Mystery drive sound

grhowell · February 5, 2020

Okay, so here's the issue. I have a sound that appears to be coming from the front end of my truck. It sounds like a bad bearing (whirring that gets louder with increased speed). However, I had both front bearing replaced in August. I took it in to my mechanic (super honest and reliable). He checked the bearings - both still good. Checked the diff fluid, tranny fluid, and oil - all good. CV boots and drive shafts - good. Drive line and u joints - good. Shocks are less than a year old and are fine. The noise is not impacted by 4wd or 2wd. It is also present if I put it in neutral and coast, so load is not a factor. He put a stethoscope on the truck and tried to pinpoint the noise, but can't find anything. The only thing that may be a lead is that when I tried to put the truck in Neutral by pressing the 2wd and 4low button, it will not go into neutral. I can hear the solenoid click, but it will not release to neutral.

Any and all advice is appreciated - but please, I know it's not the hub/bearing assemblies. They have fewer than 3k miles on them and were inspected two days ago - they're fine.

Truck is a 6.0 with 139k miles on it and I am the second owner. Very clean and meticulously maintained.

vucelick · February 7, 2020

Unfortunately the new hub assemblys can have offshore quality issues. The unit bearing hub assemblys are non-servicable, and they can be bad with no discernable movement in them. i have found that if you leave the tire attached with the truck in the air and pry up and down you can sometimes feel a small amount of movement on a bad one. There should be no movement at all. I am on my second set of hub assemblys in my 8.1 with 172k miles. The the assemblys with timken bearings used to be the good ones, but now its a crap shoot with any of them.

grhowell · February 9, 2020

So if I have a bad bearing... how can I know for sure? Hate to have the shop replace it, and that is not it. It's all still under warranty but the mechanic said it is not the hub. With no movement, no change in sound when turning, it may be hard to convince him to swap it over for free... Nonetheless, it's pretty darn loud, and sounds a heck of a lot like a bad bearing.

grhowell · February 12, 2020

Kept getting louder. Took it back in, and wouldn't you know it - poor quality control from offshore manufacturing. Failed bearing in under 3200 miles. All replaced under warranty. Thanks