Noise from rear axle, driveline "thunks" when wheels are off the ground

So first things first. I didn't notice this until recently because I can't hear the sound when my windows are up, and most of the time I have my windows up while driving. The other day I had my windows down going through an alley and I heard a weird almost grinding sound that sounded rotational with my tires rotating. I could only hear it at low speeds, when I pick up the speed the sound goes away. I haven't got a chance to get that on video cuz I could only replicate it when the truck is moving and I can't hear it on the video. When I try to take it from inside the cab.

Today I decided to jack up the rear and spin the tires around to see if I could get that sound. That sound does not replicate at all, but I did find this thunking sound coming from the driveline, whenever I first spin the tires. Video:

https://youtu.be/x3BGYDIDdhg

I'm assuming that I really just need to grease my u-joints as I haven't done that yet since I bought the truck in October. Anything else that could be going on here? Normal?

As for the original sound, I'll try to get some video of it so I can show you guys, but I have a feeling it's going to be my rear wheel bearings. The thing is the previous owner has these listed as replaced about 40,000 mi ago...
"Replace rear axle bearings and seals" with no other details in the line item. Hmmmmm. I also start hearing a weird knocking sound like every 3 seconds when going kind of slow. But it's not constant. It only happens once in awhile.

What are your guys's thoughts before I start tackling this?

 

Drivetrain lash. Red folks can grease the U joints.

 

That's gonna be my first plan of action. Thanks.

 

Yea, thats fine. Try to get some vid of the noise from 0-20mph

 

Get under there and check the condition of the center carrier bearing. The rubber and bearing should all be firm against side to side and up and down movement. Also your u joints do sound rough in that same location. Try to wiggle around by hand while under the truck.

 

Also look for pinion play. With the wheels on the ground & trans in park, have someone push the truck back/forth there shouldnt be alot of in/out movement where the driveshaft attaches to the axle. Fsm should have a tolerence spec. I'd guess lsss than 1/8".

 

I went under there last night and checked the carrier bearing. Visually the rubber looks good. There is a bit of play, maybe 1/8th to 1/4 of an inch up and down and it seems less side to side. My research tells me that's normal but I'll try to get some video of it.

 

Thanks I'll check that today.

 

But did you do the same to that nearby u joint? That sucker shouldn't wobble. None of them should be loose at all.

 

No I didn't. I'll give it a shakedown after work today. Took my matrix to work. More boring, more efficient LOL. just to clarify, I haven't heard any of this thunking at all while driving. This is the first time I noticed when I jacked up the tires and rotated them.

 

Well, it is normal to have a little clunk when jacked up and changing directions or starting and stopping. So, you are probably okay there. However, you probably wouldn't be investigating if you weren't sensing something extraordinary. At this point, all I can suggest is a tool called a chassis ear. It is an electronic device that allows you to place listening devices around the chassis and listen as you drive and replicate the problem. Pretty useful, not terribly expensive, various models. Just Google Chassis Ear for details if you think it would be helpful. Good luck!

 

Here's a little update:

I decided to check the easy stuff first then drive so I could pinpoint exactly what that faint grinding noise was at low speeds. I took my rear tires off and when I was taking them off I noticed that a few of the lugs weren't as tight as they should be. My fault. I was the one who removed them about a month ago. A tiny bit of sand was against the hub, and a little bit of what looked like rust flakes that I had to brush off. After that I put all the tires back on and took it for a test drive. The grinding sound is completely gone. I drove it about 3 mi on the freeway, slow speeds, hard stops, etc, the sound is gone.

Edit... Speaking of sand... I was in the desert a month ago and we got into some really deep fluffy sand. I put in a four-wheel drive and hauled ass threw it because I was worried I was going to get stuck. It wasn't till about after that that I started noticing the sound.


As for the driveline, I'm going to go ahead and grease all that up and call it good. I checked all my u-joints and everything seems fine. The carrier bearing seems normal from what people have told me a little bit of play when it's jacked up is fine.

I'll update you if any other noises happen. Thanks for the help guys.

 

One piece of advice... If you're coming from another vehicle, The tundra cab is pretty well insulated it seems. A lot more than a second gen Tacoma. I swear I could hear a squirrel fart up in a tree from inside my cab with the windows up. In the tundra, I could hardly hear anything outside. So once in awhile roll your windows down when you're cruising around town and just listen to your vehicle. I didn't notice the sound until I had my windows down and I was rolling up to a drive-thru

 

This is why if I am even a little skeptical of a vehicle's condition or pushing it hard, I will not drive with the radio on. I become somewhat fused to the sounds and feels of the vehicle. However, once stopped it's time to open them doors and let the entire county enjoy or hate my favorite songs!

 

Getting gas at Walmart the other day I was forced to endure the guy at the next pump blaring Dah, Dah, DahDah by Nardo Wick. No thanks…