Needle bearing or Wheel bearing?

Hey guys, I am at a cross road and dont know what to do. I know there are a million threads on needle bearings but I couldn't find one that answered my question.

My truck has a humming noise that starts at 40 mph. It is speed related and RPM related at all. I believe that the noise is associated with a wheel bearing strictly for the fact that the noise does not get better or go away when I put the truck into 4wd. I have done the wheel bearing test with driving side to side to see if the noise gets better when turning a certain direction and I have not noticed anything. I have jacked the truck up and spun the wheels and checked for play. Nothing seemed to be out of the ordinary.

I hope that someone might give me a beam of light and help me figure out where the damn noise is coming from. Are there any other tests for the driver side needle bearing that I can do, other than putting it into 4wd? Is there another way I can test the wheel bearing?

 

Jack it back up like you did when you were checking for play but this time you're going to spin the wheel with one hand while grabbing the knuckle with the other hand. If the bearing is bad you'll feel roughness through the knuckle and some noise. Even though the wheel is spinning slowly there will be something there. A good bearing will be absolutely smooth and quiet.

Check both sides, if one side is louder then it's bad

 

Is this to test the needle bearing in the Front diff, or to test the wheel bearing?

 

Wheel bearing

The faster you can spin the wheel by hand the better, get a buddy to help..

 

It’s sound like a wheel bearing gone bad.

 

Probably wheel bearing. I had the exact symptoms... humming/ slight vibration felt through the floor only between like 40-55 mph. Replaced needle bearing, which didn't fix the problem (but it was something that I wanted to do anyway for preventative maintenance). Then replaced wheel bearings and it went away. I couldn't feel any play or hear anything when the truck was jacked up, but i could tell the bearing was bad when I had it out of the truck. Sounded real rough.

 

Sounds like we have the exact same problem. What wheel hubs did you get if you dont mind me asking?

 

I got them from somebody here on TW. He presses OEM bearings into generic hubs. This is the thread:
https://www.tacomaworld.com/threads/wheel-bearings-hubs-press-service-4x4-prerunner-nsk.537080/

 

Awesome! I sent him a message. How long ago did you install? I would ask if you like them, but since you referred him I will take that as a yes.

 

About 2 months ago. No issues yet. Lots of happy customers in that thread

 

I am one of those happy customers.

If you are going to do your bearings, then you'd may as well also do the needle bearing, since you are doing 90% of the work getting to it already. And it doesn't cost a whole lot compared to the hub assemblies. And who knows, maybe it's on its way out too. So then, you might as well also change the diff fluid, since you have to drain some and top it off anyway. And when you get in there, you'll realize you need to change out all the axle seals, especially around the failed bearing(s), because they're shot too. Maybe you discover that your brake pads are paper thin when you pull the caliper, so you order some new pads too. But they don't come with new pins and springs, and yours are pretty rusty, so now you're ordering those too. And what a great time to bleed in some fresh fluid, right? And while you're waiting for those parts to arrive, why not also change the rear diff and t-case fluids?

And that's how a "quick" project turns into a whole week of ordering and installing parts.

Here's your cheat sheet for the whole project:



Good luck!

 

Holy crap hahaha. Good call on the CV/ spindle seals though. Mine got damaged so I had to take apart again to replace them because i didnt notice initially.