I have a 1997 F-150 4.6l that I normally drive alone, just me the truck and the radio which is normally played a little on the loud side. The other day myself and some co workers went to lunch and I drove. Needless to say the radio was off. All my co workers said what is wrong with your truck. It sounds like I am driving down the road with nothing around me. It is like a winding or roar that gets worse with increased speed and less when slowing down. All most like the noise you here from offroad tires. I have Michelen street tires. Someone mentioned it might be the ring and pinion? Anyone have any thoughts. Thanks

 

It's a good possiblilty that it could be a bearing or ring and pinion noise. Have you checked the grease level in the rearend?

 

Thanks for the reply LxMan. I just pulled the plug and the fliud level is fine. some did run out the truck backed into the garage is at a slight incline. I did notice what i mopped off the floor was the color of graphite, did not smell to good also. long time since i worked on a rear end and can't remeber what a good / bad sigh in color is.

 

update just pulled the cover. when i remove some gear lube and run in though my finger is is gritty. very fine and i also notice some foaming in the oil?????

 

HMMM, It could be clutch material if it has limited slip.

 

Shane a noise like you're describing is quite often pitted pinion bearings and sometimes carrier bearings. If you remove the driveshaft and rear wheels you can slowly turn the pinion and see if it feels rough at all. It shouldn't.
If the bearings are bad enough the oil will feel gritty and be dark but like Jimmy said that can also be due to clutch material.

 

Thanks, Jimmy and racer guy. I had to drive the truck to work today. So put the cover on and refilled it with the right fluid. Did not add the additive. Fiq just for a road test nope. The 15 mile drive in the noise got louder. So called the shop I use when I don't fix my own stuff. Let ya know what it turns out to be. Again Thanks.

 

Well truck is back after a 1343.00 bill. Total rebuild, but the 1st major repair at 143k Fiq that was fair with a 3year 36 month.

Thanks again guys for the help

 

Glad you got it fixed

 

So what all did they find wrong in there?

 

Racerguy. it was a lost carrier bearing.