Noisy Rear-End Rotating Thud

[NAVITEL]

Apologies if this has been covered but I didn't see my exact scenario.

Suddenly, a big thud shook me. It sounds like it is coming from the rear/center of the vehicle but cannot be sure. Like a train starting up, it goes faster and slower as the vehicle does. My first instinct was that one of my tires had gone flat, but upon closer inspection, I saw no damage, leaks or loose components beneath the wheels, and the tire pressure was within normal range.


Even if I'm only a short drive from the dealership, wouldn't it be best to have it hauled in this case?

Does that suit any of the known, prevalent drive train problems?

[honeycut_mazda5]

Adapts its speed to that of the car? Everything from the wheels and axles to the brakes, differential, driveshaft and gearbox is part of the drivetrain. I would highly recommend towing. In the event that an issue arises, the dealer will not be able to blame you for driving recklessly or making matters worse. (I wouldn't take the chance that they may, but it doesn't mean they definitely would.)

It may be something as insignificant as an object caught in a moving component. A steel cable got stuck on my wife's driveshaft years ago when she was passing over something. Out of nowhere, "thump thump, thump"—exactly as you said. I don't know what the odds of that happening again are, but here's hoping it's something nearly that easy for you.

[TechnoTrailblazer]

Just the other week, I had a little twig (or branch, slightly bigger) stuck in my back wheel. Sounds pretty much the same to me. I managed to extract it by squeezing my palm narrowly between the spokes. While you're driving, a little branch inside your wheel or spoke could break off, leaving the remainder stuck behind.

If I hadn't been on the lookout for it, I probably wouldn't have noticed it right away. I would look under your vehicle from the side opposite the source of the noise or, if you think it's related to speed, inside the wheels to see if there's anything there.


It could be anything else, but that's a good place to start. Also, make sure the tyre isn't being scraped by any loose trim pieces (or ones that don't have a push-pin).

[NAVITEL]

Oh great, it seems like the dealer forgot to torque the rear wheel lug nuts to specification when they were changing the oil and rotating the tires on my car. How frustrating!

[honeycut_mazda5]

Make sure there is no damage if the lug nuts are loose enough to make a noise. To ensure that the wheel holes have not been chewed up or ovalled, remove each wheel that is affected and inspect all of the studs.