all of the rear control arm bushing bolts, but they’re all tight. Nothing seems amiss.

Jacking up the rear and moving the wheels along forward and back doesn’t produce any strange “bad bearing” sound. I thought maybe something in the gearbox was messed up. There’s no “jiggle” in the wheel, either.

The noise sounds as horrid as it does in the video. When we replaced the bearings before, they were making some noise but nothing like this.

Any ideas?

Thanks!

That doesn’t should like a wheel bearing or suspension noise.

When you jacked it up did you put it in drive and use the motor to spin the wheel or where you just turning it by hand?

You can use a piece of hose around 1" diameter and put one end to your ear and move the other end around until the noise is the loudest.

Since you believe the noise is coming from the LR I would pull that drum off and take a look.

Thank you for replying. I only turned the wheels by hand and didn’t use the motor to drive them.

Your thought about the drum sounds like the right move the more I think about it. I’m imagining a loose wheel cylinder bolt bouncing around in there, getting caught against the drum and making that noise.

Either way, I’ll report back with what I find.

Thanks,

John

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I don’t know how thinks are put together or what parts Ford used, but I do agree with @David_Illingworth
that isn’t a failed bearing, or at least nothing like any I’ve ever heard. It might be something caused by one though. To me, it sounds more like something scraping. Maybe some errant metal chips will give it’s position away.

Have the wheels and drum covers off. No foreign materials present.

Both rear sides are raised up. Is it normal in this circumstance for only the left rear wheel to move when depressing the accelerator? The right rear shaft isn’t spinning when depressing the accelerator. I’m not sure what kind of diff these Things have?

It’s all just gears. I seriously doubt there are any fancy locking clutches.

Can you manually turn the passenger side at all?
It should turn as easy as the driver side.

It’s normal for only one side to spin. If you put the left side on the ground than the right side will spin.

Yeah, seems to be an open diff. Both wheels spin fine when off the ground.

I traded texts with someone who performed work for me on the Think before, and he thought it could be a wheel bearing or even a motor bearing. (I have a D&D blue.)

I’m going to have my wife drive around with me hanging off trying to pinpoint where the noise is coming from.

Still dealing with this issue. I replaced wheel bearings with Timkens. Had to replace rear brakes due to a blown cylinder. Replaced differential gear oil.

Next step is to remove the rear seat back and hang off the back while my wife drives.

My old cart mechanic (who moved far away) suggested maybe it’s a motor bearing. He put my D&D motor in about 4 years ago.

So frustrating.

Earlier this year I replaced a broken (at the spline) halfshaft with a pair of the CV halfshafts from NEV. Maybe one of them is bad or dry within the boot?

Got back from hanging off the back while my wife drove around. The noise is very definitely coming from the right rear. Jacked up the Think, and the bearings on the rear right hub are toast (lots of movement—so much so that the halfshaft moves around when canting the wheel). I replaced the wrong side. At least I hope it’s just the bearings.

So your report in post #9 was not quite accurate?
With all that noise I hope the hub is not all wallered out. You might need the big tubes of JB Weld.

I had replaced the left rear bearings with Timkens. Now I’m in the process of replacing the right rear. Hopefully that’ll take care of it!