Growling noise front end

[frankie15oct]

My 99 Explorer 4x4 has a growling sound in the front end. It doesn't seem to come from one side specifically. It's also not a grinding or metallic noise per say. It seems to increase with speed and when I let off the throttle is seems to go away? No noises when turning, like a CV and no driveshaft play like a u joint. My first thought is bad pinion bearing but, hope that it may be another simpler fix. Anybody familiar with this? Any help would be greatly appreciated!

Also, Tires are stock replacements Goodyear wrangler rt/s so I do not believe tires are the problem, fresh front end alignment as well

 

[SoNic67]

Front drive shaft.

 

[imp]

Pinion gears spin VERY fast. So, when bearings give out there, the noise is not a growl, but usually high-pitched, a whine with rumble in it, depending on how bad they have become. If ignored awhile, the relationship of the gear teeth meshing together, as the pinion itself can "move" up and down a tiny bit due to bad bearing(s), can be disrupted to the point of making extreme noise, and damaging the gear tooth surfaces.

If allowed to go that far, yer in for big trouble! The best pinpoint check for locating the noise that I've found, is to "stethoscope" the differential case below the pinion, and the wheel hubs, while having someone run it up in gear on jackstands. This must be done with caution to avoid injury, but has successfully located the noise source for me many times. imp

 

[frankie15oct]

Thanks for the replies. I do not feel any play at pinon bearing but may attempt the stethescope check. Also considered driveshaft. May try removing it and see if the noise stops. Thanks again!

 

[frankie15oct]

The sound I get sounds very similar to mud tires on pavement. Maybe just a little higher pitch. No clicking or grinding. No vibrations. Without tearing into everything, I am puzzled

 

[matt351]

Mine is doing the same thing right now.

 

[frankie15oct]

If you find a solution, please share!

 

[shadowless127]

Does the sound change if you turn your steering wheel to the left or right?

 

[frankie15oct]

No this sound tends to stay the same. sometimes noticeable at low speeds, sometimes noticeable at low and high speed

 

[SoNic67]

Like I said, if noise is not related to steering (hubs) then is 80% chance that is the CV joint in the front drive shaft.

Mine started to make noise almost "over night". And got louder in 24 hours...

 

[frankie15oct]

Thanks! The boot looks good, no noticeable play. It's is one of the hardest to inspect unfortunately

 

[drdoom]

I had that mud tire sound on my Explorer, hub replacement helped that. Now I have same sound coming from the back my Taurus.

 

[SoNic67]

Thanks! The boot looks good, no noticeable play. It's is one of the hardest to inspect unfortunately

Mine looked fine too. Is not hard to remove the shaft, and if you have 4x4 you can drive without it for longer time, till you get the parts (my AWD doesn't like that).

 

[frankie15oct]

Thanks for all the replies! No one mentioned bad gears, that's a relief! Hopefully it will be a smaller, less expensive problem than the front diff!