Increasing Loud Noise From Tire While Accelerating

[billiebob]

Over the past week, i have noticed the tyre noise has been gradually becoming very loud while driving. This noise only occurs when i am rolling and not accelerating. As soon as i accelerate, the noise stops. It is a similar noise to the noise of loud over size mud tyres driving on the road and howling, though is much louder and has never previously happened with my all terrain tyres. Not sure what it is and how it can be fixed. It sounds like it is coming from the front right tyre. Though could be coming from both the front right and left.

See attached photos.

Would appreciate if someone could tell me the problem.

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Same rims as my TJR... same, no caps too. Awesome choice !!

So any chance the noise is from a deteriorating tire? I've had similar symptoms, turned out to be tread delaminating. My tire guy spotted it instantly..... so did I once he pointed it out.

Go to the shop who sold, mounted, balanced, installed the tires.

 

[billiebob]

So I’ve taken it to a mechanic and he said it’s the rear diff. Loose pinion bearing?

Could this be the case? If so, would I need an entire new diff or can this be repaired without doing so?

Loose rear pinion is a common TJ problem..... not that it is neccessarily related to the noise problem tho but a loose pinion eventually needs to be fixed too. I've never "heard" a noise for any loose rear pinion I've had.

Loose pinion is a pretty easy fix.... not in the driveway... but easy for a mechanic in a shop.... maybe a few hours plus $50? in parts.

 

[TJ Hunnicutt]

Yes, it can be the problem.

If you are not familiar with how differentials work, youtube is your friend.
Here's one on the basics of a Dana 44 (one original equipment possibility for what you have in your TJ). With the camera angle he has, the pinion shows up around 6:03.

Here's a 3-parter on a guy rebuilding a Dana 35 (the other, and more likely OE possibility for what you have) with a catastrophic failure in a carrier bearing.

Poke around in youtube and you can learn a lot.

You should feel no side-to-side play in you pinion.